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The release of industrial effluents into fresh water is a major contributor of water contamination. Therefore, it is highly desirable to develop a viable solution to this alarming issue to improve the quality of clean water. To enhance the photocatalytic efficiency and hence utilization ratio of CuO, a series of CuO–FeSe2 composites with different varying contents of FeSe2 were prepared through facile synthetic methods. X-ray diffraction (XRD) and energy-dispersive X-rays (EDX) analysis verified that the samples were successfully prepared without any contaminating phases. The average crystallite sizes of CuO and FeSe2 were computed to be 29 and 21 nm respectively. For the CuO–FeSe2 composites, the crystallite sizes varied between 25 and 27 nm. The morphology of CuO was comprised of needle-shaped structures, whereas that of FeSe2 was observed to be flower-shaped structures comprising of irregular crystals. A red shift in the bandgap of CuO–FeSe2 composites was observed with the increase in FeSe2 concentration. The prepared photocatalysts were utilized to evaluate their efficiency under visible light against Rhodamine B (RhB). Among all the prepared composites, CuO–75% FeSe2 revealed a remarkable performance and degraded 96% RhB in 180 min. Rate constants for the degradation of the dye were determined by applying the Langmuir–Hinshelwood model. [ABSTRACT FROM AUTHOR]

In this paper, three-dimensional TiO2 nanoflowers (NFs) were prepared by a facile hydrothermal method, and Ag3PO4 was grown in situ following alkali treatment to design and synthesize a Ag3PO4/OH/TiO2 catalyst with excellent photocatalytic activity under visible light. The test results show that the photocatalytic degradation performance of TiO2 NFs after alkali treatment and Ag3PO4 loading is significantly improved. This is because the alkali treatment and the introduction of Ag3PO4 can provide a large amount of –OH, which can be converted to ˙OH under UV irradiation, followed by an increase in the number of active radicals to enhance the photocatalytic degradation performance. Meanwhile, the introduction of Ag3PO4 can effectively improve the light absorption ability of the photocatalyst. Moreover, the in situ growth of Ag3PO4 on TiO2 NFs can construct a high-quality Ag3PO4/TiO2 heterojunction to promote the charge separation and transport. Therefore, the degradation rate of Ag3PO4/OH/TiO2 can reach 90% after 30 min for degrading 3 mg L−1 RhB under visible light. The Ag3PO4/OH/TiO2 photocatalyst designed in the present work provides a new tool for the degradation of organic dyes. [ABSTRACT FROM AUTHOR]

Bismuth oxybromide (BiOBr) nanoflowers were anchored onto kaolinite nanosheets via a calcination method. Assisted by characterization methods including XRD, SEM, and XPS, the microstructures of photocatalysts were comparatively investigated. The findings revealed a close integration of BiOBr nanoflowers with kaolinite, resulting in a gradual phase transition and augmented surface oxygen. Furthermore, the photocatalytic performance was assessed by investigating the degradation of organic dyes under visible light irradiation. Notably, the experimental results demonstrated that the degradation efficiencies of BiOBr/kaolinite composites were higher than that of pure BiOBr. The ⋅O2− was proven to be the major active radical in the photocatalytic process. This study presents a straightforward approach for fabricating BiOBr‐based photocatalysts, showcasing their enhanced performance in organic dye degradation under visible light. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: A photocatalytic [3+2] annulation of alkenes with vinyl azides was developed under irradiation by visible light in the presence of organic dye photocatalysts. Broad substrate scope and high functional group tolerance were demonstrated by more than 50 examples. The reaction provides a novel and efficient method for the synthesis of polyfunctionalized pyrroles under very mild metal‐free conditions without other additives. [ABSTRACT FROM AUTHOR]

This study reports magnetic graphene oxide composite microspheres (MGO) were firstly synthesized via one step miniemulsion polymerization. α-FeOOH rods were then loaded onto MGO via a facile hydrothermal method to prepare α-FeOOH@MGO, which was served as the photocatalyst for the Fenton reaction. Subsequently, the properties of the resulting α-FeOOH@MGO were characterized by FT-IR, XRD, SEM, VSM and UV-vis DRS analysis methods. The influence of various parameters was investigated, such as dye type, dye concentration, H2O2 dosage, catalysts dosage and pH of MO solution during heterogeneous photo-Fenton processes. Under visible light irradiation, the degradation rate of MO, MB and CR could reach 99.96%, 98.47% and 99.97% in 40 min, respectively. Six cycle experiments confirmed that the α-FeOOH@MGO possessed a satisfied stability and recycling ability. In addition, the photocatalytic reaction mechanism was also revealed by the Mott-Schottky plot, band structure and trapping experiments of active species. [ABSTRACT FROM AUTHOR]

In this work, cobalt activated TiO2 photocatalyst have been successfully prepared on graphene oxide (GO) using simple and cost‐effective method to prepare Co‐TiO2/GO nanocomposites for the photocatalytic treatment of methylene blue (MB), representative organic dye, under visible light irradiation. The as‐prepared samples were characterized by X‐ray diffraction (XRD), High resolution transmission electron microscope (HRTEM), X‐ray photoelectron spectroscopy (XPS), UV‐vis diffused reflectance spectra (DRS), Raman spectroscopy and photoluminescence spectroscopy (PL). The characterization results confirmed that Co‐TiO2 catalyst is decorated on the graphene oxide. The photocatalytic efficiency of Co‐TiO2/GO for the degradation of MB was also improved by changing the proportion between Co‐TiO2 and GO. Highest photocatalytic activity was observed for Co‐TiO2 loaded with 5 wt % GO (88.7 %) compared with neat Co‐TiO2 (43.4 %) after 180 min of visible light irradiation. Furthermore, degradation by products was analyzed on Quadrupole Time‐of‐Flight Liquid Chromatography/Mass Spectroscopy (QTOF/LCMS) and the possible degradation pathway was proposed. It is investigated that the Co‐TiO2/GO nanocomposite has potential use in the catalytic degradation of organic contaminants under visible light irradiation. [ABSTRACT FROM AUTHOR]

