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Nitrite is widely used in production and daily life, and detecting this substance has always been crucial for human health or environment monitoring. Here, a dual-emitting dye@MOF composite, EY@UiO-67-CDC-(CH 3) 2 , has been constructed and demonstrated that this material could detect nitrite ions with highly selective and anti-interference properties. By incorporating an organic anionic dye (Eosin Y) within a cationized EY@UiO-67-CDC-(CH 3) 2 framework through the post-synthetic method, the composite presents an effective combination due to electrostatic attraction. It features a dual emission effect, which belongs to the blue emission of MOF at 428 nm and yellow emission of EY at 559 nm, respectively. After adding NO 2 −, the fluorescence emission peaks of EY and MOF showed opposite changes due to the inner filter effect of NO 2 − and MOF, as well as effective excitation of the dye's fluorescence and slight dye leakage. Therefore, I dye /I MOF is used as the detection signal value instead of absolute fluorescence intensity, effectively reducing the detection limit to 0.224 μM and improving its detection accuracy. In addition, during the detection process, the fluorescence sensor showed noticeable color changes, so a smartphone-based analytical device without additional instruments was developed for the quantitative, visual analysis of nitrite by identifying the RGB values of the fluorescence sample solution, with a detection limit of 6.74 μM. The application of the sensor visualizes nitrite detection and reduces the cost of detection, providing a feasible method for on-site detection of nitrite in water samples. By incorporating an organic anionic dye (Eosin Y) within a cationized EY@UiO-67-CDC-(CH 3) 2 framework through the post-synthetic method, the composite presents a dual emission effect due to electrostatic attraction. [Display omitted] • An ultra-sensitive ratiometric fluorescence Sensor for detecting of nitrite. • Effectively reducing the nitrite detection limit to 0.224 μM. • Instrument-free quantitative and visual analysis of nitrite. • As a dye@MOF fluorescent test strip, it realizes portable detection of nitrite. [ABSTRACT FROM AUTHOR]

The incorporation of photoresponsive component into metal-organic frameworks (MOFs) is intriguing because they can confer additional properties such as photomagnetic behavior, light-controlled electrical conductivity, and photocatalysis. Naphthalene diimide (NDI) is organic dye that absorbs visible light and have π-electron-deficient planes and photochemical characteristics. NDIs are ideal for creating photoactive MOF materials due to their ability of undergo reversible single-electron reduction and form stable radical anion. In this work, a photoactive MOF material, Mn 2 (BNDI) 2 (DMF) 3 (1) (H 2 BNDI = N,N' -bis(3-benzoic acid) naphthalenediimide), is fabricated and found to exhibit not only notable photochromism (light yellow to dark brown), but also reactive organic radical under ambient conditions. Complex 1 can act as an efficient electron-transfer photocatalyst for selective oxidation of 2,6-di- tert -butylphenol (2,6-DTBP) into various compounds under diverse reaction conditions, without the need for supplementary co-catalysts. Specifically, 2,6-DTBP is photocatalyzed to form 2,6-di- tert -benzoquinone and its dimer in methanol solution, 2,6-DTBP is converted to trimers and 3, 5-di- tert -butyl-4-hydroxybenzaldehyde in ethylene glycol with medium yield. This work will provide new perspective for the fields of NDI-based MOFs and photocatalysis. A photochromic MOF based on the NDI derivative has been developed for selective photocatalytic oxidative C–C coupling of 2, 6-di- tert -butylphenol to different products by controlling the reaction conditions. [Display omitted] • A photoactive MOF was prepared based on the naphthalene diimide derivative. • Complex 1 exhibit fast-responsive photochromism upon UV–Vis light irradiation. • Complex 1 shows selective photocatalytic oxidative 2, 6-di- tert -butylphenol to different products. [ABSTRACT FROM AUTHOR]

Azo dyes are difficult to degrade, dark in color and toxic in the aqueous environment, which will harm the ecological environment and human health if left untreated. Photocatalytic technology has a wide range of applications in the treatment of printing and dyeing wastewater; in the present study, nano Zr–BiOI/GO photocatalytic composites were prepared by a hydrolysis method using Bi(NO 3) 3 –5H 2 O and ZrOCl–8H 2 O as precursors and GO as carriers. The structure and properties of the samples were characterized by combining test methods such as XRD, FESEM, TEM, XPS, and UV–vis. Congo red (CR) was used as the target pollutant to assess the photocatalytic performance of the prepared materials. The results showed that the specific surface area of 10 % Zr–BiOI/GO increased from 21.98 m2/g to 152.79 m2/g, and the average particle size decreased from 21.61 nm to 17.75 nm compared with that of BiOI. Compared with BiOI, the light-absorption threshold of 10 % Zr–BiOI/GO was increased from 640.6 to 726.4 nm, and the forbidden bandwidth was decreased from 1.94 eV to 1.71 eV. In addition, the nanocomposites exhibited excellent stability and removal of organic dyes and could be used as a potential photocatalyst for water remediation under visible light. The removal of CR by 10 % Zr–BiOI/GO composite was 95.42 % at 120 min. The photocatalytic degradation process of Zr–BiOI/GO conformed to the first-order kinetic model, and the correlation coefficient of the kinetic curve of 10 % Zr–BiOI/GO was 0.9465 and the reaction rate constant was the greatest at 0.0221 min−1. Superoxide radicals [·O 2 −] play a major role in photocatalytic activity. The results indicate that nanocomposites are a promising candidate for photocatalytic degradation of water pollutants. In this paper, Zr–BiOI/GO photocatalytic composites were prepared by a simple hydrolysis method, which possessed higher specific surface area and narrower forbidden bandwidth than pure BiOI, and could remove up to 95.42 % of Congo red (CR) solution under visible light, in addition to the high stability and recycling rate of Zr–BiOI/GO. [Display omitted] • The pore structures of Zr–BiOI/GO photocatalytic materials prepared by hydrolysis method were well developed. • The maximum removal of Congo red by mesoporous Zr–BiOI/GO photocatalytic material was 96.84 %. • Paradigm of Zr–BiOI/GO resource recovery and wastewater treatment was provided. • Long-term experiments were conducted with excellent stability. [ABSTRACT FROM AUTHOR]

Converting the solid waste into high-value products were significant to environmental protection and resources saving. Waste cigarette filters, were made of cellulose acetate, a common kind of solid waste in daily life. In this work, waste cigarette filters were used as cellulose precursors and decorated with bimetallic MOFs to fabricate a light-weight, monolithic and porous carbon foam. The specific surface area and pore size of as-prepared carbon foams can be regulated through changing the mass ratio of ZIF-8 to ZIF-67. Importantly, as-prepared samples exhibited good electrochemical performances when accessed a great balance between the surface area and conductivity. The sample of C/Zn/Co-0.5:0.5 exhibited an excellent electrosorption capacity for methylene blue, which was high up to 2847 mg g−1. Moreover, it had a superior stability, and the removal efficiency for methylene blue remained above 90 % after 5 cycles. Thus, this study successfully realized the conversion of waste cigarette filters into porous materials, which can be regarded as an effective and economic adsorbent used in wastewater treatment. [Display omitted] • The waste cigarette filters can successfully convert into highly efficient adsorbent. • The sample of C/Zn/Co-0.5:0.5 accessed great balance between the surface area and conductivity. • The obtained carbon foam exhibited excellent electrosorption for methylene blue of 2847 mg g−1. • The removal efficiency maintained above 90 % after 5 cycles. [ABSTRACT FROM AUTHOR]

In the present study, new oxygen deficient triple layered Ruddlesden-Popper (RP) phases LaSr 3 Fe 3- x Cr x O 10-δ (x = 0.0, 0.2, and 0.5) have been prepared via sol-gel procedure. The prepared n = 3 RP phases were characterized with various characterization techniques in order to visualize the effect of Cr3+ doping on structural, optical, magnetic and photocatalytic properties. Rietveld structural refinements showed that all the phases crystallized in the I4/mmm space group with tetragonal symmetry. Dominant anti-ferromagnetic (AFM) interactions (Fe3+―O―Fe3+ and Fe4+―O―Fe4+) were noticed in each of these oxygen deficient triple layered phases with presence of weak ferromagnetic (FM) interactions. The decline in the values of Neel temperature (T N) with Cr doping has been interpreted on the basis of increase in FM Fe3+―O―Cr3+ interactions. The energy band gap values (E g) of all the synthesised oxygen deficient phases vary from 1.63 to 1.73 eV, which makes them excellent photocatalysts for dye decontamination. Furthermore, the photocatalytic performance of the prepared phases was assessed by utilizing rhodamine B (RhB) dye as model dye pollutant. It was found that LaSr 3 Fe 2.5 Cr 0.5 O 9.17 photocatalyst showed excellent results in the removal of RhB dye. As a result, we were further encouraged to extend the degradation to some other organic dyes such as methylene blue (MB), methyl orange (MO) and their mixture (RhB + MB + MO). Time dependent UV–vis absorbance spectra for the photo-oxidative degradation of RhB dye by LaSr 3 Fe 3- x Cr x O 10-δ catalyst. [Display omitted] • Synthesis of new oxygen deficient triple layered RP phases LaSr 3 Fe 3- x Cr x O 10-δ. • Dominant AFM interactions were noticed all phases along with weak FM interactions. • The decline T N with Cr doping has been interpreted on the basis of increase in FM Fe3+―O―Cr3+ interactions. • E g values vary from 1.63 to 1.73 eV making them excellent photocatalysts. [ABSTRACT FROM AUTHOR]

The high electron-holes recombination rate in pure graphitic carbon nitride (C 3 –N 4) restrict their photocatalytic efficiency. In this research work, we successfully immobilized Ag 3 PW 12 O 40 a polyoxometalate-base crystal on graphitic carbon nitride 2D sheet through physical grinding method to prevent charges recombination on the surface. Both the materials were prepared separately and then grinded after mixing, to get C 3 –N 4 @Ag 3 PW 12 heterojunction. The prepared C 3 –N 4 @Ag 3 PW 12 composites were tested with different characterization techniques to confirm its structural integrity and successful fabrication of heterojunction. The composite catalyst showed expansion in UV light absorbance where it promotes from 406 nm to 454 nm for pure C 3 –N 4 and composite C 3 –N 4 @Ag 3 PW 12 -30 % respectively. The composite showed better electron-holes separation, confirmed from its electrochemical performance such as TPC (total photocurrent) and PL data. The prepared catalysts were tested for the degradation of two types of organic dyes such as methylene blue and Rhodamine B under photoirradiation. The C 3 –N 4 @Ag 3 PW 12 -30 % composite photocatalyst showed efficient photocatalytic activity and removed 99 % methylene blue in 75 min while removed 99.4 % Rhodamine B in 60 min while the pure Ag 3 PW 12 and C 3 –N 4 could only remove 26.3 % and 37.7 % methylen blue and 43.54 % and 53.38 % rhodamin B respectively, in the same conditions. The results show that, the Ag 3 PW 12 crystals deposition on C 3 –N 4 2D sheets is a preferred approach to enhance the catalytic performance of C 3 –N 4 2D sheet. [Display omitted] • Ag 3 PW 12 O 40 was immobilized on graphitic C 3 –N 2D sheet through physical grinding method to prevent charges recombination on the surface. • TPC (total photocurrent) and PL data confirmed that the composite showed better electron-holes separation. • The C 3 –N 4 @Ag 3 PW 12 -30 % composite removed 99 % methylene blue in 75 min while removed 99.4 % rhodamin B in 60 min. [ABSTRACT FROM AUTHOR]

