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Two novel cyanostilbene-modified tetraphenylethene derivatives were constructed by Williamson etherification, Suzuki coupling and Knoevenagel condensation reactions. Both compounds exhibited aggregation-induced emission and strong solid-state fluorescence behaviors with extremely high fluorescence quantum yield due to the distorted molecular conformation. Strangely, the compound without additional phenyl spacer did not show mechanochromic behavior, whereas, the compound with an additional phenyl spacer exhibited distinct mechanochromic behavior with the red-shifted emission wavelength from 480 nm to 503 nm upon grinding. The distinct differences in mechanochromic behaviors between the reported compounds could be attributed to that the additional phenyl spacer had benefits for the molecular planarization with external mechanical force. This investigation provided a method to construct mechanochromic material with aggregation-induced emission behavior and high solid-state fluorescence quantum yield and promoted the utilization in rewritable luminescent paper. Two novel AIE-active cyanostilbene-modified tetraphenylethene derivatives were prepared and the additional phenyl spacer induced distinct AIE behaviors, solid-state fluorescence and mechanochromic behaviors. [Display omitted] • Two novel AIE-active cyanostilbene-modified tetraphenylethene derivatives were obtained. • The incorporation of phenyl induced different solid-state fluorescence with high fluorescence quantum yield. • The incorporation of more phenyl induced big difference in mechanochromic behavior. [ABSTRACT FROM AUTHOR]

Eu3+ and Tb3+ as central ions and 1,4-phthalic acid (H 2 BDC) as ligand, a dual lanthanide metal-organic framework, Eu-Tb(BDC), was synthesized by co-precipitation method. The products performed stable crystal structure and adjustable fluorescence color. Eu 0.15 Tb 2.85 (BDC) 3.0 was selected as an optimized probe to detect norfloxacin (NFX) in urine, and the fluorescence color was found to transfer from bright yellow to dark cyan and then to strong green with increasing NFX concentration. Mechanism analysis revealed that NFX with low concentration (10−6-10−3 M) stimulated light competition with BDC ligand due to internal filtration effect (IFE), resulting in the gradual fluorescence shutdown of Eu3+and Tb3+. While further increasing concentration of NFX to 10−3-10−2 M, the antibiotic molecules coordinated with lanthanide ions and transitioned their role from competitor to assistant. Where the energy transfer due to antenna effect overwhelmed IFE, the exciting light energy were retransferred to Eu3+ or Tb3+, and the probe's fluorescence restored. Generally, the Eu-Tb(BDC) probe performed fluorescence turn off-on response to norfloxacin with continuous concentration changing. Additionally, when detecting other fluoroquinolone antibiotics, the fluorescence of Eu 0.15 Tb 2.85 (BDC) 3.0 changed from bright yellow to bright blue and eventually to dark red, which was attributed to the different coordination degrees of various antibiotic molecule with Tb3+ and Eu3+. It can be used to distinguish norfloxacin from other fluoroquinolone antibiotics. Synthesis route of Eu-Tb(BDC) and its fluorescence sensing mechanism and application of test paper visualization. [Display omitted] • Europium-terbium co-doped metal-organic framework was prepared by coprecipitation method and applied to test paper. • Eu-Tb(BDC) can quantitatively sense and distinguish between norfloxacin and other fluoroquinolone antibiotics. • The phenomenon of fluoroquinolone antibiotics turning off to Turn on has been discussed. [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]

Glutamic acid (Glu) is a biomarker of some neuropathological diseases, whose detection is of significance in early medical diagnosis. A 3D terbium metal-organic framework (Tb-ddb) is constructed from 1,3-di(3′,5′-dicarboxylphenyl)benzene (H 4 ddb) with Tb3+, displaying the 5D 4 → 7F j (j = 6-3) transfers of Tb(Ⅲ) at 490, 543, 584, and 621 nm. Tb-ddb has a high stability in water or common organic solvents. The sensitivity test shows a linear fitting equation of I 0 /I = 0.00443·C Glu + 0.93563 with LOD = 1.40 μM at C Glu = 0–500 μM. The detection performance of Tb-ddb is not affected by seven interferents of amino acids. High durability is supported by the stable emission intensities at 543 nm of blank Tb-ddb and Tb-ddb/Glu suspensions in five fluorescence quenching-recovery cycles. The returned C Glu close to the set C Glu and the recoveries around 100% demonstrate Tb-ddb sensing Glu in human urine and serum is reliable. The linear relationship between green value of the Tb-ddb strip and C Glu can realize the on-site Glu detection. Tb-ddb can be regarded as a promising fluorescence turn-off sensor to Glu with high sensitivity, selectivity and durability. A turn-off fluorescence sensor of Tb-ddb exhibits a quantitative fluorescence quenching to glutamic acid in human urine and serum. [Display omitted] • Tb-ddb shows a LOD of 1.40 μM in a linear range of 0–500 μM Glu, better than or compared to most MOF-based Glu sensors. • Tb-ddb shows high accuracy and the recovery around 100% for sensing Glu in human urine and serum. • Paper-based Tb-ddb shows a possbility for the on-site Glu detection with a linear equation of the green values vs C Glu. [ABSTRACT FROM AUTHOR]

MoS 2 and WS 2 are two promising candidates for photocatalytic hydrogen production, and pyrolysis is one of the conventional and useful methods for their preparations. However, systematic investigations about the influences of pyrolysis conditions on their photocatalytic hydrogen production performances are still unreported. Then in this paper, a series of pyrolysis products of ammonium tetrathiomolybdate (ATM) and ammonium tetrathiotungstate (ATT) were prepared by changing the pyrolysis temperature and time. Besides, detailed characterizations were conducted to find out the changes in composition, crystallinity, and morphology. Especially, to get optimal pyrolysis conditions for the preparation of high-performance MoS 2 and WS 2 , their photocatalytic hydrogen production activities were investigated. The results showed that although along with the changes in pyrolysis conditions, the overall changes in composition, crystallinity and morphology are similar for ATM and ATT products, there are significant differences in their performances. For the pyrolysis of ATM, the products obtained under lower temperatures exhibit relatively higher activity than those obtained under higher temperatures. The performance of sample ATM-400-1 (the pyrolysis product obtained under 400 °C 1 h) is the highest and those of two ATM-600 samples (obtained under 600 °C 1 h and 600 °C 2 h) are the lowest. On the contrary, for the pyrolysis of ATT, the higher-temperature products possess much higher performance than the lower-temperature ones. The activity of ATT-400-2 is the highest and those of two ATT-250 samples are the lowest. On the other hand, unconventional crystallized WS 3 was unexpectedly obtained through the pyrolysis of ATT at 300 °C for the first time. This work can offer useful information for the preparation of WS 2 and MoS 2 -based photocatalysts. The optimal conditions for preparation of MoS 2 and WS 2 by pyrolysis of ammonium tetrathiomolybdate (ATM) and ammonium tetrathiotungstate (ATT) were achieved and the reasons for performance difference of different products were elucidated. [Display omitted] • Pyrolysis products of ATM and ATT were systematically characterized. • Hydrogen production performances of pyrolysis products were detailed investigated. • Reasons for performance differences between ATM and ATT products were elucidated. • Crystalline WS 3 was achieved for the first time by the pyrolysis of ATT. [ABSTRACT FROM AUTHOR]