Remediation of organic dyes from wastewater in textile industries is a big challenge to decreasing water pollution. This study was aimed at the preparation of ZnO nanoparticles (NPs) and their application as a photocatalyst for the degradation of methylene blue (MB), sunfix red (SR) and real textile wastewater (RTW) under both UV and visible irradiations. The ZnO NPs were synthesized with a green Thymus vulgaris leaf extract-supported approach following the calcination process. 50 mg L−1 MB and 50 mg L−1 SR dyes were completely photodegrade under UV irradiation after only 20 and 45 minutes, respectively, in the presence of 1.0 mg/mL ZnO NPs. When they are exposed to visible light, the degradation efficiency reached 91 and 75% within 60 and 120 min, respectively. Photocatalytic measurements of RTW depict that 95% (within 60 min under UV illumination) and 79% (within 90 min under visible illumination) were degraded, respectively. The enhanced photodegradation can be attributed to the narrowing of the bandgap of the ZnO NPs, high crystallinity and nearly hexagonal morphology with an average size of 20–30 nm. The present results show that ZnO NPs could potentially be applied for high-efficiency degradation of organic dyes and RTW under both UV and visible light irradiation. We report for the first time, Thymus vulgaris leaf extract–assisted synthesis of ZnO nanoparticles (NPs) has been applied as a photocatalytic dye and RTW degradation. Second, our synthesis approach is more facile and simple than the previous method where complex hydrothermal or solvothermal methods have been applied, which leads to a complex preparation procedure. We systematically prepared ZnO materials in taking account into the variable Thymus vulgaris/ZnO precursor ratio, different calcination temperature and time and in detail, their photocatalytic activity has been fully investigated. [ABSTRACT FROM AUTHOR]

This is due to the fact that TiO2 has the wide energy gap and short life and its photocatalytic active only under ultraviolet light, and so its application is greatly limited. TiO2 can form a heterojunction if combined with other semiconductors to enhance its photocatalytic ability under visible light. In this study, a TiO2/Bi2SiO5 photocatalyst with n–n heterojunction was successfully synthesized by the sol–gel method and hydrothermal method. Eggshell waste has long been used as fertilizer to grow plants or food additives for livestock, or as an adsorbent in metal ions and organic dyes. Using eggshell as a carrier of photocatalyst can possibly reduce its cracking of the substrate. The photocatalyst was deposited on eggshell powder by solid state dispersion (SSD). It was analyzed for the adsorption and degradation of methylene blue by various compositions of the photocatalysts and eggshell powder under visible light. The results demonstrated that the ratio of TiO2/Bi2SiO5: eggshell powder at 1:1 could have the best removal ability. To better facilitate the recovery of the photocatalyst from the aqueous solution, we used the techniques of electrostatic spraying and electrospinning to prepare nylon 6,6 nanofiber membranes with various composite photocatalyst (TiO2/Bi2SiO5/Eggshell/Nylon 6,6 NFM). The nanofiber membrane degraded 98% of methylene blue after 30 min of dark adsorption and 1 h of visible light irradiation. [ABSTRACT FROM AUTHOR]

[Display omitted] The exploration of emerging photocatalysts like covalent organic frameworks (COFs) is an essential but challenging endeavor to find sustainable solutions for selective organic transformations. Anthraquinones are envisaged to construct COFs for visible light photocatalysis because their derivatives are employed industrially as oxidation catalysts or organic dyes. Herein, an anthraquinone COF, TpAQ-COF, is successfully constructed with 1,3,5-triformylphloroglucinol (Tp) and 2,6-diaminoanthraquinone (AQ). Then, the selective oxidation of amines over TpAQ-COF is implemented. Amines can be effectively converted into corresponding imines over TpAQ-COF powered with green light and oxygen, during which superoxide radical anion is discerned as the pivotal reactive oxygen species. This work suggests that COFs could inherit the advantages of molecular building blocks for selective reactions powered with broad visible light. [ABSTRACT FROM AUTHOR]

Ag-ZnO/MWCNT composites were obtained by microwave-assisted, varying-charge synthesis of multiwalled carbon nanotubes (MWCNT). The structural, morphological and optical properties were characterized by: XRD, SEM, TEM, Physisorption of N2 and UVVis. The incorporation of Ag ions and MWNTC caused changes in the structure tension and in the average crystallite size of ZnO. The micrographs revealed that ZnO agglomerates were distributed on the MWNTC and that Ag particles were deposited on the surface of the heterostructure, thus the energy gap decreased. The percentages of degradation of methylene blue were 98 and 75% under ultraviolet and visible radiation, respectively, in the Ag-ZnO/CNT composites. [ABSTRACT FROM AUTHOR]

In the past decades, great efforts have been made to develop novel visible‐light photocatalysts to achieve high photocatalytic efficiency by utilizing visible light, the largest proportion of solar energy. As a new type of photocatalyst materials, all‐inorganic lead‐free halide double perovskites have begun to attract widespread interest. Herein, double perovskite Cs2AgBiCl6 was developed into a visible‐light photocatalyst for degrading organic dyes. Cs2AgBiCl6 was prepared by the hydrochloric acid precipitation and anti‐solvent recrystallization methods, respectively, and was used to degrade organic dyes under visible light. Samples prepared by the anti‐solvent recrystallization method are smaller than those prepared by the hydrochloric acid precipitation method, which can degrade 95.7 % of Sudan III in 10 min and show excellent photocatalytic activity. The cyclic experiments demonstrate that Cs2AgBiCl6 has a good cycle stability. Moreover, Cs2AgBiCl6‐AS also exhibits good photocatalytic degradation ability for Methyl red and Malachite green. These distinctive results indicate that Cs2AgBiCl6 may be a promising material for developing novel, high‐efficient and stable visible‐light photocatalysts. [ABSTRACT FROM AUTHOR]

To simulate natural photosynthesis, scientists have developed an artificial Z-scheme system that splits water into hydrogen and oxygen using two different semiconductors. Researchers are striving to improve the performance of Z-scheme systems by improving light absorption, developing redox couples with high stability, and finding new cocatalysts. Here, we report the synthesis and utilization of LaFeO3/g-C3N4 as a Z-scheme system for water reduction to produce hydrogen and organic dye degradation under visible light irradiation. The as-fabricated photocatalyst revealed exceptional activity for H2 production (i.e., 351 µmol h−1g−1), which is 14.6 times higher compared to that of the single-component g-C3N4 (i.e., 24 µmol h−1g−1). In addition, the composite photocatalyst degraded 87% of Methylene Blue (MB) and 94% of Rhodamine B (RhB) in 2 h. Various experimental analyses confirmed that the exceptional performance of the LaFeO3/g-C3N4 Z-scheme catalyst is due to remarkably enhanced charge carrier separation and improved light absorption. The development of this highly effective Z-scheme heterostructure photocatalyst will pave the way for the sustainable development of newly designed Z-scheme scheme systems that will tackle energy and environmental crises. [ABSTRACT FROM AUTHOR]