It is a very effective strategy to capture and separate carbon dioxide by incorporation of alkali cations into MOFs. Presented here is an anionic metal-organic framework (MOF) (Me 2 NH 2) 2 Co(tpta)·2H 2 O (1), in which the exchange of alkali ions (Li+ and Na+) took place with H 2 N(Me) 2 + cations. As expected, CO 2 /N 2 selectivity of the framework was improved significantly and reached 61.6 due to the inclusion of Li + using the ideal adsorbed solution theory (IAST) model. The enhancement of its CO 2 uptake capability and selectivity has been mainly attributed to the charge-quadrupole interaction. For the CO 2 /N 2 system, it is found that the inclusion of Li+ rather than Na+ favors higher selectivity. Additionally, it successfully separated cationic dye crystal violet (CV+) from anionic dye methyl orange (MO−) by the column-chromatography. Evidently, the enhancement of the electrostatic interaction greatly improves the separation performance of the framework. Presented here is an anionic MOFs (Me 2 NH 2) 2 Co(tpta)·2H 2 O (1), in which the exchange of alkali ions took place with H 2 N(Me) 2 + cations. Most interestingly, CO 2 /N 2 selectivity of the framework reached 61.6 due to the inclusion of Li+. Additionally, it successfully separated cationic dye CV+ from anionic dye MO− by the column-chromatography. [Display omitted] • The exchange of alkali ions took place with H 2 N(Me) 2 + cations in an anionic MOF (Me 2 NH 2) 2 Co(tpta)·2H 2 O (1). • CO 2 /N 2 selectivity of the framework reached 61.6 due to the inclusion of Li + using the IAST model. • It successfully separated cationic dye CV+ from anionic dye MO− by the column-chromatography. • The enhancement of electrostatic interaction greatly improves the separation performance of the framework. [ABSTRACT FROM AUTHOR]

The perturbation in the environment by the discharge of toxic dyes in wastewater is a matter of concern and there is an urgent need to impart the balance. These organic dyes can be removed via catalytic degradation, adsorption or membrane filtration. In this study, we have developed a Zn(II)-based coordination polymer (CP) [Zn(bpyp)(HL-NO 2) 2 ] n (1) by solvothermal method using 2,5-bis(pyrid-4-yl)pyridine (bpyp) and 4-nitrobenzoic acid (HL-NO 2) as organic linkers. The single crystal X-ray diffraction depicts that the Zn(II) adopts a tetragonal coordination environment and 1D linear chains are linked together to form a 2D framework via hydrogen bonding and π-π interactions. Methyl orange (MO), methyl violet (MV), methyl blue (MB) and rhodamine B (RhB) were investigated for photocatalytic degradation in the presence of visible light. Synthesized 1 shows 82% degradation of RhB dye. The Hirshfeld surfaces study demonstrated that these synthesized coordination polymers contain various forms of intermolecular contacts (C⋯C, H⋯C, H⋯H, and O⋯H). The degradation efficiency of organic dye by 1 was discussed. The active species involved in the degradation of Rh B has been assessed using trapping experiments. [Display omitted] • [Zn(bpyp)(HL-NO 2) 2 ] n (1) were synthesized. • The degradation efficiency of RhB by 1 was very high compared to other dye. • The active species involved in the degradation of Rh B has been assessed using trapping experiments. • Hirsfeld d norm surface of carboxylate are mainly covered by H⋯O/O⋯H, C⋯H/H⋯C and H⋯H interactions. [ABSTRACT FROM AUTHOR]

In order to improve the visible light catalytic activity of TiO 2 , the TiO 2 @g-C 3 N 4 (TCN) composite catalysts with three-dimensional porous structure and rich active sites were prepared by hydrothermal method and calcination method orderly. The synthesized TCN composites microstructures were thoroughly characterized and their performance for the photocatalytic degradation of organic dyes was investigated. The results show that the prepared composites formed the heterojunctions with a core-shell structure, which can effectively broaden the absorption spectrum of TiO 2 to visible light region. In the degradation experiments, the TCN composites exhibited excellent photocatalytic degradation effect on organic dyes, which can reach 99.65% under visible light irradiation for 2 h. The strong acid condition was benefit to the catalytic process. After five cycles of testing, the degradation efficiency of organic dyes can still maintain at 95.62% level, which indicate that the TCN composites had excellent visible light catalytic activity and reusability. [Display omitted] • The TiO 2 with three-dimensional porous structure and rich active sites were prepared by hydrothermal method. • The melamine can penetrate into the interior of TiO 2 microsphere to form TCN heterojunctions with core-shell structure. • The TCN composites with core-shell structure heterojunctions can degrade organic dyes efficiently. • The TCN composites have good stability and repeatability. [ABSTRACT FROM AUTHOR]

A two-dimensional Cu(II) MOF {[Cu 2 (OH)(mtrb)(suc) 1.5 (H 2 O) 2 ]·H 2 O·0.5DMA} n (Cu(mtrb)) (mtrb = 1,3-bis((1,2,4-triazol-4-ylmethyl)benzene, H 2 suc = succinic acid, DMA = N, N-dimethylacetamide) was obtained using solvothermal synthesis. Cu(mtrb) has a two-dimensional (6,3) network with the point symbol of 63. A series of Cu(mtrb)/wt%g-C 3 N 4 composites were obtained by coupling Cu(mtrb) and semiconductor g-C 3 N 4 to give heterojunctions by the grinding method. The composite samples were investigated with XRD, FT-IR, SEM, EDS, XPS, TGA, UV–Vis, PL and EIS to analyze the purity, functional groups, surface morphology, elemental distribution, valence electron, thermal stability, visible-light absorption and electron-hole pair separation status. Photocatalytic degrade methylene blue (MB), methyl orange (MO) and rhodamine B (RhB) were investigated. Cu(mtrb) can degrade 93.6% MB in 30 min, 87.0% MO in 135 min and 92.0% RhB in 90 min. Cu(mtrb)/10%g-C 3 N 4 could degrade 96.2% MB in 15 min, 87.0% MO in 45 min and 92.3% RhB in 60 min, respectively. The coupling of Cu(mtrb) with g-C 3 N 4 resulted in the formation of heterojunctions in Cu(mtrb)/wt%g-C 3 N 4 composites and inhibited the rapid recombination of electron-hole pairs. The main reactive species for MB degradation were •OH and h+. Cu(mtrb) and Cu(mtrb)/10%g-C 3 N 4 composites are the good photocatalysts. A 2D Cu-MOF Cu(mtrb) and a series of Cu(mtrb)/wt%g-C 3 N 4 composites were synthesized and characterized. Cu(mtrb) can degrade 93.6% MB in 30 min, 87.0% MO in 135 min and 92.0% RhB in 90 min. Cu(mtrb)/10%g-C 3 N 4 could degrade 96.2% MB in 15 min, 87.0% MO in 45 min and 92.3% RhB in 60 min, respectively. The main reactive species for MB degradation were •OH and h+. Cu(mtrb) and Cu(mtrb)/10%g-C 3 N 4 are the good photocatalysts. [Display omitted] • A Cu-MOF Cu(mtrb) and its g-C 3 N 4 composite were synthesized and characterized. • Cu(mtrb) can degrade 93.6% MB in 30 min, and Cu(mtrb)/10%g-C 3 N 4 could degrade 96.2% MB in 15 min. • Cu(mtrb)/10%g-C 3 N 4 could degrade 87.0% MO in 45 min and 92.3% RhB in 60 min. • The main reactive species for MB degradation were.•OH and h+. • A Cu-MOF Cu(mtrb) and Cu(mtrb)/10%g-C 3 N 4 composite are the good photocatalysts. [ABSTRACT FROM AUTHOR]

A microporous metal-organic framework (MOF) with ttd-type topology, [Mn 2 (FDDI)](DMF) 5.5 (H 2 O) 4.5 (Mn-MOF ; H 4 FDDI = 5,5'-(9H-fluorene-2,7-diyl)-diisophthalic acid (DMF = C 3 H 7 NO) was solvothermal obtained and characterized. Mn-MOF contains three different channels that show excellent removal of low concentration of crystal violet as compared with methyl orange and methylene blue from the aqueous solution at 298 K. A novel microporous metal-organic framework (MOF) with ttd-type topology has been obtained that exhibited excellent removal of low concentration of crystal violet (CV+) as compared with methyl orange (MO−) and methylene blue (MB+) from the aqueous solution at room temperature. Image 1 • A novel microporous MOF Mn-MOF was synthesized and structurally characterized. • Mn-MOF has three different types of channels and exhibits ttd-type topology. • Mn-MOF shows excellent removal of low concentration of crystal violet (CV+). [ABSTRACT FROM AUTHOR]

Four novel Co(II)-MOFs based on the 3,3′-azodibenzoic acid (H 2 L), namely [CoL (bimb) 0.5 ] n (1), {[CoL (bimmb)]·DMF} n (2), [CoL (bimmb) 0.5 ] n (3), and [CoL (bbibp)] n (4) (bimb = 1,4-bisimidazole, bimmb = 4-bis(imidazole-1-ylmethyl)benzene, bbibp = 4,4′-bis(benzoimidazo-1-yl)biphenyl and DMF = N, N′-dimethylformamide) have been synthesized under solvothermal conditions and characterized by elemental analysis, IR spectra, powder X-ray diffraction (PXRD), thermogravimetric (TG) analysis and single crystal X-ray diffraction. Single crystal X-ray diffraction analysis shows that complex 1 and complex 3 possesses the same structure as uninodal 6-connected 3D (three-dimensional) pcu topology framework with the point symbol (412.63), whereas complex 2 possesses an uninodal 3-connected hcb topology framework with the point symbol (63) and complex 4 displays a 4-connected sql topology framework with the point symbol of (44.62). In addition, the photocatalytic degradation properties of the four complexes have been investigated. Significantly, complex 4 is the best photocatalyst for the degradation of three organic dyes (MV/MB/RhB). Complex 2 is the good photocatalyst for the degradation of two organic dyes (RhB/MB). Complex 3 is the good photocatalyst for the degradation of two organic dyes (MV/MB) and complex 1 is the good photocatalyst for the degradation of only one organic dyes (MV). Image 1 [ABSTRACT FROM AUTHOR]