The oxygen evolution reaction is more challenging than the hydrogen evolution reaction in overall water splitting, not only because the four-electron reaction is more complex but also because the oxidizing environment of the anode reaction is more destructive to the electrode material. Generally, such destruction results in the formation of an oxide film that hinders the transition of electrons and subsequently decelerates the succeeding reaction. This paper proposes a transition layer for self-supporting electrodes (NiFe LDH@NiCoP/NF) in which NiCoP grows between the NF and NiFe LDH. The implementation of NiCoP as a transition layer, showcasing excellent antioxidation capability and conductivity, effectively reduced overpotentials and consequently enhanced the catalytic performance. Benefiting from this transition layer, in a 1.0 M KOH, the NiFe LDH@NiCoP/NF catalyst exhibited outstanding OER and HER performance, requiring only 281 and 102 mV, respectively, to achieve 100 and 10 mA cm−2, and also exhibited a cell voltage for overall water splitting of 1.56 V at 10 mA cm−2. The NiFe LDH@NCP/NF composite was successfully synthesized by employing hydrothermal, phosphorization, and electrodeposition techniques to introduce the NCP transition layer between NiFe LDH and the NF substrate. The excellent performance in both OER and HER endows the NiFe LDH@NCP/NF composite with significant potential in the field of overall water splitting. [Display omitted] • NiFe LDH@NCP/NF was obtained by introducing a needle-like NiCoP (NCP) between the amorphous NiFe LDH and the NF substrate. • The NCP, with its excellent antioxidation capability and conductivity, enhances the OER performance of the NiFe LDH@NCP/NF. • By optimizing the electrodeposition time of NiFe LDH, the electrochemical active surface area was maximized. • During the overall water splitting, the NiFe LDH@NCP/NF electrode attains a low voltage of 1.56 V at 10 mA cm−2. [ABSTRACT FROM AUTHOR]

Metal-organic frameworks (MOFs) have been widely used in filed of electrochemistry. Compared with traditional inorganic porous materials, the polyvalent pyridinecarboxylic acid ligands have many advantages which contains more active sites, flexible coordination mode, adjustable structure. Therefore, it becomes good choice for constructing MOFs materials with excellent performance. In this paper, a novel MOF was synthesized by pyridine polycarboxylic acid ligand and CoCl 2 ·6H 2 O using solvothermal method. The physicochemical properties were characterized by FT-IR, powder diffraction and thermogravimetry. Single crystal X-ray diffraction reveal that MOF-1 crystallizes in monoclinic system with P 2 1 / C space group. The central Co2+ ions have a dual core structure with 5 and 6 coordination, respectively. The carboxyl groups show two kinds of coordination modes μ 2 : η1: η1 and μ 2 : η1: η2, and the pyridine N atoms also coordinate to form a three-dimensional network structure. Electrochemical experiments show that MOF-1 has a lower overpotential (339.4 mV) and Tafel slope (65.3 mV·dec−1) with higher ECSA and better OER kinetics. A large number of exposed active sites indicate that the MOF has higher potential as catalyst for oxygen evolution reaction. [Display omitted] • A Co-MOFs based on pyridine polycarboxylic acid ligand were prepared by a simple hydrothermal method. • Electrochemical test show that the MOFs has a lower overpotential and Tafel slope with higher ECSA and better OER kinetics. • MOFs exhibit a porous three-dimensional network structure. [ABSTRACT FROM AUTHOR]

Porous materials with high adsorption capacity can enhance the efficiency of water-based adsorption heat transformation systems. The composites salt in porous matrix (CSPM) are considered to be very promising materials. In this paper, the UIO-66-NH 2 and UIO-66-NO 2 metal-organic framework were used as the porous matrix to synthesize composites with CaCl 2 as the hygroscopic salt. The water adsorption and desorption performance of the composite materials were studied, and the cycle stability was investigated in a continuous adsorption-desorption experiment. As a result, the hydrophilic UIO-66 based composites exhibited higher water adsorption and heat storage capacity. CaCl 2 @UIO-66-NH 2 achieved a water adsorption capacity of 0.84 g/g at 60% relative humidity (RH) and an energy storage density of 1858 J/g. In addition, the hydrophilic UIO-66 based composites exhibited excellent cycle stability, with the quality decreasing by less than 5% after ten adsorption-desorption cycles. By introducing hydrophilic functional groups, the adsorption capacity, adsorption rate, and thermal storage capacity of CSPMs were improved. [Display omitted] • The hydrophilic functionalized UIO-66 based composites exhibit enhanced water absorption properties. • The hydrophilic functionalized samples have higher energy storage densitywith CaCl 2 @UIO-66-NH 2 reaching 1858J/g. • All samples exhibited good cycle stability and the water adsorption quantity decreased by less than 5% after 10 cycles. [ABSTRACT FROM AUTHOR]

The development of highly efficient and low-cost bifunctional electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is the key to the industrialization of large-scale hydrogen production, while the development of non-precious-metal catalysts that can be substituted for precious-metal materials is the current trend of research. In this paper, nickel foam (NF) self-supported CoFe layered bimetallic hydroxide (LDH)-CuCo 2 S 4 electrocatalysts were prepared using a simple hydrothermal and electrodeposition method. The prepared CuCo 2 S 4 @CoFe-LDH/NF catalysts showed good performance in alkaline water oxidation, proton reduction and overall water decomposition with an overpotential of 293 mV for the oxygen evolution reaction (OER) at a current density of 50 mA cm−2 and 63 mV for the hydrogen evolution reaction (HER) at a current density of 10 mA cm−2. When CuCo 2 S 4 @CoFe-LDH/NF was used as a bifunctional electrocatalyst for the decomposition of water, the voltage of the 10 mA cm−2 electrolyzer was only 1.54 V, and the stability of the electrolyzer reached 60 h, which was superior to other bifunctional catalysts. [Display omitted] • CoCu-LDH grows firmly on nickel foam by a hydrothermal method. • Vulcanization at room temperature makes the experimental conditions milder and simpler. • An electrodeposition method was used to grow nanosheets on nanowires. [ABSTRACT FROM AUTHOR]