In this work, α-MnO 2 /BiVO 4 nanocomposites with varying MnO 2 contents (0–7 wt%) were successfully prepared via the simple chemical method. The structure, morphology, and optical properties of prepared nanocomposites were studied by various analytical techniques including X-ray diffraction (XRD), scanning electron microscopy (SEM), UV–visible absorption spectroscopy, and photoluminescence (PL) spectroscopy. The photocatalytic efficiency of α-MnO 2 /BiVO 4 nanocomposites was studied via decomposition of rhodamine B (RhB) and tetracycline (TC) under exposure to visible light (λ ≥ 420 nm). Due to good structure and composite advantages, 5%MnO 2 /BiVO 4 (MnBV-5) photocatalyst exhibited superior RhB and TC degradation efficiency to all other samples. In addition, the MnBV-5 photocatalyst showed good stability, and no apparent reduction in photocatalysis efficiency was noted after five testing cycles. Therefore, the MnO 2 /BiVO 4 nanocomposite demonstrated a good potential for photocatalytic decomposition of new water contaminants. [ABSTRACT FROM AUTHOR]

Photocatalytic degradation of organic dyes in less-toxic products under visible light irradiation is considered a green method which is widely used in this field. In this manuscript, a novel coordination polymer (PUCP1) based hybrid-nanocomposite (PUCP1@rGO) was synthesized. The PUCP1 and nanocomposite were successfully characterized by using various analytical techniques such as SCXRD, FT–IR, PXRD, TGA, FE–SEM, BET and XPS. The PUCP1 exhibits a 2D framework with an uninodal 4-connected net and sql topology. The PUCP1@rGO was applied as a sensitive and selective photocatalyst for significant degradation of Safranin-O (SO) dye. The rGO played an important role in the expansion of photocatalytic activity of the PUCP1 by inhibiting the recombination probability of electron–hole pairs. The results revealed that PUCP1@rGO nanocomposite can degrade 76% of SO dye in only 90 min under visible light at a neutral pH. The PUCP1@rGO was found very sensitive to photocatalytic degradation of SO dye because a very small amount of catalyst (i.e. 10 mg) degrades the 5 μM concentration of SO dye in the presence of light. The PUCP1@rGO is a reusable photocatalyst for up to 5 cycles. Rarely, any sensitive photocatalyst for SO dye is reported in literature than PUCP1@rGO which degrades SO dye in a very small period with significant quantity. Thus, PUCP1@rGO can be used as a promising photocatalyst for the degradation of SO dye. In this work, we have synthesized a novel coordination polymer (PUCP1) and nanocomposite (PUCP1@rGO) by impreganation of rGO in PUCP1 framework.The PUCP1 exhibited selective photocatalytic response towards safranin-O dye under visible light irradiation and impregnation of rGO enhance the photocatalytic properties of PUCP1@rGO nanocomposite as compared to parent PUCP1.The PUCP1@rGO nanocomposite degrade the safranin-O dye up to 76% in 90 min only under visible light. [ABSTRACT FROM AUTHOR]

A novel series of the heterojunctions g‐CN/BBO(x) of g‐C3N4 (g‐CN) nanosheets decorated with spherical particles of BaBiO3 (BBO) were designed to enhance photocatalysis through interfacial charge transfer. The synthesized g‐CN/BBO(x) nanocomposites were characterized by various techniques such as XRD, FTIR, TEM, and SEM. Rhodamine B (RhB) dye and diclofenac sodium drug were taken as the model pollutants for the degradation under visible light. BBO facilitates the photocatalytic reaction after accepting electrons from the g‐CN. The g‐CN/BBO(30%) nanocomposite exhibits the best photocatalytic activity, which is 6.5 and 5 times higher than BBO and g‐CN, respectively. The enrichment in photodegradation is attributed to the combined effects of improved dye adsorption, visible light absorption, mobility of photogenerated carriers, and facial separation of electrons and holes (e−, h+) as supported by electrochemical impedance spectroscopy (EIS). This study provides new insight into the engineering, design, and stability of the g‐CN/BBO(x) heterojunction nanocomposite, as well as on its application and plausible mechanism for removal of harmful and detrimental pollutants such as RhB dye and diclofenac sodium drug under visible light. [ABSTRACT FROM AUTHOR]

Designing of an effectual heterostructure photocatalyst for catalytic organic pollutant exclusion has been the subject of rigorous research intended to resolve the related environmental aggravation. Fabricating p-n junctions is an effective strategy to promote electron-hole separation of semiconductor photocatalysts as well as enhance the organic toxin degradation performance. In this study, a series of n-type NiAlFe-layered triple hydroxide (LTH) loaded with various ratios of p-type MoS 2 was synthesized for forming a heterostructure LTH/MoS 2 (LMs) by an in situ hydrothermal strategy. The photocatalysts were characterized by XRD, SEM&EDX, TEM, FT-IR, XPS, as well as UV–vis DRS. The photoactivity of photocatalysts was tested by the degradation of Indigo Carmine (IC) dye. The optimized catalyst (LM1) degrades 100% of indigo dye in high alkaline pH under UV light for 100 min. Besides, the degradation rate of LM1 is 15 times higher than that of pristine NiAlFe-LTH. The enhanced photoactivity is attributed to the synergistic effect between NiAlFe-LTH and MoS 2 as well as the p-n junction formation. [Display omitted] • A facile method for synthesizing heterostructure-LMs photocatalyst is suggested. • The best photocatalytic performance was found in LM1 samples for dye degradation. • Superior adsorptive-photocatalytic activity of LM1 was revealed under visible light. • Photocatalytic performance of LMs was effectively exhibited even at high pH over 11. • The recyclability and mechanism of photocatalysis of LMs was identified. [ABSTRACT FROM AUTHOR]