Crystalline organic hybrid metal chalcogenides have exhibited effective photocatalytic degradation ability for organic pollutants. However, few strategies have been applied to enhance its inherent photocatalytic degradation activity. Here, we used an organic hybrid indium sulfide [In 8 S 13 (S) 1/2 (SH)][In 4 S 6 (S 3) 1/2 (SH)](TMDPH 2) 5 (HCF-1) (TMDP = 4,4′-trimethylenedipiperidine) as pristine material, by immersing HCF-1 into AgNO 3 solution, the surface of HCF-1 crystal was decorated by Ag+ ions via electrostatic interaction. Compared with the pristine HCF-1, the as-modified Ag@HCF-1 exhibited enhanced photocatalytic degradation performance for organic dyes (RhB and MO) and antibiotics (TC and ENR). The decoration of Ag+ ions on the surface of HCF-1 can broaden the range of light absorption, and promote the separation of photo-generated carriers, and thus boost the photocatalytic activity. In addition, photocatalytic mechanism was studied by free radical capture experiments, which proved the dominant roles of h+ and •O 2 − in the degradation process. [Display omitted] • The surface of an organic hybrid indium sulfide was modified by Ag + ion decoration. • Ag@HCF-1 displayed enhanced photocatalytic degradation ability for organic dyes and antibiotics. • Mechanism study proved the dominant roles of h+ and.•O 2 − in the degradation process. [ABSTRACT FROM AUTHOR]

Abstract We study adsorption behaviors of isomorphic metal-doped metal-organic frameworks in the field of dyeing wastewater treatment technology. Herein, a series of 3D isostructural Co2+/Cd2+ metal-doped metal-organic frameworks named compounds 1 – 5 were successfully synthesized under hydrothermal conditions and used in adsorbing and separation dyes. We demonstrate that dye molecules can be adsorbed on the external surface of the MOFs and their loadings can be tuned by adjusting the rate of the central metal atoms. We show that compound 5 crystals containing Cd2+ are selective adsorbent for pH, temperature, ionic strength responsive adsorption. Their adsorptive properties of cationic dyes in aqueous solutions are higher than that of neutral and anionic dyes. Our method of isomorphic metal-doped opens new possibilities to construct adsorption strength regulation systems for a wide range of applications and facilitates new efforts in environmental purification. Graphical abstract fx1 Highlights • Study on the effect of metal ions on the adsorption of dyes by isomorphic metal doping. We characterize the synthesized compounds, which adsorb a series of dyes (cationic, neutral and anionic dyes). • Some typical organic dyes such as Methylene Blue(MB), Methyl Violet(MV), Phenol Red(PR), Methyl Orange(MO) and Congo Red(CR) were selected as targeted models. For compounds 1 – 5 doped with different contents of metal, the adsorption amount of MV increased with the increasing content of Cd2+ which is in the frameworks. The compound 5 has maximum adsorption amount which can reach 5.93 mg g−1. • Compounds 1-5 have the adsorption capacity for cationic dyes, and the adsorption capacity for MV is better than MB. Compound 5 almost don't carry the neutral dye PR, while compound 5 hardly adsorb anionic dye, such as MO and CR. • We study many factors (pH, temperature, ionic strength)of the adsorption of dye on the compound 5. The experiment shows that the increase of temperature is beneficial to the adsorption in a specific range and the dye adsorption is better under alkaline conditions. • Compound 5 successfully adsorbed MV and MB from mixed dyes with removal percentages of 80% and 90%, respectively. it is stable in the solvent environment. The recyclability of compound 5 adsorbed MV which was investigated over five cycles, the fluctuation of the adsorption capacity was less than 5%. Perform correlation calculations between adsorption kinetics and thermodynamics. [ABSTRACT FROM AUTHOR]

Metal organic framework (MOFs) have been attracted a great attention as a new type photocatalysts due to their unique properties. In this work, the new hybrid photocatalyst based on fabrication hybrid structures between MIL-100(Fe) and Bi 2 S 3 (MIL-100(Fe)@Bi 2 S 3 ) were synthesized via simple hydrothermal method. The photocatalytic degradation of Rhodamine B (RhB) over the as-prepared samples showed that the hybrid photocatalyst samples had higher photocatalytic performance compared to the individual components (MIL-100(Fe) and Bi 2 S 3 ). The higher photocatalytic performance of the hybrid photocatalysts was proved by electrochemical and photoelectrochemical analysis such as electrochemical impedance spectroscopy (EIS) and also photocurrent measurement. In addition, the possible photocatalytic mechanism based on the optical, photoelectrochemical and quenching tests was proposed. [ABSTRACT FROM AUTHOR]

The rational design and preparation of low-cost and visible-light-active catalysts for photodegradation of methylene blue (MB) have been regarded as an efficient way for the utilization of solar energy to address the environmental issues. Herein, in this work, a novel MoS 2 /CdS/Bi 2 MoO 6 ternary Z-scheme heterojunction to be applied in pollutant photodegradation is fabricated via hydrothermal method. Under visible light illumination, the as-prepared 2.4% MoS 2 /CdS/Bi 2 MoO 6 -2.0 composites display desirable photocatalytic activity with removal efficiency of 96.0% towards MB and the total organic carbon removal rate of 73.5% within 120 ​min. The apparent reaction rate constant of 2.4% MoS 2 /CdS/Bi 2 MoO 6 -2.0 (0.0256 min−1) is approximately 16 and 5.2 times higher than those of pure Bi 2 MoO 6 (0.0016 min−1) and CdS (0.0049 min−1), respectively. Meanwhile, the as-prepared ternary photocatalyst possess favorable universality. Combined with a series of characterization results, the enhanced photocatalytic activity of 2.4% MoS 2 /CdS/Bi 2 MoO 6 -2.0 is mainly attributed to the successful formation of the ternary Z-scheme photocatalysts, which could boost the separating/transferring efficiency and reduction/oxidation ability of charge carriers. In addition, the cycling experiments demonstrate that 2.4% MoS 2 /CdS/Bi 2 MoO 6 -2.0 possesses favorable stability and recoverability. Overall, this work put forward a simple strategy for synthesizing visible-light-active ternary Z-scheme photocatalytic materials. MoS 2 /CdS/Bi 2 MoO 6 ternary Z-scheme heterojunction has been successfully prepared via hydrothermal method, which exhibit the greatest photocatalytic activity with 96.0% of MB removal efficiency under visible light illumination. [Display omitted] • Preparation of MoS 2 /CdS/Bi 2 MoO 6 Z-scheme heterojunctions via a hydrothermalmethod • MoS 2 /CdS/Bi 2 MoO 6 heterojunctions inhibit the recombination of photogenerated carries. • MoS 2 /CdS/Bi 2 MoO 6 exhibits high photocataltic degradation efficiency. [ABSTRACT FROM AUTHOR]

In present study, a stable and magnetic metal-organic framework (MOF) material was synthesized by simple solvothermal method as adsorbent to rapid removal of two organic dyes, the Rhodamine B (RB) and Rhodamine 6G (Rh6G), in water samples. The prepared material showed great characteristics of large surface area (519.86 m 2 g −1 ), excellent magnetic responsivity (35.00 emu g −1 ) and rapid removal (within 5 min). Maximum adsorption capacities of the magnetic material toward RB and Rh6G were up to 219.78 and 306.75 mg g −1 , respectively. Adsorption kinetics suggested the adsorption process met the pseudo-second-order kinetic model. The prepared material could be reused at least 10 times by washing with acetonitrile solution, the relative standard deviation (RSD) of these ten cycles removal efficiency was 4.8%. In conclusion, good chemical inertness, a mechanical/water stability and super-hydrophilicity feature made this MOF a promising adsorbent for targets removal from environmental water sample. [ABSTRACT FROM AUTHOR]

In this paper, two novel zeolitic imidazole framework (ZIF) materials, ZIF-9 and ZIF-12 were firstly introduced as catalysts to activate PMS for Rhodamine B degradation. ZIF-9 and ZIF-12 have the same composition in metal ions (Co 2+ ) and organic linker, but show different structural topologies (SOD and RHO, respectively) and particle size. The two ZIFs were successfully synthesized and characterized via SEM and PXRD. Both ZIF-9 and ZIF-12 as the PMS activation catalysts were evaluated and compared, and the underlying mechanism was proposed. The nanoscale nature enables ZIF-9 a closer contact with PMS, which leading to degradation rate ZIF-9 > ZIF-12 at the time of 5 min (54.8% and 27.7%, respectively). And the degradation of ZIF-12 gradually caught up with ZIF-9 when the reaction time was longer, which can be attributed to the RHO topology and larger cage size of ZIF-12. The efficient degradation of RhB indicates that ZIF-9 and ZIF-12 can be promising heterogeneous catalyst to activate PMS for the degradation of RhB. [ABSTRACT FROM AUTHOR]

A cube-like porous ZnO architecture was synthesized by direct two-step thermolysis of a zinc-based metal-organic framework [(CH 3 ) 2 NH 2 ][Zn(HCOO) 3 ]. The obtained ZnO microcube was characterized by powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy and nitrogen adsorption and desorption isotherms. The mesoporous ZnO microcube was comprised by many nanoparticles, and inherited the cube shape from [(CH 3 ) 2 NH 2 ][Zn(HCOO) 3 ] precursor. With large surface area and mesoporous structure, the ZnO microcube exhibits excellent photocatalytic activities against methyl orange (MO) and rhodamine B (RhB) under UV irradiation, and the degradation rates reached 99.7% and 98.1% within 120 min, respectively. [ABSTRACT FROM AUTHOR]

As organic dyes are a major group of water pollutants, the development of materials for the removal of dyes is of great significance for the environment. Here, a novel flower-like Fe 3 O 4 @ZIF-67 photocatalyst was synthesized using a simple method at room temperature. It was found that the Fe 3 O 4 @ZIF-67 exhibited the ability of degrading Congo red (CR) quickly under visible light irradiation in a short time after adsorption equilibrium. Free radical trapping experiments revealed that the photo-induced active species superoxide radical (•O 2− ) and holes (h + ) were the predominant active species in the photocatalytic system. In addition, results demonstrated that the Fe 3 O 4 @ZIF-67 can be magnetically recycled, and maintain high photocatalytic activity after reuse over five cycles with no obvious decrease in the removal efficiency. It suggested that the synthesized material had a potentially promising application for CR removal from waste water. [ABSTRACT FROM AUTHOR]