The luminescent properties of main-group metal-organic frameworks (MOFs) can usually be modulated by organic ligands, and thus realizing temperature sensing over a wide range. Herein, a step-by-step decoration of hydroxyl groups on terephthalic acid (BDC) ligand was involved to regulate the excited-state intramolecular proton transfer (ESIPT) process of the ligands and thus the temperature sensing performance. Accordingly, the OH groups located on these ligands effectively regulate their luminescence sensing property with the absolute temperature sensing sensitivity following the order: DHBDC (0.62% K−1) > OHBDC (0.26% K−1) > BDC (no obvious linear relationship). Luminescent main-group MOFs with these ligands, namely MIL-53-Al-BDC/OHBDC/DHBDC and SNNU-301-Mg-DHBDC, were further selected to explore the temperature sensing performance. Thanks to the unique fluorescence characteristics of the DHBDC ligand, MIL-53-Al-DHBDC and SNNU-301-Mg-DHBDC both demonstrate excellent temperature sensing ability over a wide range (80–480 K) with the absolute temperature sensing sensitivity of 0.32% K−1 and 0.35% K−1, respectively. The compared luminescent spectra show that the stronger electron-donating ability of the substituents on the benzene ring can lead to the higher the electron cloud density in the MOF structure, and thus bring a higher temperature sensing sensitivity. This paper pays a new way for the exploration of practical wide-range MOF thermometers. [Display omitted] • Step-by-step regulation of ESIPT process by hydroxyl groups. • Main-group MOFs with ESIPT ligands. • MOFs with excellent wide-range temperature sensing performance. [ABSTRACT FROM AUTHOR]

Due to high stability, safety and energy density properties, solid-state lithium-ion is expected to be used for the next-generation batteries. Recently, new solid electrolyte materials with high-ion conductivity have been widely explored. In this paper, a novel solid electrolyte LiNaSrP 2 O 7 was successfully prepared by the conventional solid-state method and characterized by X-ray diffraction (XRD) analysis, electron microscopy and optical and impedance spectroscopy. XRD and Rietveld analysis show that the sample crystallizes in the orthorhombic structure with Pnma space group. The UV–Vis measurement, performed from 200 nm to 800 nm, show a direct optical band gap evaluated at 5.26 eV. Both impedance and modulus studies reveal the temperature-dependent non-Debye type relaxation conduction phenomenon. AC conductivity has been studied to understand the conduction mechanism. AC conductivity results show the role of quantum mechanical tunneling of charges in the conduction mechanism. Moreover, the electrical conductivity and modulus analysis findings revealed the activation energy obtained from suggests that the transport takes place through the ion hopping mechanism, dominated by the motion of the mixed Li+/Na+ ions in the structure of the investigated material. [Display omitted] • The compound crystallizes in the orthorhombic structure with Pnma space group. • Optical study proved that the indirect band gap is around 5.26 eV. • The electrical properties suggesting the semiconductor behavior. • The variation of M″ peak showed a thermally activated relaxation process. • The near value of activation energies obtained from the analysis of M″, dc-conductivity and hopping frequencies data confirms that the transport is through ion hopping mechanism, dominated by the motion of the mixed Li+/Na+ ions in the structure of the investigated materials. [ABSTRACT FROM AUTHOR]

In this paper, Short-time X-ray irradiation induced long afterglow and photostimulated luminescence from Sr 2 GeO 4 : Pr3+ has been observed. Under the X-ray irradiation, Sr 2 GeO 4 : Pr3+ can produce long afterglow and photostimulated visible luminescence mainly located at 490, 547 and 629 nm, which are attributed to 3P 0 →3H 4 , 3P 0 →3H 5 and 3P 0 →3H 6 of Pr3+, respectively. More important, even 5 s X-ray irradiation which was less than the X-ray damage from one CT scan, can induce 5400 s afterglow emission. Furthermore, due to its excellent photostimulated luminescence properties, the afterglow emission intensity of Sr 2 GeO 4 : Pr3+can be significantly improved under the radiation of 980 and 808 nm lasers and the emission intensities can still be maintained even after 12 testing cycles. The thermoluminescence results show that Pr3+ doping produces three different traps. Among these, the traps with 0.64 and 0.71 eV trap depth result in excellent X-ray long afterglow luminescence of Sr 2 GeO 4 : Pr3+. While the deep trap of 0.96 eV determines the photostimulated luminescence properties. These results indicate that Sr 2 GeO 4 :Pr3+ possesses excellent long afterglow and photostimulated luminescence under the X-ray irradiation in safety range, which thus can be regarded as in vivo light source to efficiently conduct photodynamic therapy in the future. Sr 2 GeO 4 :Pr3+ long afterglow material has been prepared, which has the characteristics of Short-time irradiation by X-ray induced long afterglow and photostimulated luminescence. The result showed that the afterglow emission peaks are mainly located at 490 nm, 547 nm and 629 nm, corresponding to the 3P 0 →3H j (j = 4, 5, 6) characteristic transitions of Pr3+, respectively. When the doping concentration of Pr3+ is 0.5 %, the sample possesses the best afterglow and the afterglow emission can still be observed after 5400 s. And the X-ray excitation can produce much better afterglow performance than 254 nm excitation. In addition, the sample also showed good afterglow performance under short-time (5 s) X-ray radiation. At the same time, the sample possesses strong PSL characteristics under the excitation of 980 nm and 808 nm lasers and still maintains strong PSL afterglow intensity after 12 cycles of measurements. Furthermore, the trap density under X-ray excitation is much higher than that under UV excitation, which thus produce much longer afterglow emission under the X-ray irradiation. These results indicate that Sr 2 GeO 4 :Pr3+ possesses excellent long afterglow and photostimulated luminescence under the X-ray irradiation in safety range, which thus can be regarded as in vivo light source to efficiently conduct photodynamic therapy in the future. [Display omitted] • X-ray induced long afterglow material Sr 2 GeO 4 :Pr3+ shows excellent photostimulated luminescence properties. • Sr 2 GeO 4 :Pr3+ showed good afterglow performance under short-time (5 s) X-ray radiation. • A model is presented to clarify the afterglow mechanisms of Sr 2 GeO 4 :Pr3+. [ABSTRACT FROM AUTHOR]