• Preparation of pure ZnO and new Li-doped ZnO, Ag-doped-ZnO and Ag-Li doped ZnO nanocomposites materials by sol-gel method and thoroughly characterized. • Photodegradation of organic dye pollutants such as acid red-1 and mordant orange-1dyes and textile wastewater under visible light irradiation. • Mechanistic studies established that the active species are hydroxy radials via several scavengers' studies. The study describes the preparation and characterization of pure ZnO, Li-ZnO (LZO), Ag-ZnO (AZO) and Ag-Li-ZnO (ALZO) nanostructures by sol-gel method, followed by their application as photocatalysts for the degradation of dyes acid red (AR1), mordant orange (MO1) and textile wastewater (TWW) under irradiation of visible light. The ALZO composite showed the highest photocatalytic efficiency among the tested samples with 95% degradation of dyes, which was three times higher than that of pure ZnO. The degradation reaction followed pseudo-first-order kinetics and the control trapping experiments corroborated the reactive species are hydroxyl radicals. The study also investigated the influence of various operational parameters on the photodegradation of dyes. The high photocatalytic efficiency of the ALZO material is mainly due to its highly porous structure with greater surface area, enhanced absorption of visible light, and a decreased recombination rate of electron-hole pairs. The ALZO catalyst had a band gap energy of 2.82 eV and exhibited the wurtzite ZnO hexagonal phase. The study highlights the effectiveness of doping metal oxides into semiconductor oxides to enhance photocatalytic activity and suggests the potential of the ALZO composite as a promising photocatalyst for dye degradation. [ABSTRACT FROM AUTHOR]

Water, the most fundamental source of life, is contaminated by various organic pollutants, especially organic dyes from the dying industry. The photocatalytic degradation of malachite green (MG) was studied using a zinc-based metal-organic framework (Zn-BTC MOF) and ZnO. Thermally decomposing Zn-MOF synthesized ZnO and its structural and optical properties were analyzed using various spectroscopic techniques. This article focuses primarily on the wavelength-dependent photoluminescence properties of Zn-MOF and ZnO materials and their role in the photocatalytic degradation of MG dye in water. Zn-MOF and ZnO photocatalysts exhibited a photodegradation efficiency of approximately 99% after 40 min of visible light exposure. Based on kinetic experiments, the degrading efficiency of these catalysts followed pseudo-first-order reaction kinetics with a correlation of R2 = 0.99 and a rate constant of 0.031 min−1. This manuscript is helpful to researchers working on ZnO and Zn-MOF materials for photocatalytic and environmental applications. • Photoluminescence is an important and frequently reported property of Metal-Organic Frameworks (MOFs). • This communication is primarily concerned with the luminescence properties of Zn-MOF and ZnO materials. • Zn-MOF and ZnO role in the photodegradation of recalcitrants such as malachite green (MG) in water. • These catalysts displayed photodegradation efficiency of about 95% within 40 min. [ABSTRACT FROM AUTHOR]

Wastewater containing organic dyes is harmful to the ecological environment and human health. Graphitic carbon nitride (g-C 3 N 5) is suitable for the photocatalytic degradation of organic dyes, but its photocatalytic activity is low due to several drawbacks. A series of Ag–CeO 2 /g-C 3 N 5 composites with different morphologies of Ag–CeO 2 have been prepared in order to improve the photocatalytic activity of g-C 3 N 5. The photocatalytic activities of the Ag–CeO 2 /g-C 3 N 5 composites were investigated using rhodamine B (RhB) as the target pollutant. When compared with Ag–CeO 2 spheres and g-C 3 N 5 , the charge separation efficiency and photocatalytic activity of the Ag–CeO 2 /g-C 3 N 5 heterostructure were significantly improved. The photodegradation rate of RhB using 50 wt% Ag (1.50)-CeO 2 (sphere)/g-C 3 N 5 was 96.5 %, while pure g-C 3 N 5 and Ag (1.50)-CeO 2 spheres was 30.8 and 9.9 %, respectively. This was attributed to the synergistic effect of the heterojunction comprised of Ag, CeO 2 , and g-C 3 N 5. As an electronic medium, Ag transfers electrons between g-C 3 N 5 and CeO 2 , which can promote electron-hole separation and improve the photocatalytic activity. The 50 wt% Ag (1.50)-CeO 2 (sphere)/g-C 3 N 5 composites also had fair photocatalytic stability and · O 2 − plays a dominant role in the RhB photodegradation process. In addition, the photocatalytic mechanism of 50 wt% Ag (1.50)-CeO 2 (sphere)/g-C 3 N 5 has also been described. [Display omitted] • Series Ag–CeO 2 /g-C 3 N 5 composites were synthesized with respective morphologies of Ag–CeO 2. • Loading Ag–CeO 2 on g-C 3 N 5 can improve the specific surface area and photocatalytic property. • The photodegradation to RhB of 50 wt% Ag–CeO 2 /g-C 3 N 5 composites can reach 96.5 % within 150 min. • The 50 wt% Ag–CeO 2 /g-C 3 N 5 composites have good photocatalytic activity and chemical stability. [ABSTRACT FROM AUTHOR]

In pursuit of the appropriate method for complete removal of organic effluents from surface water, Ag modified g-C 3 N 4 materials as a photocatalyst gained considerable attention. In this paper, Ag doped g-C 3 N 4 materials were prepared by a facile one-pot pyrolysis method. The synthesized photocatalysts were studied using different analytical techniques like XRD, HR-TEM, XPS, UV, FTIR, PL spectroscopy, etc. The prepared photocatalyst materials were used for the visible light photodegradation of IC dye as an organic pollutant and for self-cleaning applications. The obtained results indicate that the optimized Ag doped g-C 3 N 4 (CNA-1) sample exhibits 79.97 % degradation efficiency in 30 min with efficient self-cleaning performance. The enhanced photocatalytic activity of CNA-1 can be attributed to the incorporation of Ag, which plays a pivotal role in absorbing visible light. Furthermore, cycling tests were employed to evaluate the stability and reusability of material. The possible photocatalytic mechanism was proposed from trapping experiments. [Display omitted] [ABSTRACT FROM AUTHOR]