Two new coordination polymers (CPs), namely, [Cu 2 ( ttbz )(H 2 btc) 2 (OH)] n ( 1 ) and [Mn(ttbz) 2 (H 2 O) 2 ] n ( 2 ) ( Httbz =1-(tetrazo-5-yl)-4-(triazo-1-yl)benzene, H 3 btc =1,3,5-benzenetricarboxylic acid), have been hydrothermally synthesized and structurally characterized. Complex 1 exhibits a (3,5,5,5)-connected 2D layer with a Schläfli symbol of {3·4 2 }{3·4 4 0.5 2 0.6 3 }{3 2 0.4 4 0.5 2 0.6 2 }{3 2 0.4 4 0.5 3 0.6}, in which the ttbz - ligand can be described as μ 5 -bridge, linking Cu(II) ions into a 2D layer and H 2 btc - ions play a supporting role in complex 1 . The ttbz - ligand in complex 2 represents the bridging coordination mode, connecting two Mn(II) ions to form the infinite 1D zigzag chains, respectively, which are further connected by two different types of hydrogen bonds to form a 3D supramolecular. Furthermore, catalytic oxidation activities toward organic dyes and electrochemical behaviors of the title complexes have been investigated at room temperature in aqueous solutions, indicating these complexes may be applicable to color removal in a textile wastewater stream and practical applications in areas of electrocatalytic reduction toward nitrite, respectively. [ABSTRACT FROM AUTHOR]

A Cu(II) coordination polymer {[Cu(tmpe) 0.5 (1,2-bdc)]·2CH 3 CN} n (Cu(tmpe)) (tmpe ​= ​1,1,2,2-tetra[4-(2-methyl-1H-imidazole-1-yl)phenyl]ethylene, 1,2-bdc ​= ​1,2-benzenedicarboxylate) was prepared. Cu(tmpe) has the (4,4)-connected 2D structure exhibiting the kgm topology (32·62·72) 2. The series of attached g-C 3 N 4 composites Cu(tmpe)/g-C 3 N 4 were prepared with grinding method and the morphology, functional groups, chemical composition, thermal stability, band gap, optical properties and electrochemical performances of prepared materials were comprehensively characterized with XRD, SEM, HRTEM, EDX, FTIR, XPS, TGA, UV–Vis, PL and electrochemical tests. Cu(tmpe)/10%g-C 3 N 4 had the highest catalytic efficiency for degradation of methylene blue (MB) in a series of Cu(tmpe)/wt%g-C 3 N 4 (w ​= ​5, 10, 15, 20). The photocatalytic study of Cu(tmpe) and its composite Cu(tmpe)/10%g-C 3 N 4 showed high efficiencies of decomposition methylene blue (MB), methyl orange (MO), methyl violet (MV), and rhodamine B (RhB) with the rates were in the order of MB ​> ​MO ​> ​MV ​> ​RhB. Cu(tmpe) and Cu(tmpe)/10%g-C 3 N 4 could degrade 95.4% and 93.6% of MB after 60 ​min and 30 ​min, respectively. The photocatalytic possible mechanism of the degradation process was studied with trapping experiments as well as Mott-Schottky tests. Cu(tmpe) and Cu(tmpe)/10%g-C 3 N 4 composite are good photocatalytic materials for removing organic dye pollutants from wastewater. A 2D Cu(II) coordination polymer Cu(tmpe) and its heterostructural Cu(tmpe)/g-C 3 N 4 composites were prepared and characterized. Cu(tmpe) and Cu(tmpe)/10%g-C 3 N 4 are the good photocatalytic materials. [Display omitted] • A 3D Cu(II) MOF Cu(tmpe) and its heterostructual composite Cu(tmpe)/g-C 3 N 4 were synthesized and characterized. • The degradation rate of MB for Cu(tmpe)/10%g-C 3 N 4 could reach 93.6% within 30 ​min. • The rates for Cu(tmpe)/10%g-C 3 N 4 are 91.9%, 94.2% and 92.8% of MO, MV and RhB within 45, 60 and 75 ​min, respectively. • Cu(tmpe) and Cu(tmpe)/10%g-C 3 N 4 are the good photocatalytic materials. • The.•OH for MB and •O 2 − for MO were the primary active matters. [ABSTRACT FROM AUTHOR]

In this work two new coordination polymers (CPs) with formulas [Zn 2 (Cl)(BTC)(bmb) 2 ] (1) and [Cd 2 (H 2 O) 2 (BTC) 2 ·H 2 bmb·6H 2 O] (2) (bmb=1,4-bis(2-methylimidazol-1-yl)butane and H 3 BTC ​= ​1,3,5-benzenetricarboxylic acid), have been prepared and characterized by various spectroscopic data. The single crystal X-ray data suggests that 1 comprises a 2D layered network and 2 has a 3D porous framework with pcu -type topology. The photocatalytic properties revealed that 2 could successfully degrade organic dyes such as Rhodamine B (Rh B), methylene orange (MO), and methylene blue (MB). Further, the trapping experiment established the active species in the photodegradation process. [Display omitted] • Two new MOFs were synthesized using mixed strategy. • The two MOFs were modulated by synthesized temperature. • Photocatalytic capability was demonstrated for the MOFs. • The photodegradation process was estimated by trapping experiment. [ABSTRACT FROM AUTHOR]

With the development of various industries, the impact of organic dye wastewater discharge on the environment cannot be ignored. Adsorbents and their adsorption properties are the key to the removal of organic dyes from wastewater. In this study, gadolinium metal organic frameworks (Gd-BDC, Gd-BDC-NH 2) were synthesized for the adsorption of anionic dyes in water and exhibited excellent adsorption performance, particularly in Congo red (CR) up to 4592.3 and 5507.1 ​mg ​g−1 at room temperature, respectively. The kinetics simulation showed that the adsorption process was more consistent with the pseudo-second-order model; while the Freundlich model is more suitable to describe the isothermal adsorption process of Gd-MOFs. The electrostatic interaction, π-π stacking and hydrogen bonding between the anionic dye CR and the cationic material Gd-MOFs are the main reasons for the ultra-high adsorption of CR. The excellent adsorption performance on anionic dyes indicates that it is a promising high-performance adsorbent. Gadolinium Metal-organic frameworks (Gd-BDC, Gd-BDC-NH 2) with high adsorption capacity for anionic dyes in water were synthesized in this study. In particularly, the adsorption capacity for Congo red (CR) at room temperature was 4592.3 and 5507.1 ​mg ​g−1, respectively. The excellent adsorption performance indicates that they are promising high-performance adsorbents for CR. [Display omitted] • Gd-BDC and Gd-BDC-NH 2 adsorbents were sucessfully synthesized and showed significant adsorption capacity for anionic dyes, especially Congo red, reaching 4592.3 and 5507.1 ​mg ​g−1 at room temperature, respectively. • Gd-MOFs had a high effect on Congo red removal in a wide pH range (4–10). • Based on FTIR, XPS analyses and references, the reasonable adsorption mechanism of Congo red by Gd-MOFs was deduced. [ABSTRACT FROM AUTHOR]

One 3D Cu(II)-based metal-organic framework {[Cu 3 (tmpa) 2 (1,2,3-btc) 2 (H 2 O) 2 ].14H 2 O.2DMF} n (Cu(tmpa)) (tmpa ​= ​tris(4-(2-methyl-1H-imidazole-1-yl)phenyl)amine, 1,2,3-H 3 btc ​= ​1,2,3-benzenetricarboxylic acid) was prepared by hydrothermal method and characterized. Cu(tmpa) exhibits (3,3,4)-connected 3D topology showing point symbol of (6·8·9) 2 (6·8·10) 2 (62·82·102). The heterostructural Cu(tmpa)/CN composites with different mass proportions were prepared and characterized by XRD, FT-IR, SEM, EDS, UV-DRS, TGA, PL and EIS. The photocatalytic activities of Cu(tmpa) and Cu(tmpa)/20%CN composite to degrade methylene blue (MB), methyl violet (MV), malachite green (MG), and Congo red (CR) were investigated. The photocatalytic degradation of MB by Cu(tmpa)/CN with different mass proportions was studied, and the catalytic conditions catalyst dosage, H 2 O 2 concentration and initial pH value with were optimized. The degradation rate of MB for Cu(tmpa)/20%CN could reach 92.0% within 20 ​min. Cu(tmpa)/20%CN could also degrade 92.0%, 92.9% and 98.2% of MV, MG and CR in 60 ​min, 35 ​min and 3 ​min, respectively. The degradation mechanisms for MB and CR were studied. The enhanced photocatalytic activities of Cu(tmpa)/CN composite might be attributed not only to the vigorous visible-light absorption of Cu(tmpa) , but also to the heterojunction formed by doping g-C 3 N 4 , which accelerates the divorce and movement of photogenerated charges compared to Cu(tmpa). The holes were the primary active matters in the degradation for MB. The holes and superoxide radicals were the main reactive matters in degradation of CR. Cu(tmpa) and Cu(tmpa)/20%CN are good photocatalytic materials. [Display omitted] • A 3D Cu(II) MOF Cu(tmpa) and its heterostructual g-C 3 N 4 composite Cu(tmpa)/CN were synthesized and characterized. • The degradation rate of MB for Cu(tmpa)/20%CN could reach 92.0% within 20 ​min. • Cu(tmpa)/20%CN could degrade 92.0%, 92.9% and 98.2% of MV, MG and CR in 60 ​min, 35 ​min and 3 ​min, respectively. • Cu(tmpa) and Cu(tmpa)/20%CN are the good photocatalytic materials. • The holes were the primary active matters in degradation for MB. [ABSTRACT FROM AUTHOR]

An organic dye as a guest in ferroelectric single crystal can be enhanced the optical, electrical and mechanical properties. The crystal structure of both TGS were estimated by single crystal X-ray diffraction. Hirshfeld surface, voids and fingerprint plot studies were performed to understand the intermolecular interactions of the TGS in graphical representation. The SEM and optical microscope observations of the chemically etched on faces (100) of both TGS crystals were revealed the presence of inverse triangular pyramid pits with dislocation density in order of 103–104 ​cm−2. The high mechanical stability and increased value in Curie temperature with low loss of dielectric permittivity were occurred in dyed TGS. A highly saturated P – E hysteresis loop and higher piezoelectric coefficients were observed in dyed TGS. The improved mechanical strength, dielectric, ferroelectric and piezoelectric properties make the dyed TGS single crystals better candidate for electronic devices. A good quality of TGS single crystal with a pyramid XO dye pattern along (001) and (00 1 ¯) crystallographic planes was grown. Hirshfeld surface and fingerprint of O⋯H interaction in G 2 in TGS crystal. Highly saturated P – E hysteresis, D – V butterfly loops were shown for pure and dyed TGS crystals. [Display omitted] • A pyramidal pattern of XO dye along (001) and (00 1 ¯) crystallographic planes in dyed TGS was observed. • Inverse pyramid etched pits were observed in TGS crystal surface. • T c of dyed TGS was increased ∼4 ​°C due to inclusion of dye. • A highly saturated P – E loop with low polarization relaxation was observed in dyed TGS. • The maximum value of d 22 was observed 127 p.m./V for dyed TGS which is the highest value of TGS crystal family. [ABSTRACT FROM AUTHOR]