As an important next-generation photoelectric material, the controlled synthesis of two-dimensional molybdenum disulfide (2D MoS 2) with high uniformity is imperative. Traditional MoS 2 growth methods in the open space usually require a large amount of raw materials and have poor uniformity of growth results. In this paper, we report a space-confined method for uniformly growing large MoS 2 flakes on the SiO 2 /Si substrate. As the precursor film coated on the bottom substrate is restricted in a small confined space between the top and bottom substrates separated by a small spacer, it is efficiently utilized, achieving large MoS 2 flakes with good uniformity on the top substrate. By further tuning the content of NaCl catalyst in the precursor, single-layer or multi-layer MoS 2 flakes can be obtained in a controlled manner, and well characterized by Raman, XPS, PL and AFM. The uniform distribution of Mo-containing species and its high concentration in the confined space, contributing to the efficient growth of uniform large MoS 2 flakes. This research will provide guidance for rational synthesis of 2D MoS 2 flakes on dielectric substrates. A space-confined method is proposed to grow large MoS 2 flakes uniformly and efficiently on the SiO 2 /Si substrate. [Display omitted] • A space-confined method for growing large MoS 2 flakes uniformly and efficiently on the SiO 2 /Si substrate is proposed. • This method is featured with ultralow precursor consumption and high growth uniformity of MoS 2 flakes. • Monolayer or multilayer MoS 2 flakes can be obtained in a controlled manner by adjusting the content of NaCl catalyst. [ABSTRACT FROM AUTHOR]

Replacement of the Harber-Bosch process for urea production by electrochemical reduction is an attractive alternative that reduces chemical energy consumption, reduces environmental pollution and improves efficiency. Among them, the method of electrochemical coupling of N 2 and CO 2 to produce urea has been widely used, but the inertness of nitrogen and nitrogen bond and high dissociation energy make it difficult to activate N 2. Meanwhile, the method of synthesis of urea by NO 3 RR came into being. Nitrate in sewage is more abundant and convenient than nitrogen raw material, and more importantly, the dissociation energy of N O bond is much lower than that of N N. In this study, the transition metal embedded lithium COF catalyst was taken as an example, and the optimal electrocatalyst was selected through screening and synthesis energy barrier comparison to study the mechanism of urea synthesis. We studied the NRR and NO 3 RR paths, respectively, and found that the NRR synthesis of urea was optimal on the LiTaS-Pc VPPs catalyst, with a limiting potential value of −0.57V, and the NO 3 RR synthesis of urea was optimal on the LiVS-Pc VPPs catalyst, with a limiting potential value of −0.39V. It is found that NO 3 RR on the lithium catalyst is relatively better, and the required limit potential value is lower. In addition, the advantage of choosing lithium metal doping as catalyst in our study is that HER can be well inhibited, and the desorption of urea is easier than that of transition metal doping (taking molybdenum as an example). This study points out the direction for the electrocatalytic synthesis mechanism of urea, and provides a new idea for the selection of catalysts, paving the way for the future production of urea. This paper investigated the mechanism of urea synthesis using NRR and NO 3 RR on lithium-based COF series catalysts (LiTMS-Pc VPPs), respectively. Among them, the adsorption of reactive nitrogen, C–N coupling, and urea synthesis are mainly carried out on LiTMS-Pc. The process of generating CO via CO 2 RR on VPPs overflows onto the phthalocyanine structure and undergoes C–N coupling with nitrogen-containing intermediates to synthesize urea. Comparing and organizing the two methods of urea synthesis, NO 3 RR is relatively superior. In addition, a comparison was made between the synthesis of lithium-based catalysts and transition metal molybdenum catalysts, and it was found that the lithium-based catalyst improved urea removal. [Display omitted] • The synthesis of urea on a two-dimensional carbon-rich catalytic structure is studied using the cascade catalytic approach. • The main group metal lithium is embedded in the catalyst, and the synthesis of urea under the action of lithium-based and molybdenum-based catalysts is studied and compared. • Compare excellent urea synthesis using N 2 and NO 3 as different nitrogen sources. [ABSTRACT FROM AUTHOR]

Hydrogen energy is considered as powerful alternative to fossil energy owing to its virtues of high energy density, eco-friendliness and low cost. Metal-organic frameworks (MOFs) can be used as ideal precursors through carbonization used as electrocatalysts in energy storage and coversion fields, which will inherit the merits of ordered structures and large surface area. In this paper, Co-G@C centering on Cobalt as hydrogen evolution electrocatalyst synthesized by carbonizing CUST-515 decorated with glucose as carbon source. Co-G@C possess the overpotentials of 162 and 193 mV at the current density of 10 mA cm−2 in alkaline and acid solutions with long as 24 h stability. This good effect is attributed to the coupled effect of Co and carbon layers as well as the large and ordered pore structures induced by glucose and CUST-515 carbonization, which can accelerate the charge transfer. This work can come up with a reference for the synthesis of non-expensive metal electrocatalysts for water splitting applications. the electrocatalyst Co-G@C was synthesized by one-step high-temperature calcination by mixing glucose with A new MOF (CUST-515). Co-G@C exhibits excellent HER properties in alkaline and acidic solutions. [Display omitted] • A new MOF (CUST-515) was prepared by solvothermal method. • The electrocatalyst Co-G@C was synthesized by one-step high-temperature calcination. • Co-G@C exhibits satisfactory hydrogen production performance. • This research provides a reference to synthesize non-noble metal electrocatalysts. [ABSTRACT FROM AUTHOR]

Urease may rapidly hydrolyze urea, causing a significant amount of ammonia to be released and decreasing the efficacy of urea fertilizers. However, urease inhibitors (UIs) can inhibit the interaction between urease and urea so that ammonium nitrogen can be absorbed by crops for a long time. In this paper, we developed and fabricated two Cu-based coordination polymers (Cu-CPs) to function as UIs by combining two aromatic carboxylic acids and a bis-pyridine-bis-amide ligand, which demonstrate outstanding urease inhibitory efficacy. Cu-CP-1 exhibits a pronounced inhibitory effect on the inhibitory activity of jack bean urease while the semi-inhibitory concentration (IC 50) value was 0.74 ± 0.01 μM, whereas the IC 50 value of Cu-CP-2 was 4.77 ± 0.51 μM. Furthermore, inhibitory activity against urease, kinetic, molecular docking, and comparisons of the title Cu-CPs and other complex-based materials have been comprehensively investigated. More importantly, the oxygen atoms of μ 2 -OH and –COO play important roles in urease inhibition activity. The structure–function relationship were further discussed which indicates that Cu-CPs can be used as a kind of UIs. By using different O-donor second auxiliary ligands, we have designed and synthesized two Cu-based CPs to operate as urease inhibitors which show excellent urease inhibitory activity. [Display omitted] • The development of UIs has been a matter of great concern to researchers. • Two Cu-CPs have been synthesized by using diverse O-donor ligands. • The Cu-CPs are served as UIs and show excellent urease inhibitory activity. • Inhibitory activity, kinetic, molecular docking of the Cu-CPs have been studied. [ABSTRACT FROM AUTHOR]