In this work, we have synthesized MoS2 nanosheets (NSs) through hydrothermal as well as liquid-phase sonication methods and studied their ability to degrade organic dyes, methyl red (MR) and methylene blue (MB) under visible light irradiation. The as-synthesized photocatalysts have been characterized by powder X-ray diffraction, Raman Spectroscopy and transmission electron microscopy to confirm their structure and surface morphology. XRD patterns show that crystalline nature of MoS2 NSs prepared by hydrothermal method appears at 160°C for 15 h. In contrast, sharp and intense diffraction peaks appear for liquid exfoliation method even at room temperature, exhibiting better crystallinity of the as-prepared NSs. The difference (∆) of ~25 cm−1 between E12g and A1g modes of Raman spectra indicates formation of 5–6 layers of MoS2 from both the synthesis routes. UV–Vis spectroscopy has been utilized to study the degradation of dyes by MoS2 NSs as catalyst. Hydrothermally assisted synthesis of MoS2 NSs exhibit lesser degradation efficiency with 58.92% for MR and 49.28% for MB, while exfoliation-assisted MoS2 NSs act as better photocatalyst with 63.40 and 62.40% degradation of MR and MB, respectively. Faster degradation rate for MR compared to MB has been attributed to the presence of lesser chromophoric sites in MR. [ABSTRACT FROM AUTHOR]

Ti 3 C 2 MXenes were constructed via different strategies using HF-forming etchants or HF as etchants and were subsequently modified through alkalization to replace –F with O-containing terminal functional groups. Various analytical techniques were used to fully characterize all fabricated materials for confirming the formation of species with the desired morphologies and properties. ML-Ti 3 C 2 , etched with HF, presented a multilayered structure that made it resemble an accordion, while DL-Ti 3 C 2 , prepared using HF-forming etchants, was not completely etched, with some amounts of the parent compound's Al remaining in unformed vague laminated structures. ML-Ti 3 C 2 alkalization yielded ML-Ti 3 C 2 (OH) 2 , which was characterized by large amounts of O-containing functional groups and greatly enhanced porosity compared with that of ML-Ti 3 C 2. Methylene blue (MB) adsorption and photocatalytic degradation tests were then conducted to evaluate the functionalities of ML-Ti 3 C 2 (OH) 2 by putting it into direct application instead of being used as catalyst promoters. ML-Ti 3 C 2 (OH) 2 achieved adsorption–desorption equilibrium using MB in the dark within 30 min and 81.2% of MB was then selectively degraded over 120 min under simulated visible light irradiation. A possible degradation mechanism was proposed on the basis of the results of radical quenching experiments. This study offers a unique mechanism for directly applying MXene to the adsorption–photocatalytic degradation of organics in wastewater. For Preparation and regulation of two-dimensional Ti 3 C 2 T x MXene for enhanced adsorption-photocatalytic degradation of organic dyes in wastewater. [Display omitted] [ABSTRACT FROM AUTHOR]

Graphitic carbon nitride (g-C3N4) is a metal-free photocatalyst with visible light response. However, the disadvantages limit its application in a wider range, such as its small specific surface areas, fewer active sites, narrow visible light absorption range and high photogenic carrier recombination. In this paper, NaOH was used as an activator for alkaline activation of g-C3N4. The phase composition, micromorphology, surface chemical state and optical properties of g-C3N4 after activation were tested. The photocatalytic performance of g-C3N4 over organic dyes was also tested. The results showed that Na+ entered the interlayers of g-C3N4, expanding the spaces between layers. The specific surface area and pore volume of powder were increased. The active sites were increased. The band gap was decreased, and the photogenic carrier recombination was reduced. Alkaline activated g-C3N4 had better adsorption and degradation performance over rhodamine B and methyl orange than inactivated g-C3N4. Therefore, the alkaline activated g-C3N4 promotes its further application in the field of wastewater treatment. This work sheds light on the material modification through a simple method with the aim to efficiently use solar energy. [ABSTRACT FROM AUTHOR]

Ethynylbenziodoxolones (EBXs) are commonly used as radical traps in photocatalytic alkynylations. Herein, we report that aryl‐substituted EBX reagents can be directly activated by visible light irradiation. They act as both oxidants and radical traps, alleviating the need for a photocatalyst in several reported EBX‐mediated processes, including decarboxylative and deboronative alkynylations, the oxyalkynylation of enamides and the C−H alkynylation of THF. Furthermore, the method could be applied to the synthesis of alkynylated quaternary centers from tertiary alcohols via stable oxalate salts and from tertiary amines via aryl imines. A photocatalytic process using 4CzIPN as an organic dye was also developed for the deoxyalkynylation of oxalates. [ABSTRACT FROM AUTHOR]

Ethynylbenziodoxolones (EBXs) are commonly used as radical traps in photocatalytic alkynylations. Herein, we report that aryl‐substituted EBX reagents can be directly activated by visible light irradiation. They act as both oxidants and radical traps, alleviating the need for a photocatalyst in several reported EBX‐mediated processes, including decarboxylative and deboronative alkynylations, the oxyalkynylation of enamides and the C−H alkynylation of THF. Furthermore, the method could be applied to the synthesis of alkynylated quaternary centers from tertiary alcohols via stable oxalate salts and from tertiary amines via aryl imines. A photocatalytic process using 4CzIPN as an organic dye was also developed for the deoxyalkynylation of oxalates. [ABSTRACT FROM AUTHOR]

The layered Bi3O4Br nanoplates were synthesized through a simple calcination process, which can simultaneously harvest visible light and ultrasonic vibration to realize the effective piezo-photocatalysis. The piezo-photocatalysis over the Bi3O4Br leads to a great enhancement in catalytic efficiency with respect to the pure photocatalysis or piezocatalysis. The apparent rate constant of piezo-photocatalysis for the degradation of MO achieves to be 0.008 min − 1 , which is 5.20 and 1.51 times as high as the individual piezocatalysis and photocatalysis, respectively. This enhancement would be attributed to the built-in piezoelectric field induced by ultrasonic vibration facilitating the separation of charge carriers in photoexcited Bi3O4Br. [ABSTRACT FROM AUTHOR]