Water contamination from organic contaminants like dyes has wreaked havoc on the ecosystem and jeopardized people's health. To this end, in this experiment, the low-crystalline bimetallic MIL-88A Co/Fe-x (Co/Fe-x represents the Co/Fe molar ratio) was synthesized under mild conditions with fumaric acid as ligand, the best performing MIL-88A Co/Fe-2 can completely degrade the MB solution within 20 ​min (100 ​mL, 20 ​mg/L). At lower synthesis temperature, the morphology and coordination structure of MIL-88A(Fe) were greatly changed by the incorporation of Co2+, so that the bimetallic MIL-88A Co/Fe-2 had abundant unsaturated metal sites and oxygen defects. The photoelectrical tests found that the change of structure made the bimetallic MIL-88A Co/Fe-2 have a narrow band gap, photoresponsivity and electron-hole separation efficiency were all improved. Under simulated sunlight, MIL-88A Co/Fe-2 has good universal degradability to a variety of dyes (methyl violet, methyl orange, methylene blue, rhodamine B). In addition, the main active specie of MIL-88A Co/Fe-2 degrading organic dyes was investigated in this experiment, and the possible degradation mechanism was proposed, which provided a feasible idea for the development of efficient photo-Fenton catalysts. In this experiment, bimetallic MIL-88A Co/Fe with low crystallinity and high defects was synthesized by stirring method under mild conditions using fumaric acid as the organic ligand. The best performing MIL-88A Co/Fe-2 has good general degradability to various dyes (methyl violet, methyl orange, methylene blue, rhodamine B). Under mild conditions, the morphology and coordination structure of MIL-88A are greatly changed due to the incorporation of Co2+, which makes the bimetallic MIL-88A Co/Fe-2 rich in unsaturated metal sites and oxygen defects. Photo/electrochemical tests show that this structural change enables the bimetallic MIL-88A Co/Fe-2 to have a narrower band gap, and the photoresponse capability and electron-hole separation efficiency are both improved. [Display omitted] • Using fumaric acid as organic ligand, iron-cobalt bimetallic MIL-88A Co/Fe were prepared under mild conditions. • By reducing the synthesis temperature and introducing Co2+, the bimetallic MIL-88A Co/Fe-2 has a narrow band gap, and the photoresponse ability and electron-hole separation efficiency are improved. • Under simulated sunlight, MIL-88A Co/Fe-2 has good general degradation to various dyes (methyl violet, methyl orange, methylene blue, rhodamine B). [ABSTRACT FROM AUTHOR]

Organic pollutants, particularly nitrogen-rich explosives and carbon-rich dyes are generally degraded by different photocatalysts under either visible or ultraviolet light, leading to substantial waste and cost. Three photocatalysts with Z-scheme structures, Ag@AgBr/Cu 2 O-1, Ag@AgBr/Cu 2 O-2, and Ag@AgBr/Cu 2 O-3, are designed and synthesized employing a simple solvothermal and photoreduction technique to develop advanced photocatalyst materials that can degrade nitro substances under ultraviolet (UV) irradiation and organic dyes under visible-light irradiation. The structural characterization of Ag@AgBr/Cu 2 O-2 as determined through various spectroscopic techniques (e.g. XPS, XRD and TEM) reveal that the Z-scheme photocatalysts are composed of Ag, Cu 2 O and AgBr nanospheres with particle size less than 100 ​nm, while nano-Ag and nano-AgBr coupled to the surface of the Cu 2 O microspheres. Further investigations demonstrate that these photocatalysts exhibit a good UV–visible absorption range (200–800 ​nm) and outstanding photocatalytic degradation activity for two typical organic pollutants. Among them, Ag@AgBr/Cu 2 O-2 achieve a 100% degradation of trinitrotoluene (a common explosive) in 30 ​min under UV radiation, and a 99.2% degradation of rhodamine B (a typical dye) in 60 ​min under visible-light irradiation in the absence of UV light, demonstrating remarkable dual-band adaptability. Moreover, Ag@AgBr/Cu 2 O-2 displays superior stability, with a degradation rate of up to 85% after four cycles. The putative photocatalytic reaction mechanism is proposed based on the radical trapping experiment. [Display omitted] • The newly reported Z-scheme photocatalysts Ag@AgBr/Cu 2 O show good light absorption over the UV–visible range (200–800 ​nm). • These Z-scheme photocatalyst can degrade different organic pollutants under ultraviolet and visible-light irradiation. • The new Z-scheme photocatalyst can degrade at least 99% of trinitrotoluene and rhodamine B within 1 ​h in the UV–visible-light irradiation. • The reaction rate constant of Ag@AgBr/Cu 2 O-2 is 1.38 times that of Ag@AgBr and 74 times that of Cu 2 O. [ABSTRACT FROM AUTHOR]

At present, a large number of pathogenic microorganisms and organic dyes pollute water resources and have an impact on human health. Photocatalysis is a promising method for sterilization and degradation. But research on the effective use of sunlight for photocatalytic inactivation of bacteria is limited. Sea urchin-like WO 3-x was synthesized by hydrothermal method. Ag nanoparticles (Ag NPs) supported on WO 3-x nanospheres were prepared by the photoreduction method to obtain Ag/WO 3-x composites, and the reduction time could control the loading amount. The relevant properties of the material were characterized in detail. The photodegradation of Rhodamine B (Rhb) by WO 3-x and Ag/WO 3-x was carried out under simulated sunlight. The results shown that the photocatalytic degradation rate of Ag/WO 3-x was about 69%, which was about twice that of WO 3-x. The bactericidal activity of WO 3-x and Ag/WO 3-x against Escherichia coli(E.coli) and Staphylococcus aureus(S. aureus) was investigated. The synthesized Ag/WO 3-x composites exhibited more than 97% bactericidal rate against both model bacteria under 2 ​h of light irradiation. The excellent photocatalytic degradation and bactericidal properties of Ag/WO 3-x composites were due to the enhanced photocatalytic performance of the composites after WO 3-x loaded with Ag NPs. Sea urchin-like WO 3-x and Ag/WO 3-x were synthesized by a hydrothermal method. The results showed that the photocatalytic performance of WO 3-x was improved after loading with Ag NPs. Ag/WO 3-x have the potential to be used as photocatalysts to treat wastewater containing organic dyes and pathogenic microorganisms. [Display omitted] • Sea urchin-like WO 3-x and Ag NPs-loaded WO 3-x were synthesized by hydrothermal method. • Photocatalytic degradation and sterilization of Ag/WO 3-x were investigated. • Ag/WO 3-x has excellent photocatalytic degradation and bactericidal properties. [ABSTRACT FROM AUTHOR]

Fabricating host-guest composites based on the combination of porous metal-organic frameworks (MOFs) and fluorescent dyes is appealing for ratiometric luminescent thermometry. Herein, we design a NbO-type MOF, which has a 3D architecture established by a tetracarboxylic ligand containing π-conjugated naphthalene moiety and Zn2+ ions via solvothermal conditions. The considerable regular channels enable the guest molecules Rhodamine B (RhB) to be quickly absorbed. The composite RhB@MOF formed by ion-exchange was further explored the temperature sensing behavior in the physiological temperature range. RhB@MOF exhibits an excellent linear relationship between the luminescent intensity ratio of the organic linker and the dye RhB and temperature in the range of 30–90 ​°C, with the maximum relative temperature sensitivity (S r) of 0.42%·oC−1 at 30 ​°C. These results validate the potential of this thermal-responsive material for sensitive temperature detection and further promote the development of ratiometric thermometers working in the physiological temperature range. The dual-emitting composite RhB@ZnNDPA was constructed by embedding Rhodamine B in the NbO-type MOF ZnNDPA, which exhibits high stability and excellent temperature sensing behavior in the physiological temperature range. [Display omitted] • A NbO-type MOF ZnNDPA was synthesized using the naphthalene-containing tetracarboxylate ligand. • Rhodamine B was adsorbed into the pores of ZnNPDA to construct the dual-emitting dye@MOF composite. • RhB@ZnNDPA features high stability and excellent linear luminescence response to temperature in the range 303–363 ​K. [ABSTRACT FROM AUTHOR]

A Cu(I)-MOF, namely {[Cu(4-PTZ)]·(H 2 O) 0.5 } n (1), that contains rhombic channels with the size of 10.174 ​Å ​× ​16.965 ​Å has been obtained based on in situ generated 5-(4-pyridyl)-1H-tetrazole ligand. Compound 1 not only displays remarkable capability for selective adsorption toward the organic dye Methylene Blue (149.5 ​mg ​g−1), but also shows reversible adsorption of I 2 molecules in hexane medium (96.2%). Therefore, compound 1 should be a promising MOF-based bifunctional adsorbent in the field of pollutant removal. A Cu(I)-MOF based on in situ genersated 5-(4-pyridyl)-1H-tetrazole ligand was synthesized successfully by a facile one-pot method. It contains rhombic channels with the size of 10.174 ​Å ​× ​16.965 ​Å and uncoordinated N sites. Compound 1 not only displays remarkable capability for selective adsorption toward the Methylene Blue, but also shows reversible adsorption of I 2 molecules in hexane medium. [Display omitted] • Compound 1 was synthesized successfully by a facile one-pot method. • Compound 1 could selectively removal MB dye molecule from aqueous solution. • Compound 1 shows reversible adsorption of I 2 molecules in hexane medium. [ABSTRACT FROM AUTHOR]