In this paper, first-principle calculations based on density-functional theory (DFT) and plane-wave pseudopotential basis for g-C 3 N 4 /ZnO composites were carried out using Quantum Espresso (QE) code. The g-C 3 N 4 /ZnO composite photocatalytic materials were prepared by solid-phase calcination and characterized by XRD, SEM, and FT-IR. Photocatalytic degradation experiments were carried out under LED light irradiation, using the dye rhodamine B (RhB) and the antibiotic tetracycline hydrochloride (TC) as simulated degradation targets. The degradation performance of the composites was tested using the commercially available pesticide glyphosate. The removal of total nitrogen (TN), total phosphorus (TP), and chemical oxygen demand (COD) from water samples was tested using real sewage livestock wastewater. The photocatalytic degradation mechanism of the composites was explored by free radical trapping experiments. Finally, the MTT cytotoxicity test demonstrated that the g-C 3 N 4 /ZnO composite photocatalytic materials are non-cytotoxic and are expected to be used in wastewater treatment. Photocatalytic degradation diagram. [Display omitted] • In this study, a combination of theoretical calculations and experiments was used to investigate the g-C 3 N 4 /ZnO composite photocatalytic materials. • RhB and TC were taken as simulated degradation targets to test the degradation performance of g-C 3 N 4 /ZnO composite photocatalytic materials, and then the photocatalytic degradation of the composites for real pesticides was tested using the pesticide glyphosate. • Real sewage livestock wastewater was used to test the removal of total nitrogen (TN), total phosphorus (TP), and chemical oxygen demand (COD) from water samples by the composites. • The material successfully passed the MTT cytotoxicity test, and it can be concluded from the above experiments that the material is expected to be put into the treatment of real sewage. [ABSTRACT FROM AUTHOR]

The irreplaceable silicone materials among the high-tech industry is dimethyldichlorosilane, a monomer whose by-products generated in the synthesis step can be recycled through disproportionation reactions. In this paper, the catalytic activities of NH 2 -MIL-53(Al)@γ-Al 2 O 3 with Brønsted acid active sites and AlCl 3 /NH 2 -MIL-53(Al)@γ-Al 2 O 3 core-shell catalysts with Lewis acid active sites were investigated and compared for the disproportionation to prepare dimethyldichlorosilane by means of the M06-2X/Def2-TZVP hybrid functional method. The results given for structure, energy, vibrational frequency, IRC values, bond order, ELF and LOL analysis were matched. The results showed that AlCl 3 /NH 2 -MIL-53(Al)@γ-Al 2 O 3 core-shell catalyst with Lewis acid was more active. Simulated synthesis and interatomic correlation parameters (bond length/nm and bong angle/o) of NH 2 -MIL-53(Al)@γ-Al 2 O 3 (Cat. ,active site No.1-3) and AlCl 3 /NH 2 -MIL-53(Al)@γ-Al 2 O 3 (Cat.&, Configuration a-d). [Display omitted] • Proposed four- and six-step disproportionation allows recycling of (CH 3) 3 SiCl and CH 3 SiCl 3. • Loading of AlCl 3 presents Lewis catalytic centers, which possess enhanced catalytic activity compared to Brønsted acid. • Optimization of MOFs-based catalysts with core-shell structure, NH 2 -MIL-53(Al)@γ-Al 2 O 3 and AlCl 3 /NH 2 -MIL-53(Al)@γ-Al 2 O 3. [ABSTRACT FROM AUTHOR]

BiFeO 3 has excellent potential as a narrow band gap semiconductor and piezoelectric material for photoelectrochemical decomposition of water (PEC) applications. However, because of its susceptibility to impurities and oxygen vacancy defects during preparation and its high complexation rate of photogenerated carriers, relevant applications are greatly limited. In this paper, BiFeO 3 /CdS heterojunction films were prepared on FTO conductive glass by a very simple and feasible sol-gel and chemical bath method to improve the efficiency of the photoelectrochemical decomposition of water. It was shown based on a series of PEC tests. The photocurrent density of the pure BiFeO 3 thin film photocathode reached −85 μA/cm2 after giving ultrasonic stress conditions. Furthermore, the BiFeO 3 /CdS heterojunction photocathode achieved a photocurrent density of about −230 μA/cm2 at 0 V vs. RHE under the synergistic effect of piezoelectric polarization and the built-in electric field built in the heterostructure. In summary, semiconductor modification approaches using the construction of suitable heterojunction structures can effectively promote the separation and transfer of carriers between interfaces. The use of piezoelectric polarization and the search for appropriate energy level-matched semiconductors to construct heterojunctions can synergistically improve the efficiency of piezoelectric photocatalysis. The composite of BiFeO 3 and CdS to form type II heterojunction effectively improves the photoelectrocatalytic performance of BiFeO 3 under piezoelectric effect. [Display omitted] • Both BiFeO 3 and CdS films are in the form of nanosheets and the fabrication process is simple and can be done in the laboratory. • Compared with the enhancement of piezoelectric effect under ultrasonic condition, the internal electric field formed by heterojunction can further increase the concentration of photogenerated carrier, thus improving its separation efficiency. [ABSTRACT FROM AUTHOR]

It's still a challenge to design reasonably efficient catalyst using non-noble metal for the oxygen evolution reaction (OER). In this paper, we use a simple one-step electrodeposition method to load Ce and S co-doped NiFe amorphous alloys onto Cu(OH) 2 nanorod arrays. The excellent oxygen electrocatalytic performance of the catalyst NiFeCeS/Cu(OH) 2 /CuF is attributed to the electronic environments of the active sites of Ni and Fe regulated by heteroatomic sulfur and cerium, which promote the transfer of the oxygen precipitation intermediates to the higher valence states. Meanwhile, the highly conductive substrate accelerates the electron transfer efficiency of the catalyst material, and the loose nanostructure increases the specific surface area, exposing more active sites. NiFeCeS/Cu(OH) 2 /CuF shows outsanding electrocatalytic activity for oxygen evolution with a low overpotential of 227 mV at a current density of 10 mA cm−2 in alkaline medium. Moreover, the nanocomposite catalyst also exhibits rapid reaction kinetics and long-term stability and durability. In this work, an efficient oxygen precipitation catalyst is reported, which indicates that non-precious metal-based electrocatalysts have great potential for application in water electrolysis and provides a basis for the rational design and synthesis of nanorod array catalysts with unique structures. Using a simple one-step electrodeposition method to load Ce and S co-doped NiFe amorphous alloys onto Cu(OH) 2 nanorod arrays. NiFeCeS/Cu(OH) 2 /CuF shows outsanding electrocatalytic activity for oxygen evolution with a low overpotential of 227 mV at a current density of 10 mA cm−2 in alkaline medium. [Display omitted] • Co-doping of Ce and S improved the intrinsic activity of NiFe catalysts. • Cu(OH) 2 nanorods increase the number of active sites in catalysts. • The one-step co-deposition technique is simple, efficient and repeatable. [ABSTRACT FROM AUTHOR]