• Using cheap ethanolamine as raw material, an ingenious strategy was employed to prepare the Fe-and-N co-doped ZIF-derived catalyst, which not only effectively avoided the aggregation of active species, but also was conducive to spread application and promotion. • The dimension of nanostructure for the series catalysts are all uniform and small (∼100 nm), and it can still do plenty of advantages to the catalytic activity. • The highly uniform dispersed of Fe and N active sites not only broadens the visible light response range, but also greatly improve the photocatalytic performance of the materials, and almost 100% of the dyes were removed in just 25 min. The amino and iron modified Metal-organic frameworks was successfully synthesized via a skillfully strategy and used as a photocatalyst to decompose organic dyes under visible light irradiation. Results show that 50 mg catalyst can almost degrade 100% MB within just 25 min at a wide pH (3.4–11.9) range. The kinetics constant (k) on Fe-ZIF-8-NH 2 (1/10) is estimated to be 0.0896 min−1, significantly higher than control samples. Meanwhile, there is little effect of various water sources on catalytic activities, and the rate reaches 97.1% (in Tap water), 88.5% (in Yangtze River water) and 78.1% (in oilfield brine with ultrahigh mineralization). Besides, the Fe-ZIF-8-NH 2 (1/10) exhibits high stability after 5 cyclic runs, and the ICP detects a small amount of Fe3+ (0.153 mg/L) leaching. Characterization reveals the catalyst has hierarchical porous structure, a rather homogeneous geometric topology and uniformly dispersed active sites. Based on the N 1 s spectrum of XPS, the nitrogen group is successfully loaded in amino mode. Its band gap drops sharply from 5.11 eV to 2.17 eV and the peak of PL spectra is much smaller, and the Fe-ZIF-8-NH 2 (1/10) possesses stronger absorption in visible light region and the response wavelength is widened to 700 nm. Further, the possible mechanism of photocatalytic degradation of pollutants is also proposed. The h+ is the most effective active species, meanwhile, •O 2 − , e − and •OH are both apparently participated in the photodegradation process. This study introduces valuable information for constructing high active catalysts on administration of water pollution. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • TiO 2 with high exposure of (001) facet can be fabricated using solvothermal method. • Ultrasonic method was used to efficiently prepare TiO 2 (001)/GO composite. • Integration of GO and TiO 2 (001) successfully increased photoactivity of the material. • Methylene blue and crystal violet were efficiently photodegraded at visible range. • The exposure of TiO 2 ′s (001) was responsible for the enhancement of photoactivity. Photodegradation has been considered one of the most promising ways to treat wastewater. In this work, TiO 2 (001)/Graphene Oxide (GO) nanocomposite has been successfully synthesized using hydrogen fluoride as a crystal-directing agent towards (001) facets. The nanocomposite was characterized by FTIR, XRD, Raman, HR-TEM, and diffuse reflectance spectra (DRS). Based on the result, the TiO 2 (001) was decorated on the surface of the GO sheet with high absorption of visible light. In addition, as-prepared TiO 2 (001)/GO nanocomposite provides a synergistic effect by increasing dye degradation activity with 95% and 99% removal rates for the photodegradation of methylene blue and crystal violet dyes, respectively, under LED irradiation for 10 min. The photodegradation kinetics of TiO 2 (001)/GO was also successfully modeled and was found to follow the pseudo-first order kinetic. The enhanced photodegradation of the TiO 2 (001)/GO nanocomposite attributed to the excellent synergy between TiO 2 (001) nanoparticles and GO, which results in the highly efficient photocatalyst for removing organic pollutants in water. [ABSTRACT FROM AUTHOR]

[Display omitted] • Flower-like Cu-doped In 2 S 3 was constructed through a one-step hydrothermal method. • Cu-doping enhanced visible-light response and BET surface area of In 2 S 3. • Cu-doped In 2 S 3 exhibited excellent adsorption and catalytic degradation activity of Rhodamine B. • Superoxide ion radical was the main active substance in initiating the degradation of Rhodamine B. In 2 S 3 materials doped with different concentrations of copper ions (Cu-In 2 S 3) were designed and synthesized, which successfully improves the response to visible light, separation of carriers, and adsorption for rhodamine B of In 2 S 3. Cu-doping improves the photocatalytic activity of In 2 S 3 for dye removal. In 2 S 3 doped with 0.3% Cu2+ exhibits the highest photocatalytic activity for the degradation of rhodamine B. In addition, it shows high photocatalytic stability. The photocatalytic active species capture experiments show that the superoxide radical was the main active substance for the photocatalytic degradation of rhodamine B over 0.3% Cu-In 2 S 3. This study provides a valuable reference for the construction of In 2 S 3 -based photocatalytic materials. [ABSTRACT FROM AUTHOR]

This work aims to demonstrate that micronized β-cyclodextrin (β-CD) improves the photocatalytic activity of Fe-N-TiO 2. Fe-N-TiO 2 /β-CD hybrid systems were employed in the photocatalytic removal of Acid Orange7 (AO7) and Methylene Blue (MB). The supercritical antisolvent process (SAS) was used to micronize β-CD at different pressures. The chemical-physical properties of the hybrid photocatalysts were detected through various characterization methods. Wide angle X-ray diffraction patterns evidenced the anatase as the typical TiO 2 crystalline phase. FT-IR spectra showed interactions between β-CD and Fe-N-TiO 2. The activity of photocatalysts in the degradation of AO7 and MB dyes was analyzed under UV and visible light irradiation. Fe-N-TiO 2 /β-CD120 photocatalyst led to the total UV light-driven discoloration of the AO7 aqueous solution. Instead, the Fe-N-TiO 2 /β-CD120 system allowed for achieving an MB discoloration kinetic constant under visible light higher than the AO7 discoloration kinetic constant. Reuse cycle tests proved that the Fe-N-TiO 2 /β-CD120 sample is a stable photocatalytic material. [Display omitted] • SAS process to obtain β-cyclodextrin sub-microparticles. • Fe-N-TiO 2 /β-CD stable and reusable photocatalyst was prepared. • Complete color removal from aqueous solutions containing AO7 under UV light. [ABSTRACT FROM AUTHOR]

A novel bismuth vanadate–silicon dioxide–graphene oxide (BiVO4/SiO2/GO) nanocomposite was synthesized successfully by using hydrothermal method. The as-prepared nanocomposite was characterized by various techniques, including X-ray diffraction (XRD), field emission scanning electron microscope (SEM), and Brunauer–Emmett–Teller (BET). The photocatalytic activity of nanoparticles was evaluated by measuring the removal efficiency of methylene blue (MB) in aqueous solution under visible light irradiation. The results indicated that BiVO4, BiVO4/SiO2, and BiVO4/SiO2/GO exhibited the same diffraction peaks of monoclinic scheelite structure due to the higher content of BiVO4 in the nanocomposite system. The BiVO4 and BiVO4/SiO2 were uniformly agglomerated from irregular particles with the different level of aggregation and the size of several micrometers. In the meantime, BiVO4 and SiO2 particles were adhered firmly on the GO sheets in BiVO4/SiO2/GO nanocomposite. The BiVO4/SiO2/GO nanocomposite showed a much higher efficiency than the pure BiVO4 and the BiVO4/SiO2 hybrid material for MB removal efficiency due to the considerably increased specific surface area and pore size by the adhesion of BiVO4 and SiO2 on GO sheets. [ABSTRACT FROM AUTHOR]