A porphyrin-based two-dimensional covalent organic framework (TPE-Por-COF) with high stability was synthesized, and the adsorption performance of TPE-Por-COF on organic dyes was studied. The TPE-Por-COF was characterized by X-ray powder diffraction, infrared spectroscopy, solid-state nuclear magnetic resonance, thermogravimetry and N 2 adsorption isotherms. TPE-Por-COF has adsorption effect on five dyes: malachite green (MG), methyl violet (MV) and rhodamine B (RhB), coomassie brilliant blue (CBB) and brilliant green (BG). Among them, TPE-Por-COF has the most obvious adsorption effect on malachite green, and the adsorption capacity is as high as 1428.57 ​mg ​g-1. In addition, the CO 2 adsorption capacity of TPE-Por-COF is 187 ​mg ​g-1 at 50 ​bar and 323 ​K. A new COF (TPE-Por-COF) based on porphyrin and tetraphenylethylene derivatives was synthesized, which can be used as effective dye adsorption and gas storage. TPE-Por-COF has an adsorption effect on five dyes: malachite green (MG), methyl violet (MV) and rhodamine B (RhB); coomassie brilliant blue (CBB) and brilliant green (BG). Among them, TPE-Por-COF has the most obvious adsorption effect on malachite green, and the adsorption capacity is as high as 1428.57 ​mg ​g-1, and the adsorption rate is 15.9 ​mg ​g-1 min-1 in the first minute. For each dye, the dye adsorption effect of TPE-Por-COF did not decrease significantly within 5 cycles. In addition, the adsorption capacity of TPE-Por-COF for CO 2 was 187 ​mg ​g-1 at 50 ​bar and 323 ​K. [Display omitted] • A new covalent organic framework adsorbent based on porphyrin and tetraphenylethylene derivatives was synthesized. • The adsorbent has excellent adsorption performance for MG, MV, RhB, CBB, and BG dyes. • The adsorption kinetics and isotherms were studied in detail. • The adsorbent has a good carbon dioxide adsorption capacity. [ABSTRACT FROM AUTHOR]

Two polymorphic Cu-based coordination polymers (CPs) based on the ligand 1,2,4-benzenetricarboxylic acid (H 3 BTC) have been prepared via solvothermal synthesis. Each of these CPs (denoted as 1 and 2) possessed the same formula [Cu(1,2,4-H 2 BTC) 2 ]·4H 2 O but they each exhibited a distinct crystalline phase. These CPs were structurally characterized via elemental analyses, Fourier-transform infrared (FT-IR) spectroscopy, powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA) and single crystal X-ray diffraction techniques. The title CPs display versatile structural features with 1D and 2D frameworks. Complex 1 exhibits a 2D layer, and two carboxyl groups belonging to the 1,2,4-H 2 BTC anion are deprotonated, which link the Cu(II) ions together to generate a 2D sheet. Meanwhile, complex 2 consists of a 1D chain with different coordination modes from that of 1. The influence of the aromatic polycarboxylic ligand on the structures of Cu-based complexes is discussed herein. On this basis, a 2D carbon-coated copper nanoparticle composite (Cu@C) was prepared by using the 1D Cu-based CP as a precursor. Furthermore, the selective adsorption and photocatalytic properties of Cu@C have also been investigated in detail. Two polymorphic Cu-based CPs based on 1,2,4-H 3 BTC by adjusting the ratio of organic ligands with the same formula have been synthesized and characterized. The influence of aromatic polycarboxylic ligand on the structures of Cu-based complexes has been discussed. Moreover, a 2D carbon-coated copper nanoparticle composite (Cu@C) was prepared by using the 1D Cu-CP as a precursor. Furthermore, the selective adsorption and photocatalytic properties of Cu@C have also been investigated in detail. [Display omitted] • Two polymorphic Cu-based CPs constructed with 1,2,4-H 3 BTC were synthesized. • The effect of aromatic polycarboxylic ligand on Cu-CPs had been investigated in detail. • The two CPs have high stabilities in various organic solvents. • The as-grown Cu@C was synthesized from the precursor of complex 2 by the CVD method. • The as-grown Cu@C exhibited selective adsorption and photocatalytic properties toward CR. [ABSTRACT FROM AUTHOR]

A microporous indium-based metal-organic frameworks (MOFs), namely [(CH 3) 2 NH 2 ] 2 [In 2 (H 3 L) 2 (OX)]·3DMF·2H 2 O (JOU-23) (H 3 L ​= ​terphenyl-3, 4′, 5-tricarboxylic acid; OX ​= ​oxalic acid), have been solvothermal synthesized and characterized. Single-crystal X-ray diffraction show that JOU-23 displays three-dimensional anionic framework with 2-fold interpenetrated nets and rare topology. Due to its anionic and porous framework, JOU-23 can be developed for effective absorbing and separating cationic organic dyes. Further studies reveal that both the charge and size of dye molecules would affect the dyes' absorption and separation. In addition, JOU-23 dispersed in dimethyl formamide shows strong emission at about 364 ​nm. Thus, it was developed as an efficient fluorescent sensor for probing Fe3+ ions and nitroaromatic compounds. The detection limit of Fe3+ is as low as 2 ​× ​10−6 ​M (K SV ​= ​59,755 ​M−1), which is excellent in MOFs fluorescent probe. At the same time, JOU-23 shows widespread sensing performance to nitroaromatic compounds. Especially, the detection ability of JOU-23 for nitrobenzene (NB) is good. Although the NB concentration reaches only 4.175 ​× ​10−5 ​M, the quenching efficiency can achieve 86.4%. Further studies show that the quenching performance of JOU-23 is mainly attributed to the competition of excitation light absorption and the absorption of emission light by measured objects. These results indicate that JOU-23 can be applied as a multifunctional material for organic dyes adsorption/separation, Fe3+ ions detection, and nitroaromatic compounds sensing. A microporous anionic 2-fold interpenetrated In(III)-MOF has been synthesized and developed as multifunctional materials for organic dyes adsorption/separation and fluorescent sensitization of Fe3+ ions and nitroaromatic compounds. [Display omitted] • A microporous In-MOF with 2-fold interpenetrated anionic framework has been solvothermal synthesized. • JOU-23 represents a rare (3,6)-connected topology with the Schläfli symbol of (4·62) 2 (42·610·83). • JOU-23 can selective absorption and chromatographic separation of cationic dyes. • JOU-23 has been utilized as an efficient fluorescence "turn-off" sensor for probing Fe3+ ions and nitroaromatic molecules. [ABSTRACT FROM AUTHOR]

In this work, we proposed a green and low-cost method to prepare novel waste cellulose/ZIF-67 composite aerogels as the adsorbent. These composites were fabricated by assembling ZIF-67 crystals into the three-dimension framework of cellulose aerogel derived from waste cigarettes. Due to the high specific surface area and electrostatic attraction, as-prepared waste cellulose/ZIF-67 aerogels had a high adsorption capacity for anionic dyes. The methyl orange was selectively adsorbed by waste cellulose/ZIF-67 compared to methyl blue. The maximum adsorption capacity for methyl orange reached to 134.36 ​mg ​g−1. Interestingly, this adsorption capacity can maintain above 80% after 5 cycles. Thus, as-prepared waste cellulose/ZIF-67 aerogels in this paper have an important potential application in waste water treatment as a selective adsorbent. The zeolitic imidazolate framworks-67 (ZIF-67) decorated waste cellulose aerogels are fabricated by a facile blending method using waste cigarette filters and NaOH/urea as cellulose resources and a green solvent, respectively. The as-prepared samples exhibit effective selective adsorption behavior of methyl orange. [Display omitted] • The waste cigarette filters were used as cellulose resources. • The specific surface area of WCA/ZIF-67 aerogel is high up to 825 ​m2 ​g−1. • The WCA/ZIF-67 aerogel shows an excellent selective adsorption capacity for anion dyes. • The WCA/ZIF-67 aerogel has superior reusability. [ABSTRACT FROM AUTHOR]

Abstract: Electrospun copper based composite nanofibers were synthesized using the copper acetate/polyvinyl alcohol/water solution as starting material. Synthesized composite nanofibers were sintered at 500°C to obtain CuO nanofibers. XRD, FTIR and XPS techniques were used to confirm the presence of pure CuO nanostructures. The effect of annealing cycle on the crystalline structure of the CuO nanofibers was analyzed and observed that the decrease in crystallite size with an increase in the dwelling time improved the orientation of the CuO crystallite. The blue-shift in the band-gap energies of CuO nanofibers was observed as a result of quantum confinement from bulk CuO (1.2eV) to one dimensional (1D) nanostructures (∼1.746eV). The catalytic activity of the CuO fibers for the degradation of methyl orange was carried out and as a blocking layer in ZnO based DSSC was fabricated and observed a ∼25% increase in the current density. [Copyright &y& Elsevier]

Zeolitic imidazolate framework ZIF-67 with a pore-structural network has many potential applications in photocatalysis fields due to their intrinsic properties such as high porosity and large surface area. ZIF-67 is prepared under a one-step hydrothermal reaction from cobalt salt in methanol. The morphological and photocatalytic characteristics of ZIF-67 are performed by XRD, SEM, UV–Vis, PL spectroscopy, and BET. The as-synthesized nanoparticles have a nearly monodisperse structure with a large size of ~600 ​nm. In addition, these ZIF-67 micropores show an excellent efficiency for the methyl orange (MO) photodegradation under visible-light irradiation. In particular, more than 88% of MO is degraded within 1 ​h when using 0.5 ​g ​L−1 of ZIF-67. Besides, the photocatalytic and kinetic performances of ZIF-67 are investigated by optimizing pH value, initial MO concentration in solution, and initial dose of used catalyst. ZIF-67 nanocrystals are demonstrated to be a remarkable material with high photostability and easy reusability. 3D zeolitic imidazolate framework cobalt-derived ZIF-67 is well-known to be a potential pore-structural material, resulting in no large-particle-sized nuclei in nitrate salts by Hofmeister anion effect. Surprisingly, the as-synthetic nanocrystals gained nearly monodisperse structure with a large size for the efficient photodegradation of organic dyes under visible-light conditions. ZIF-67, high photostability and easy reusability, worked quite effectively in a wide pH range.". [Display omitted] • ZIF-67 exhibited an effective photocatalytic performance under visible light with photostability and reusability. • Approximately 88% of the MO concentration was degraded within 1 ​h by using 0.5 ​g ​L−1 of ZIF-67. • MO photodegradation followed pseudo-first-order kinetics with a rate constant k of 0.036 min−1. • ZIF-67 worked quite effectively in a wide pH range (3 to 11). [ABSTRACT FROM AUTHOR]