To search for more high-performance crystalline proton conducting materials and to accelerate the related research progress, in this paper, a one-dimensional coordination polymer (CP), [Co(BBOT) 2 (H 2 O) 3 ·2H 2 O] n (1) (H 2 BBOT = N-benzoyl-N′-(4-benzoxy)thiourea) was firstly prepared by solvent volatilization approach. Subsequently, the thermal, H 2 O and chemical stabilities of the CP were tested and its high structural stability was confirmed. Furthermore, in 1 , a stable solid three-dimensional framework can be constructed by intermolecular H-bonds and stacking interactions between phenyl units. Then, utilizing the AC impedance determination, the dependence of the proton conductivity of this CP on temperature and humidity in the water vapor environment was explored and the positive correlation was verified. Excitingly, the optimized proton conductivity of this compound under specific test conditions (100 °C/98 % relative humidity) can be as high as 10−4 S/cm, being in the forefront of similar crystalline solid materials. Finally, according to the value of activation energy and the characteristics of crystal structure, we speculate on the proton conduction mechanism. Proton conductivity of a CP under variable humidity and temperatures was explored. Its highest proton conductivity can attain up to 10−4 S/cm, and its proton-conduction mechanism was speculated. [Display omitted] • One carboxylate-based Co(II) coordination polymer was prepared. • Its structure was characterized by single-crystal X-ray diffraction. • Its water-assisted proton conduction was explored. • The proton-conducting mechanism was speculated. [ABSTRACT FROM AUTHOR]

By introducing functional groups into the isophthalate ligand to decorate the pore of the MOFs, gas adsorption and separation performance can be tunable. In this paper, two isostructural 2D Co-MOFs, [Co(5-MIA)(bpy)]·H 2 O (1) and [Co(5-EIA)(bpy)]·H 2 O (2) (5-H 2 MIA = 5-methoxyl-isophthalic acid; 5-H 2 EIA = 5-ethyoxyl-isophthalic acid; bpy = 4,4′-bipyridine), with different functionalized pore surfaces and channel sizes were designed and constructed. The structures and performance of the two Co-MOFs were analyzed by SCXRD, PXRD, IR, TGA, and gas sorption (CO 2 , C 2 H 2 , CH 4 , CO, and N 2). Attributed to the methoxyl of isophthalate skeleton, 1a (activated 1) shows enhanced CO 2 uptake over other gases. In spite of decreased pore sizes (3.49 Å) compared with 2a (4.38 Å), the CO 2 uptake of 1a (43.41 cm3 g−1) is larger than that of 2a (22.39 cm3 g−1) at 298 K and 100 kPa. Compound 1 incorporates methoxyl groups into the narrow channel, and exhibits the cooperative effect of CO 2 -preferential due to adsorbent-adsorbate coactions and size sieving. GCMC simulation has been used to explore the adsorption coactions of CO 2 and 1 , and the results confirmed that the methoxyl groups in the channel are the main binding sites of CO 2. At ambient temperature and 100 kPa, the IAST selectivities of CO 2 /C 2 H 2 (1:1), CO 2 /CH 4 (1:1), C 2 H 2 /CH 4 (1:1), CO 2 /CO (1:2) and CO 2 /N 2 (15:85) on 1a were 2.6, 39.3, 13.3, 282 and 1433, respectively. The easy activation and regeneration, excellent thermal and humidity stability, and good reusability, make 1 a hopeful adsorbent for adsorption and separation of CO 2. By introducing functional groups into the isophthalate ligand to decorate the pore of the MOFs, gas adsorption and separation performance can be tunable. Two isostructural 2D Co-MOFs with different functionalized pore surfaces and channel sizes were constructed and show different C 2 H 2 /CH 4 and C 2 H 2 /CO 2 gas separation properties. [Display omitted] • Title compound represent the first example of 3D MOF based on 5-H 2 MIA and bpy. • 1a (activated 1) shows enhanced CO 2 uptake over C 2 H 2 , CH 4 , CO and N 2. • 1a shows an excellent reuse performance. [ABSTRACT FROM AUTHOR]

In this paper, Ce–Ho–Tb co–doped Bi 2 O 3 compositions were developed using the solid–state reaction method under atmospheric conditions. The XRD patterns confirm the stability of the cubic δ–phase in Ho and Tb–rich compositions but not in the Ce–rich ones, which consist of mixed phases, such as α and β. Peak shifting is additionally apparent in the magnified XRD diagram of primary peaks regarding the (111) diffraction plane, suggesting that the structural features change with doping. At 700 °C, the highest conductivity is found to be 0.30 S/cm for the composition 8Ce4Ho4Tb, and it is comparable to the single–doped (Bi 2 O 3) 0.80 (Er 2 O 3) 0.20 system at the same temperature. The FE–SEM images show the aggregation, particularly in images of Ce–rich compositions, implying that large cations have difficulty penetrating the lattice. The porosity over the surface is dense, particularly for Tb–rich compositions, indicating a decline in conductivity with doping. The cubic δ–phase of Bi 2 O 3 crystal, an excellent ion conductor, is capable of being stabilized at room temperature in Ho-rich compositions. Arrhenius plots of conductivity clearly show that the content ratios of 1:2:1, which is a specific ratio, play a key role in achieving the highest conductivity stable Bi 2 O 3 electrolytes. [Display omitted] • A high ion conductor, δ-Bi 2 O 3 phase was effectively stabilized in Ho and Tb-rich compositions. • The highest conductivity was determined to be 0.30 S/cm, which is greater than 20ESB electrolyte. • In several compositions, the order-disorder transition on the Arrhenius plots is noticeable. • The FE-SEM pictures revealed a local aggregation on the surface, particularly in the Ce-rich specimens. [ABSTRACT FROM AUTHOR]