Environmental problems caused by the influence of organic dyes have devoted researchers to build the system for the degradation of dyes. Photocatalysis has gained a remarkable interest to degrade organic dyes for wastewater treatments. In this work Polyaniline@NiO with different wt.% the composition was synthesized with rich catalytic sites by in‐situ polymerization to degrade the organic dye Rhodamine‐B from water. The synthesized materials were characterized by XRD, RAMAN spectroscopy, SEM, UV/Vis spectroscopy and Photocatalytic degradation. Polyaniline (PANI) showed a high absorption coefficient in visible light and NiO absorbs light in the ultraviolet range. The charge mobility was enhanced by making a composite of PANI and NiO. The photocatalytic performance of PANI in visible light was improved by making its composite with NiO, which provides the easing path to flow photoelectron from LUMO of PANI to the surface of the water and further dye degradation mechanism was performed [ABSTRACT FROM AUTHOR]

The g-C 3 N 4 /ZnO nanorods were prepared by simple hydrothermal, grinding and calcination methods. The characterization of g-C 3 N 4 /ZnO nanorods was done by different analytical techniques such as SEM, TEM, XRD, XPS, FT-IR and UV–Vis. g-C 3 N 4 /ZnO nanorods with heterostructures have been successfully synthesized without changing the structure between the monomers, which broadens the visible light response range and improves several major pollutants in water degradation rate. Photocatalytic studies were done for the degradation of MB, RhB, Cr(VI) and eosin which are almost fully degraded. The experimental results show that the photocatalytic performance of the nanorods is much better than others. The g-C 3 N 4 /ZnO photocatalyst has excellent stability and repeated cycle performance. Basing on the results of comprehensive free radical trapping test and ESR tests, it is proposed that the main active substance of the catalyst for degrading dyes is ·0 2 -, and ·OH played significant roles in the degradation process. A good photocatalytic mechanism has been proven. [ABSTRACT FROM AUTHOR]

• Mn or Fe doped CuO/ZnO were synthesized by co-precipitation method. • The ferromagnetism of CuO/ZnO nanocomposite enhanced by Mn and Fe doping. • Notable magnetization of 0.86 emu/g was found for 4 wt% Mn doped CuO/ZnO. • 4 wt% Mn induced superior visible light photocatalytic activity in CuO/ZnO. • Degradation efficiency of 98% with good recyclability was detected. Mn doped CuO/ZnO heterostructure exhibited significant room temperature ferromagnetism and visible light photocatalytic properties. Phase analysis for the pure, Mn and Fe doped CuO/ZnO nanocomposites evidently confirmed the formation of CuO and ZnO phases in each composite without any impurities. Based on Rietveld refinement analysis, the inclusion of Mn ions into CuO/ZnO nanocomposite decreased the unit cell volume of both oxides while Fe ions lead to lattice expansion. Mn ions induced the formation of ZnO hexagonal nanorods in CuO/ZnO nanocomposite. Nano-flakes and spherical nanoparticles shapes were seen for Fe doped CuO/ZnO nanocomposites. The characteristics IR absorption bands of CuO and ZnO overlapped together in their nanocomposites structure. From Kubelka-Munk plots, the incorporation of Mn ions enabled the ZnO band gap to absorb in the visible light region. Pure CuO/ZnO nanocomposite exhibited room temperature ferromagnetism with saturation magnetization (M s) of 0.042 emu/g and coercivity (H c) of 547 Oe. The ferromagnetic properties of the pure CuO/ZnO nanocomposite were greatly improved by Mn and Fe doping and the saturation magnetization extremely jumped to 0.86 and 0.85 emu/g, respectively. High photocatalytic activity, 98%, with good reusability for methyl orange (MO) degradation under visible light irradiation was achieved by 4 wt% Mn doped CuO/ZnO nanocomposite. A relation between the crystallinity, band gap and photocatalytic activity with dopant type (Mn or Fe) incorporated into CuO/ZnO nanocomposites was noticed. In contrary to Fe dopant, Mn as dopant played successful roles in improving the crystallinity, band gap and photocatalytic properties of CuO/ZnO nanocomposite. Multifunctional properties can be realized by combining different oxides in heterostructure form and using doping technique. [ABSTRACT FROM AUTHOR]

Photosensitization is a potential candidate for improving photocatalytic performance of inorganic semiconductors in water splitting. Given many photosensitizers are organic dyes bearing strong hydrophobicity, simple combination of dye and inorganic material, however, still suffers limited access of the photocatalyst to water and consequently presents compromised activity. Herein, we exploited aminated acid red-94 (RB-NH 2) to prepare dye chemically modified alginate (RB-NH-HA) via dialysis method, which was further employed to incorporate with CdS (RB-NH-HA@CdS). According to the water contact angles (CA water) and photoelectrochemical detection, though simply integrated CdS with RB-NH 2 (RB-NH 2 @CdS) expectantly enhanced the transient photocurrent over CdS, yet the CA water was apparently emaciated from 53.56° to 86.12°, even leading to a slightly attenuated photocatalytic performance in hydrogen evolution under visible light. In contrast, introducing hydrophilic HA into RB-NH-HA@CdS is able to reclaim the CA water to 50.22°. Moreover, owning to the cooperative effects proffered by the significantly increased contacts between the reactant (H 2 O) and the composite, as well as the fluorescent feature that improves the photocatalyst's visible-light absorption and simultaneously suppresses the recombination of photo-induced carriers, the hydrogen production rate was advanced to 475 μmol·h−1 H 2 , about 4.5 and 5.7 times that of CdS and RB-NH 2 @CdS, respectively. Our work provides an efficient method to ameliorate the sensitization technique aiming to improve the photocatalytic performance of inorganic semiconductors. An alginate-based polymer could effectively photosensitize CdS and present enhanced photocatalytic hydrogen evolution due to its improvement in wettability of the structure. Unlabelled Image • The hydrophilic alginate-based polymer RB-NH-HA was employed to improve the wettability of RB-NH 2 @CdS. • The RB-NH-HA takes dual effects of water miscibility and optical feature on the photocatalytic performance. • RB-NH-HA@CdS can give the hydrogen production rate of 475 μmol•h-1, about 4.5 times that of CdS. [ABSTRACT FROM AUTHOR]