In this paper, a new composite aerogel egg yolk/zeolitic imidazolate framework-8/crosslinked polyacrylic acid (EY/ZIF-8/CLPAA) was prepared by in situ polymerization of acrylic acid in composite system of egg yolk and ZIF-8. The structure and performance of the composite aerogel were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), in-situ attenuated total reflection Fourier transform infrared spectrometer (FT-IR) and comprehensive thermal analyzer (TG). The results show that the composite aerogel has irregular porous structure inside, and ZIF-8 has 12-sided crystal structure. The composite aerogel has good thermal stability and water stability and can effectively remove dyes in wastewater. It has different equilibrium adsorption capacity for different dyes: Malachite Green: 2338 ​mg/g, Crystal Violet: 489 ​mg/g, Methyl Orange: 447 ​mg/g and Rhodamine B: 299 ​mg/g. The adsorbent still maintains a certain activity after five adsorption-desorption cycles. The EY/ZIF-8/CLPAA aerogel adsorbs organic dyes mainly through electrostatic interaction, π-π interaction and hydrogen bonding. The adsorption data conforms to the pseudo-second-order kinetic model and follows the Langmuir adsorption isotherm. The egg yolk/zeolitic imidazolate framework-8/crosslinked polyacrylic acid (EY/ZIF-8/CLPAA) was prepared by in situ polymerization of acrylic acid in composite system of egg yolk and ZIF-8. It has different equilibrium adsorption capacity for different dyes: Malachite Green: 2338 ​mg/g, Crystal Violet: 489 ​mg/g, Methyl Orange: 447 ​mg/g and Rhodamine B: 299 ​mg/g. [Display omitted] • The egg yolk/zeolitic imidazolate framework-8/crosslinked polyacrylic acid aerogel (EY/ZIF-8/CLPAA) was prepared by in situ polymerization of acrylic acid in composite system of egg yolk and ZIF-8. • The composite aerogel (EY/ZIF-8/CLPAA) improve the adsorption performance of biomass materials, enhance the structural strength of aerogel materials and overcome the shortcomings of difficult recovery of ZIF-8 in the adsorption process. • The composite aerogel (EY/ZIF-8/CLPAA) has good thermal stability and water stability. • The abundance functional groups provide more active sites for adsorption of organic dye molecules. The adsorption capacity of EY/ZIF-8/CLPAA aerogel for Malachite Green (MG): 2338.7 ​mg/g. The removal rate of MG can reach 96.9%. [ABSTRACT FROM AUTHOR]

A new coordination polymeric chains modified polyoxometalate, H 3 K 2 [Ag 5 (DTB) 5 [SiW 12 O 40 2 ·Cl 2 ·8H 2 O (1) {DTB ​= ​1,4-di(1H-1,2,4-triazol-1-yl)benzene}, has been successfully synthesized under hydrothermal conditions. Single crystal X-ray diffraction analyses reveal that the Keggin POM cluster is modified by {Ag(DTB)} n chains in an unusually [2 ​+ ​4] asymmetrical mode resulting in a 2D double layer structure. By connection of K cations and π···π interactions between adjacent {Ag(DTB)} n coordination polymeric chains, the 2D structure extends to a 3D structure. In addition, crystal 1 can be used as a packing material for the highly selective adsorption and separation cationic dyes such as methylene blue (MB) and crystal violet (CV) against with methyl orange (MO) anionic dyes. The adsorption of a series of cationic organic dyes experiment demonstrated that this process is highly related to the sizes of organic dyes. A new coordination polymeric chains modified polyoxometalates with rare [2+4] asymmetrical mode has been isolated under hydrothermal conditions. Obtained compound can be used as a packing material for the highly selective adsorption and separation cationic dyes such as methylene blue (MB) and crystal violet (CV) against with methyl orange (MO) anionic dyes. Image 1 • A new coordination polymeric chains modified polyoxometalates was synthesized. • Title compound represents an unusually example of [2 ​+ ​4] asymmetrical mode based on {Ag(DTB)} n chains. • Title compound could act as stationary phase to selectively adsorb cationic dyes over anionic dye. [ABSTRACT FROM AUTHOR]

Two Zr-based metal-organic cages (Zr-MOCs) were synthesized under solvothermal conditions. Directed by the solvent system, two Zr-MOCs that built from the same trinuclear zirconocene unit and 2,6-naphthalenedicarboxylic ligand (2,6-H 2 NDC) exhibit different geometry configurations. Zr-MOC-1 presents a tetrahedral cage structure, while Zr-MOC-2 features a capsule-like cage skeleton. The adsorption performances of Zr-MOCs for organic dyes from aqueous solution were first reported, which indicates that two Zr-MOCs show good adsorption behaviors for anionic and cationic dyes. Two Zr-based metal-organic cages(Zr-MOCs) were isolated by solvent-directed construction. Their adsorption performances for organic dyes were explored in water.As a result, it's rarely observed that anionic and cationic dyes can be both adsorbed. Image 1 • The current study is to introduce the solvent-directed assembly of two Zr-based metal-organic cages (Zr-MOCs). • The adsorption performances of Zr-MOCs for organic dyes from aqueous solution were first reported. • It's rarely observed that anionic and cationic dyes can be both adsorbed. • To display the application of Zr-MOCs as adsorbent for the removal of organic pollutants. [ABSTRACT FROM AUTHOR]

In the present investigation, the applicability of the adsorption and removal of the toxic organic dye Congo red (CR) from industrial wastewater using metal organic framework (MOFs) Fe 3 O(OH 2) 3 Cl(NH 2 -BDC) 3 ·9.5H 2 O (Fe-MIL-88NH 2) was evaluated. The influence of contact time, initial CR concentration, adsorbent dosage, ionic strength and temperature on the adsorption properties of Fe-MIL-88NH 2 were investigated. The Langmuir and Freundlich and Tempkin isotherm models have been used to discuss the adsorption behavior of CR on Fe-MIL-88NH 2. Tempkin adsorption isotherm model was found to be most suitable for the adsorption of CR. Different kinetic parameters were obtained by studying of adsorption kinetics on the basis of the pseudo-first-order, pseudo-second-order and intraparticle diffusion kinetic equations. The pseudo-second-order kinetic equations is most suitable for adsorption of CR on Fe-MIL-88NH 2 , which indicates that the removal of CR are mainly carried out by chemical adsorption process. With excellent adsorption performance, Fe-MIL-88NH2 has a good application prospect in the aspect of removing of Congo red from wastewater. Fe-MIL-88NH2 with the morphology of spindle structure was prepared solvothermal method. Congo red is mainly removed from wastewater through chemisorptions by using the Fe-MIL-88NH2 as adsorbent. The adsorption of Congo red on Fe-MIL-88-NH2 is an endothermic process. Image 1 • Fe-MIL-88-NH 2 is a promising adsorbent for removing of organic pollutant Congo red from wastewater. • The main adsorption sites of Fe-MIL-88NH 2 are on its heterogeneous surface. • Congo red is mainly removed from wastewater through chemisorptions by using the Fe-MIL-88NH 2 as adsorbent. • The adsorption of Congo red on Fe-MIL-88-NH 2 is a spontaneous endothermic process. [ABSTRACT FROM AUTHOR]

Heterogeneous photocatalytic degradation of organic dyes has attracted tremendous attention due to be economical and environmentally friendly. We present herein a tetracarboxyate photocatalyst (Mgtptc) based on MgO 6 octahedral. With increased particle size of Mgtptc , the PL intensity displayed a quenching effect as well as a lengthened emission lifetime, which might contribute to photoinduced electron−hole pairs separation. Mgtptc at the particle size of 0.45–0.30 ​μm showed highly photocatalytic activity in degradation of cation and neutral dyes upon UV light exposure. Based on the reactive species capturing, the responsible photocatalytic mechanism was discussed in detail. Furthermore, degradation efficiency of MB was not of significant loss after five consecutive cycles, suggesting its excellent photostability. A tetracarboxyate photocatalyst based on MgO6 octahedra, with its increased particle size, displayed a quenching effect as well as the lengthened emission lifetime. It might contribute to photoinduced electron−hole pairs' separation. Image 1 • A heterogeneous catalyst (Mgtptc) of excellent photostability and environmental friendliness is proposed. • The PL intensities of Mgtptc displays a quenching effect with its increasing particle size. • Mgtptc displays its highly selective photoactivity for cation and neutral dyes upon UV light irradiation. • A mechanism is proposed to rationalize the complete mineralization. [ABSTRACT FROM AUTHOR]

In this study, we have synthesized six new coordination polymers (CPs), namely {[Cu 6 (3,5-bip) 6 (H 2 O) 12 (SO 4) 6 ]·3H 2 O} n (1), [Co(3,5-bip) (H 2 O) 3 (SO 4)] n (2), {[Cu(1,3-bit) 2 (H 2 O) 2 ]·2(NO 3)} n (3), {[Cu 2 (1,3-bit) 2 (1,3-bcbb) 2 ]·4(H 2 O)} n (4), [Cu(4,4′-bibp) (H 2 O) (NO 3) 2 ] n (5), [Cu(4,4′-bibp) (4,4′-Hsbdc)] n (6) via solvothermal methods. The structures of these new CPs have been characterized by elemental analysis, FTIR, TG analysis, PXRD and single crystal X-ray diffraction techniques. Meanwhile, the title CPs are explored for adsorption of organic dyes, i.e., anionic dyes (congo red (CR), and methyl orange (MO)) and cationic dye (methylene blue (MB)) considered extensively as water colorants pollutants. Worth noting, complex 3 can adsorb anionic dyes (CR and MO) quickly; complex 6 shows great performance in CR adsorption. Kinetic study reveals that the adsorption process is performed via pseudo-second-order reaction. The dye removal investigations of complexes 3 and 6 support that ions exchange and H-bonding interactions between CPs and target organic dyes are significant factors, heavily affecting dye adsorption. They have excellent potential in wastewater treatment. The first author and corresponding authors made the greatest contribution to this article, while the other authors contributed similarly. Image 1 • Six new coordination polymers (CPs) have been hydrothermally prepared and characterized. • Complexes 3 could selectively adsorbs anionic dyes (CR and MO) quickly from aqueous solution with good repeat-ability. • Complex 6 shows great dye adsorption performance for CR with good repeat-ability in aqueous system. • This work highlights the advantages of 2D CPs as excellent hazardous dye adsorbents. [ABSTRACT FROM AUTHOR]

The egg white@zeolitic imidazolate framework-8@polyacrylic acid (EW@ZIF-8@PAA) aerogel was prepared by using in-situ polymerization of acrylic acid and freezing and freeze drying, with egg white and ZIF-8 as raw materials and 1, 4-butanediol as crosslinking agent. The aerogel possess irregular porous structure and exhibits good stability in water. The aerogel applied in the adsorption of organic dyes shows the adsorption for malachite green (MG), crystal violet (CV), methyl orange (MO) and rhodamine B (RB), which has excellent adsorption capacity for malachite green, and the maximum adsorption capacity is 2764.9 ​mg/g. The kinetic data of four dyes all conform to the pseudo-second-order kinetic model and the Langmuir adsorption isotherm. The adsorbent still has a certain activity after five adsorption-desorption cycles. The egg white@zeolitic imidazolate framework-8@polyacrylic acid (EW@ZIF-8@PAA) aerogel was first synthesized by in-situ polymerization of acrylic acid with egg white and ZIF-8 as raw materials and 1, 4-butanediol as crosslinking agent. The aerogel have showed excellent adsorption capacity for malachite green, and the maximum adsorption capacity is 2764.9 ​mg/g. Image 1 [ABSTRACT FROM AUTHOR]