To study hydrogen diffusion properties is of importance in design of new proton conductors. In the past, the chemical diffusion coefficient of hydrogen in proton conductor was usually obtained by the manual calculation method that largely depends on judgment ability of researchers, so calculation accuracy is difficult to control. To solve this problem, a mathematical algorithm and C language computer program were designed to calculate the chemical diffusion coefficient based on Fick's second law and Romberg numerical integral, in which the chemical diffusion coefficient is obtained by fitting measured electrical resistance relaxation curve based on. In addition, the algorithm can be extended to calculate the chemical diffusion coefficient in some special cases with incomplete measured electrical resistance relaxation curve or inaccurate measured values of R 0 and R ∞ based on modified algorithm of R 0 and R ∞ , what cannot be handled by the manual calculation method. The chemical diffusion coefficient of self-synthesized Yb doped CaZrO 3 proton conductor were calculated by using the algorithm and compared with the manual calculation method. The results show that the algorithm has the advantages of high precision and powerful computing function. The new algorithm is potential to be widely applied to the calculation of the chemical diffusion coefficient for hydrogen in proton conductors to replace the manual calculation method. In this paper, a mathematical algorithm and computer program were designed to calculate the diffusion coefficient of hydrogen in proton conductor based on analysis of the relaxation curve of electrical resistance upon substitution of the protons by deuterons. The algorithm has the advantages of high precision and powerful computing function, so it is expected to replace the manual calculation method we used in the past and be widely applied to the calculation of hydrogen diffusion coefficient in proton conductors. [Display omitted] • Yb doped CaZrO 3 proton-conducting solid electrolyte was prepared. • The electrical properties of Yb doped CaZrO 3 were studied. • Based on Fick's second law and Romberg numerical integral, a mathematical algorithm and C language computer program were designed to calculate the chemical diffusion coefficient. • The algorithm is expected to replace the manual calculation method and be widely applied to calculation of hydrogen the chemical diffusion coefficient in proton conductors. [ABSTRACT FROM AUTHOR]

This paper reports the synthesis, structure, BFDH crystal morphology, Raman and Infrared spectroscopic studies of three novel metal orthophosphate salts MII(Ga 0.5 Sb 0.5)(PO 4) 2 (MII= Sr, Pb, Ba), abbreviated [Sr], [Pb], [Ba]. The structures of these phases are refined from X-ray powder diffraction data by the Rietveld method. The yavapaiite [Ba] phase is monoclinic of C2/m space group [Z=2; a= 8.106(4) Å; b= 5.178(3) Å c= 7.806(1) Å, β=94.79(4)°, V= 327(1) Å3]. Its structure consists of layers, running along the (a, b) plane, and built up of corner-connected Ga(Sb)O 6 octahedra and PO 4 3− tetrahedra. The two isotypic phases [Sr]/[Pb] of distorted yavapaiite structure crystallize in the monoclinic C2/c space group (Z=4) with parameters: a=16.455(4)/16.622(7) Å; b=5.158(1)/5.163(2) Å c= 8.005(1)/8.067(3) Å; β=115.49(1)/114.85(2)°, V= 613(1)/628(5) Å3. Their structures consist of MO 10 (M= Sr, Pb), PO 4 3− tetrahedra and Sb(Ga)O 6 octahedra. In [Pb] phase, the Pb is surrounded by eight oxygen atoms (Pb-O: 2.65-2.77 Å) and two oxygen atoms forming abnormal bond distances Pb-O(4) [3.447(3)Å]. The BFDH crystal morphology predicts hight (h k l) facets for each compound, the center-to-plane distances d hkl are slightly strong in the distorted Yavapaiite [Pb/Sr] rather than in [Ba]. The IR and Raman study is performed based on theoretical group analysis considering C s site symmetry of PO 4 3− groups in [Ba], and C i symmetry in [Pb]/[Sr] phases. The assignment and discussion of the observed bands were done by comparison with other yavapaiite materials. The UV–visible investigation reveals direct optical gap energies of values 4.16 eV for [Ba] and 4.24 eV for [Sr], indicating a semi-conducting nature of the prepared materials. Crystal structures, UV absorbance, and and Tauc Plots (F(R)hν)1/2 of versus hν of AII(Sb 0.5 Fe 0.5)(PO 4) 2 (AII = Ba, Pb, Sr) compounds. [Display omitted] • Novel A(Sb 0.5 Ga 0.5)(PO 4) 2 (A= Ba, Pb, Sr) crystal structures are determined and discussed. • The BFDH morphology of [Ba] and [Sr] are simulated from parametres and Laue symmetry of these crystals. • Theoretical analyses are made in assignment of IR and Raman bands for the three phases. • UV–visible absorptions indicate a semi-conducting nature of the synthetised materials. [ABSTRACT FROM AUTHOR]

High-efficiency phosphor with excellent luminescence properties and thermal stabilities is essential for phosphor-converted white light-emitting diodes (w-LEDs). Compared with red and green phosphors, near-ultraviolet excited blue phosphors with high efficiency and excellent thermal stability are still scarce, and the development of efficient blue phosphors remains challenging. NaLi 3 SiO 4 : Eu2+ (NLSO: Eu2+) is a promising narrow-band blue phosphor. In this paper, a series of Na 1-y K y Li 3 SiO 4 : 5%Eu2+ (0.05 ≤ y ≤ 0.2) phosphors were successfully synthesized by high-temperature solid-state reaction through co-doping a small amount of K+ ions in the matrix, significantly improving their luminescence property and thermal stability. Because of the weaker electronegativity of K+ ions, the emission peaks of Na 1-y K y Li 3 SiO 4 : 5%Eu2+ were slightly blue-shifted from 467 to 463 nm compared with those of NLSO: Eu2+. With an increase in the number of K+ ions, the luminescence intensity of the phosphors increased. When the content of the K+ ion reached 0.2, the luminescence intensity of the Na 0.8 K 0.2 Li 3 SiO 4 : 5%Eu2+ (NKLSO: 5%Eu2+) phosphor reached its maximum. Compared to the NLSO: 5%Eu2+ phosphor, the luminescence intensity increased by approximately 300 %. At 150 °C, the luminescence intensity of NLSO: 5%Eu2+ phosphor was retained at 75.98 % compared with room temperature, while the NKLSO: 5%Eu2+ phosphor maintained a luminescence intensity of 84.36 % relative to room temperature, demonstrating excellent thermal stability. The enhanced luminescence performance of the NKLSO: Eu2+ phosphor makes it a promising high-efficiency blue phosphor for phosphor-converted w-LEDs. Through co-doping a small amount of K+ ions into the NaLi 3 SiO 4 : Eu2+, significantly improving the luminescence property and thermal stability. [Display omitted] • A series of Na 1-y K y Li 3 SiO 4 : 5%Eu2+ (0.05 ≤ y ≤ 0.2) phosphors were successfully synthesized through co-doping K+ ions in the matrix. The weaker electronegativity of K+ ions makes it easier for Eu3+ to be reduced to Eu2+. • In luminescence properties, when the content of the K+ ion reached 0.2, the luminescence intensity of the Na 0.8 K 0.2 Li 3 SiO 4 : 5%Eu2+ phosphor reached its maximum. Compared to the NaLi 3 SiO 4 : 5%Eu2+ phosphor, the luminescence intensity increased by approximately 300 %. • The Na 0.8 K 0.2 Li 3 SiO 4 : 5%Eu2+ exhibited superior thermal stability compared to NaLi 3 SiO 4 : 5%Eu2+. The luminescent intensity of NaLi 3 SiO 4 : 5%Eu2+ at 150 °C remains 75.98 % of the room temperature intensity, while the luminescent intensity of Na 0.8 K 0.2 Li 3 SiO 4 : 5%Eu2+ is significantly increased to 84.36 %. • The narrowband blue phosphor Na 0.8 K 0.2 Li 3 SiO 4 : 5%Eu2+ is a potential candidate for n-UV excited w-LEDs applications because of its excellent luminescence properties. [ABSTRACT FROM AUTHOR]