The present study, highlights essentially a phenomenon rarely encountered in NiFe 2 O 4 nanoparticles self-assembled in the presence of organic azo dye (i.e. Methyl orange). To the best of our knowledge, NiFe 2 O 4 nanoparticles with fibrous morphology is unprecedent. Unexpected features of solid-state morphology changes from zero-dimensional to quasi one-dimensional and back again were evaluated by applying a wide range of complementary physico-chemical characterization techniques to unequivocally assess the nature of the self-assembly process. Scanning electron microscopy reveals the reversibility of the above-mentioned process, under various applied conditions. Zero-dimensional nickel ferrite nanoparticles (as-synthesized) are assembled into quasi one-dimensional fibers, uniformly distributed in all three directions by adsorption of Methyl orange (MO) dye, with texture preserved after the photocatalytic process, and finally it returns to the initial appearance (zero dimensional) by applying a thermal treatment. The presented results may contribute to photocatalyst development by in/ex-situ tuning the morphology of the material, which allows active sites to spread over a wide internal surfaces and pores which, in turn, enhance the photodegradation ability of the catalyst. Materials at nanoscale level with morphology-controlled features are of great interest and significance for the design and photocatalyst development. In the present study, based on the experimental data, a possible formation mechanism of unprecedent solid nanofibers of nickel ferrite is proposed. Zero-dimensional nickel ferrite nanoparticles are assembled into nanofibers uniformly distributed in all three directions. Image 1 [ABSTRACT FROM AUTHOR]

Two new coordination polymers, namely, [Zn 2 (ctpy) 2 (bdc)] n (1) and [Zn(ctpy)(suc) 0.5 n (2) (Hctpy ​= ​2,2':6'2"-terpyridine-4'-carboxylic acid, H 2 bdc ​= ​1,4-benzene dicarboxylic acid, H 2 suc ​= ​succinic acid) have been synthesized under solvothermal condition. Structural analysis reveals that complexes 1 and 2 exhibit 1D ladder chain structures formed with the coordinated Zn(II) and Hctpy as ladder chains and the coordinated H 2 bdc/H 2 suc as the bars. The neighbouring chains are further linked by π ... π packing to form 2D layer structures. Both the two complexes show highly selective detection of 2,4,6-trinitrophenol, 2,4-dinitrophenol, 4-nitrophenol and 2-nitrophenol from benzene based nitroaromatics (NACs), and efficient removal of Congo Red (CR) from aqueous solution. Two new bifunctional coordination polymers, namely, [Zn 2 (ctpy) 2 (bdc)] n (1) and [Zn(ctpy)(suc) 0.5 n (2) (Hctpy ​= ​2,2':6'2"-terpyridine-4'-carboxylic acid, H 2 bdc ​= ​1,4-benzene dicarboxylic acid, H 2 suc ​= ​succinic acid) have been synthesized successfully. Both the two complexes show highly selective detection of phenol based nitroaromatics (NACs) and efficient removal of Congo Red (CR) from aqueous solution. Image 1 • Two new bifunctional coordination polymers were synthesized successfully. • Complexes 1 and 2 show highly selective detection of phenol based nitroaromatics (NACs). • Complexes 1 and 2 show efficient removal of Congo Red (CR) from aqueous solution. [ABSTRACT FROM AUTHOR]

A novel cobalt(II) metal-organic framework, formulated as {[Co 3 (NTB) 2 (DPE)(DMF)]}·7H 2 O·3DMF (1) (NTB ​= ​4,4ˊ,4ˊˊ-nitrilotrisbenzoic, DPE ​= ​1,2-di(4-pyridyl)ethane, DMF ​= ​N,N-dimethylformamide) has been successfully synthesized via solvothermal conditions. This metal-organic framework (MOF) has a three-dimensional (3D) net with 2-fold interpenetration. It can be acted as a heterogenous catalyst to activate peroxymonosulfate (PMS) to generate sulfate radicals (SO 4 •−) to degrade organic dyes in water, such as Rhodamine B (RhB), Methyl orange (MO) and Methylene blue (MB) with the degradation efficiency is all above 93%. For RhB degradation, the possible mechanism and factors affecting the PMS activation were investigated in detail. Additionally, 1 also exhibits excellent chemical stability and stable catalytic activity. A novel cobalt(II) MOF with 2-fold interpenetration structure was synthesized. 1 can be acted as a heterogenous catalyst to activate peroxymonosulfate (PMS) to generate sulfate radicals (SO 4 •−) to degrade organic dyes in water, such as Rhodamine B (RhB), Methyl orange (MO) and Methylene blue (MB) with the degradation efficiency is all above 90%. Image 1 • A novel Co-based MOF (1) has a 3D 2-fold interpenetration net with high thermal stability. • The results reveal that 1 has excellent chemical stability in acid/base solution (pH ​= ​3 and pH ​= ​11) and water (100 ​°C). • 1 acts as a new efficient heterogenous catalyst to degrade organic dyes with the degradation efficiency is all above 93%. • The proposed mechanism was investigated. [ABSTRACT FROM AUTHOR]

Three novel Zn(II)-based coordination polymers (Zn-CPs), namely {[Zn(1,3,5-tib) 2 (H 2 O) 2 ·2(NO 3)} n (1), [Zn(1,3,5-tib)(4,4′-saba)] n (2), and {[Zn(1,3-bit)(4,4′-cpmb)]·0.5(1,3-bit)} n (3), have been hydrothermally synthesized and successfully characterized by single crystal X-ray diffraction (1,3,5-tib ​= ​1,3,5-tris(1-imidazolyl)benzene), 4,4′-Hsaba ​= ​4-(4-sulfoacid)-benzoic acid, 1,3-bit ​= ​1,3-bis(l-imidazoly)toluene, and 4,4′-H 2 cpmb ​= ​4-(4-carboxylphenylmethylthio)benzoic acid). Structural analysis reveals that complex 1 manifests a 2D planar structure with an unprecedented (2,4)-c topological network. Complex 2 and complex 3 display a 3-c fes and 6-fold classical Ia interpenetrated dia framework with 4-c (66) sqc6 topology framework, respectively. Among the three complexes, CPs 1 and 2 demonstrate excellent performance for Azo organic dyes' adsorption, for which the selectivity and kinetics have been comprehensively studied. CPs 3 shows great luminescent intensity in aqueous solution. It is further applied as a fluorescence sensor to detect Fe3+ cation, Cr 2 O 7 2− anion, and tetracycline antibiotic. Three Zn(II) coordination polymers (Zn-CPs), {[Zn(1,3,5-tib) 2 (H 2 O) 2 ·2(NO 3)} n (1), [Zn(1,3,5-tib)(4,4′-saba)] n (2), and {[Zn(1,3-bit)(4,4′-cpmb)]·0.5(1,3-bit)} n (3), have been hydrothermally prepared. While 1 – 2 could be applied as a CR dye adsorbent, and 3 could be as a potential sensing material for detection of Fe3+, Cr 2 O 7 2−, and TC. Image 1 • Three new Zn (II) coordination polymers (Zn-CPs) have been hydrothermally prepared and characterized. • Complexes 1 – 2 could selectively removal CR dye molecule from aqueous solution. • Complex 3 could be used to detect Fe3+, Cr 2 O 7 2−, and TC with high selectivity, anti-interference, and repeat-ability. [ABSTRACT FROM AUTHOR]

The treatment of dyeing wastewater has been a major issue of environmental pollution at present. Adsorption is one of the more feasible methods, Metal-organic frameworks (MOFs) as a class of emerging porous materials have been widely utilized in adsorptive removal of organic dyes. Herein, we designed and synthesized a Cd-MOF {[Cd 2 (BPTC)(H 2 O) 6 ·2H 2 O} n (H 4 BPTC ​= ​3,3′,5,5′-biphenyl tetracarboxylic acid) to investigate the correlation of size-exclusion and charge-matching effect between MOFs adsorbents and dye molecules. X-ray single crystal diffraction indicated that Cd-MOF exhibits a unique double-layered helical coordination framework with tetramer water moieties accommodated in the open channels. Zeta-potential of Cd-MOF revealed it a negative charged framework that preferred electrostatic interactions with cationic dye particles, which endorsed Cd-MOF good adsorption capacities to cationic dyes especially methylene blue (MB) with the highest adsorption capacity of 595.4 ​mg ​g–1 at pH ​= ​7. A double-layered structural Cd-MOF was synthesized to selectively uptake cationic and neutral dyes. The lowest Zeta potential of Cd-MOF at pH ​= ​7 led to the highest removal percentage and adsorption amount of MB because of the strong electrostatic interactions between MB cations and negative charged surface of neutral Cd-MOF. Image 1 • A Cd-MOF was synthesized showing a unique double-layered helical coordination network accommodating water tetramers. • Cd-MOF preferred to electrostatic interactions with cationic dyes such as methylene blue. • This neutral MOF-type adsorbent could be used for the potential separation of dyes bearing opposite charges. [ABSTRACT FROM AUTHOR]

The construction of acid-base resistant materials for elimination of organic contaminations in water under the sunlight conditions is very important for the protection of our living surroundings. Metal-organic frameworks (MOFs) are promising candidates for photocatalytic applications, but many of them suffer from poor framework stability under the acidic or basic conditions. In this study, by using a bifunctional ligand 4-(4-carboxyphenyl)-1,2,4-triazole (HCPT) featuring both carboxylate and azole groups, a new polyoxometalate-based MOF formulated as {[Cu 8 Cl 5 (CPT) 8 (H 2 O) 4 (HSiW 12) (H 2 O) 20 (CH 3 CN) 4 } n (1) has been prepared via a solvothermal approach. Complex 1 shows a 3D 2-fold interpenetrating scu -type network based on the four-connected {Cu 2 (CO 2) 4 } and eight-connected {Cu 4 Cl}7+ clusters, and could be stable in a wide range of pH values f0 to 14). Apart from its excellent framework stability, complex 1 shows a high photocatalytic efficiency for the degradation of rhodamine B (RhB) by visible light irradiation and nearly 97% of the RhB was degraded within 70 ​min. To our knowledge, complex 1 represents the first case of polyoxometalate-based MOFs constructed from the mixed-cluster units. A new polyoxometalate-based MOF has been prepared via using a bifunctional ligand 4-(4-carboxyphenyl)-1,2,4-triazole featuring both carboxylate and azole groups. The as-prepared MOF shows a 3D 2-fold interpenetrating scu -type network based on the four-connected {Cu 2 (CO 2) 4 } and eight-connected {Cu 4 Cl}7+ clusters, and could be stable in a wide range of pH values (0–14). This MOF shows a high photocatalytic efficiency for the degradation of rhodamine B (RhB) by visible light irradiation with nearly 97% of the RhB was degraded within 70 ​min, and it represents the first case of polyoxometalate-based MOFs constructed from the mixed-cluster units. Image 1 [ABSTRACT FROM AUTHOR]