Oxygen vacancy is an inherent defect of aquamarine crystals. The concentration and properties of this defect have an essential influence on aquamarine crystals and optical properties. This paper reports that blue in aquamarine crystals is due to the interaction between Fe2+ and oxygen vacancy. Infrared and Raman spectra showed that more Fe2+ replaced Al3+ in dark sample A than in light sample B. Oxygen vacancies were found in all samples. Dark sample A strongly absorbed the 830 nm band associated with Fe2+ in the UV–Vis–NIR absorption spectrum. The band gap of dark sample A was smaller than that of light sample B, and the difference in band gap was related to the concentration of oxygen vacancies. X-ray Photoelectron Spectroscopy showed that the oxygen vacancy concentration in sample A was higher than that in sample B, which showed that the oxygen vacancy concentration affected the color depth of aquamarines. [Display omitted] • Experimental tests address oxygen vacancies affect the color depth of aquamarine crystals. • More Fe2+ are found in dark sample to replace Al3+, resulting in more oxygen vacancies. • Oxygen vacancies have two functions: balancing electricity prices and introducing defect energy levels into the band gap, reducing bandwidth and improving light absorption performance. • The experimental results show more oxygen vacancies in darker aquamarine crystals. [ABSTRACT FROM AUTHOR]

Developing highly efficient phosphors-converted white LEDs with excellent emissions characteristics in the blue and deep-red spectral regions, is essential for improving artificial white light for plant growth. Due to the characteristic 3P n −1S 0 transitions (n = 0, 1, 2), Sb3+ is considering as an efficient activator emitting light in the desired deep red and far-red spectral regions. In this paper, we successfully developed Sb3+-doped Ca 2 YTaO 6 double perovskite phosphors, showing broadband doublet emission peaks, in the visible spectral ranges. Computational and experimental investigations were used to confirm the phase purity and structural analysis. The photoluminescence excitation and emission spectra, fluorescence decay curves, thermal stability and CIE chromaticity coordinates have been measured and determined to demonstrate the application potential of the Ca 2 YTaO 6 :Sb3+ double perovskites, as suitable phosphors for plant growth acceleration. The blue (420 nm) and deep red (683 nm) emission peaks were observed under 313 nm UV excitation. Efficient energy transfer was observed from the blue emission of the host phosphor to the doped Sb3+ ions, which resulted in an enhancement of the deep-red emission. The appeared dual color emission makes this phosphor a potential candidate for the generation of artificial white light for plant growth. [Display omitted] • Materials having dual emissions in the blue and deep-red spectral regions are promising for plant growth. • Due to the characteristic 3P n −1S 0 transitions (n = 0, 1, 2), Sb3+ is considering as an efficient activator. • We successfully developed Sb3+-doped Ca 2 YTaO 6 double perovskite phosphors. • Doublet emission peaks, in the visible and deep-red spectral ranges. • Ca 2 YTaO 6 :Sb3+ double perovskites, as suitable phosphors for plant growth acceleration. [ABSTRACT FROM AUTHOR]

Manganese oxides represent an environmentally friendly and industrially scalable class of materials exhibiting sorption properties for Sr2+. However, there is a critical challenge of the drop in the exchange capacity in the processes of sorption and desorption. In the paper, there are proposed and have experimentally been tested the routes for enhancing stability of manganese oxides in the cycled ion exchange processes. There were analyzed the properties of the doped and "pure" birnessite in Sr-form and H-form. The strontium exchange capacity of doped Fe, Co, Ni samples increases with increasing cycling, whereas that of an undoped sample decreases. The samples doped with Fe and Co at 150°С proved to be most stable during cycling, with those doped with Ni and Co being such at modification temperature 360°С. Introduction of Ni and Co was evinced to favor preserving both the strontium exchange capacity and selectivity. • Doping birnessite as a method for the synthesis the selective ion exchanger to strontium. • Birnessite repeatedly working in sorption-desorption cycles. • Physical and chemical principles of the regarding birnessite stability. • Principles for choosing dopant ions as applied to ion exchangers. [ABSTRACT FROM AUTHOR]

In this paper, the metal-organic framework material MIL-100(Fe) was synthesized by hydrothermal method, and then combined with LiCl, CaCl 2, and MgCl 2 by the impregnation method, and the resulting composite materials were named M/LiCl, M/CaCl 2 , and M/MgCl 2. MIL-100(Fe) and its composites were characterized by SEM, BET, XRD, and TGA, and the open adsorption properties at different temperatures and RH were explored, and the desorption properties and cycle stability of the materials were explored. Experiments show that the equilibrium adsorption capacity of MIL-100(Fe) is greatly enhanced by the combination with hygroscopic salt, and the equilibrium adsorption capacity of M/LiCl, M/CaCl 2, and M/MgCl 2 is 1.77, 1.03 and 0.58 g/g, respectively, which is 4.4, 2.6 and 1.5 times that of MIL-100(Fe) under the condition of 25 °C and 65% RH. When the ambient RH increases from 35% to 65% at 25 °C, the equilibrium adsorption capacity of MIL-100(Fe) increases from 0.35 g/g to 0.40 g/g, and the equilibrium adsorption capacity of M/LiCl increases from 0.97 g/g to 1.77 g/g. The influence of temperature on the equilibrium adsorption capacity of the adsorbent is negligible, but the increase in temperature will greatly increase the initial adsorption rate of the adsorbent. When RH is 50%, the equilibrium adsorption capacity of M/MgCl 2 at 15–35 °C is 0.51∼0.54 g/g, and the maximum adsorption rate is 2.52∼5.18 g/(g·100 min). MIL-100(Fe) and its composites can be completely desorbed after desorption at 130 °C for 70 min, the desorption rate is ≥98%, and the water vapor residue is ≤0.02 g/g. M/CaCl 2 showed good cycling stability, and the adsorption capacity after 11 cycles was 94% of the first. [Display omitted] • Composites collapse at higher temperatures compared with MIL-100(Fe). • Compared with M/LiCl and M/CaCl 2 , M/LiCl has best equilibrium adsorption capacity. • Under 25 °C and 65% RH, the adsorption capacities of M/LiCl, M/CaCl 2, and M/MgCl 2 were 1.77, 1.03, and 0.58 g/g. • The composite M/CaCl 2 showed good cycling stability. [ABSTRACT FROM AUTHOR]