• Prepared composite nanofiber membrane possesses a good photocatalyst performance. • High degradation activity of organic dyes under visible light. • The composite nanofibers membrane possessed excellent recovery and reuse. • The free-standing membrane is flexible and easy to handle. • The flexibility of the composite nanofibers allows use in a continuous operation. This study proposed an effective method by using photocatalytic composite nanofiber membranes in order to degrade malachite green (MG) and acid red 27 (AR 27) to harmless products. The photocatalytic composite nanofiber membrane, Polyacrylonitrile (PAN) was incorporated with catalyst SiO 2 and TiO 2 photocatalyst. The PAN/SiO 2 -TiO 2 -NH 2 nanofiber membrane was synthesized by electrospinning technique followed by chemical crosslinking. The results of SEM, EDX, FTIR and XRD confirmed the successful preparation of nanofiber membrane. XRD analysis shows the confirmation of SiO 2 and TiO 2 peaks. The result shows that PAN/SiO 2 -TiO 2 -NH 2 nanofiber membrane exhibit the highest degradation with a good distribution of SiO 2 and TiO 2 on the PAN nanofiber membrane surface. The results showed that the complete photodegradation of MG and AR 27 with artificial visible-light was achieved after 9 and 25 min, respectively. In addition, the nanofiber membrane exhibited good stability and reusability for MG and AR 27 photodegradation and has potential to be applied in industrial application. [ABSTRACT FROM AUTHOR]

In this paper, MoS 2 was used as a band-suitable semiconductor to construct the Bi 2 O 3 /MoS 2 heterostructured photocatalysts for the first time via a deposition-hydrothermal method. The XRD, SEM and HRTEM analysis indicated that the surface of Bi 2 O 3 was decorated with MoS 2 nanoparticles and Bi 2 O 3 /MoS 2 heterojunctions were formed. The performances on photocatalytic degradation of methylene blue (MB) and tetracycline (TC) were evaluated under visible light irradiation. The results demonstrated that the Bi 2 O 3 /MoS 2 heterojunctions displayed remarkably improved photocatalytic activity for both MB and TC degradation, compared to the base material (Bi 2 O 3). Specifically, as the molar ratio of MoS 2 was 23.81%, the obtained Bi 2 O 3 /MoS 2 -23.81 heterojunctions exhibited promising photocatalytic activities, and approximately 100% MB and 97% TC were degraded within 100 min, respectively. The superior photocatalytic activity was mainly attributed to its large surface area, high visible-light harvesting and the efficient separation of photogenerated electrons and holes caused by the unique heterojunction architecture. Notably, the Bi 2 O 3 /MoS 2 heterojunctions showed remarkable stability in recycling photocatatlytic experiments. The active species trapping and terephthalic acid (TA) fluorescence experiments indicated that the •OH was the major reactive oxidizing species for MB degradation. Furthermore, the intermediates were detected by UPLC-MS spectrometry and the possible degradation pathways for MB and TC were proposed. Finally, a possible reaction mechanism of Bi 2 O 3 /MoS 2 heterojunctions for the photodegradation MB was also proposed. This interesting interfacial architecture strategy will provide useful insights for designing and fabricating new class of binary heterojunctions with high-efficient photocatalytic activity towards practical application. A highly efficient visible-light responsive photocatalyst Bi 2 O 3 /MoS 2 heterojunctions was prepared for the organic dyes and antibiotic pollutants elimination. Image 1 • Bi 2 O 3 /MoS 2 heterojunction was prepared by deposition-hydrothermal method. • Bi 2 O 3 /MoS 2 -23.81 exhibited enhanced photocatalytic activity than that of pure Bi 2 O 3. • The electrons transfer and visible-light harvesting effects were obviously improved. • The ⋅OH was the main oxidative species of Bi 2 O 3 /MoS 2 -23.81 for the MB decomposition. [ABSTRACT FROM AUTHOR]

New polyoxometalate (POM)/polymer hybrid composites were prepared by photopolymerization under mild conditions for suitable photocatalytic processes. Polyoxometalates were incorporated in special photosensitive resins, which were photopolymerized under visible light to obtain new materials with photocatalytic activity for dye removal. The synthesized composites were characterized by real‐time FT‐IR, and the photocatalytic ability was investigated on Eosin‐Y removal using photolysis under near UV irradiation. Interestingly, the polyoxometalates keep their photocatalytic properties, while incorporated into the polymeric matrix since very high conversion rates of Eosin‐Y were achieved. Indeed, degradation efficiencies of about 98% and 93% were registered when using H3PMo12O40/polymer and 94% for SiMo12O40(IPh2)4/polymer composites, respectively. These first results reported in this article show that the new synthesized POM/polymer composites could be considered as promising materials for green and more suitable organic dye removal from aqueous solutions. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1538–1549 [ABSTRACT FROM AUTHOR]

Herein, we have realized the transformation from Cu2S to CuS phase by a facile secondary vulcanization. The CuS completely inherited the special morphology of the precursor nanocrystal, and the feature excludes the structural and dimensional influence in the study of the effects of Cu(I) and Cu(II) on photocatalytic properties. Under visible light irradiation, the photocatalytic performances of Cu2S@CT (CT, biomass carbon tube) and CuS@CT composites were examined on organic dye (methylene blue, MB) degradation and Cr (VI) reduction at different original solution pH. Both photocatalysts exhibit good photocatalytic activity under favourable conditions, which should be attributed to the high specific surface area and luxuriant active sites of the materials with special nanostructures. Moreover, the Cu2S@CT and CuS@CT show distinct‐different oxidability and reducibility due to the compositional difference, Cu2S@CT composites have better reduction properties of Cr(VI) at pH=2, while the CuS@CT composites exhibit better degradation activity of MB at pH=10. [ABSTRACT FROM AUTHOR]

• A 2D covalent organic framework Por-PD-COF as selective adsorbent and photocatalyst was designed and synthesized. • Por-PD-COF could selectively and competitively adsorb MB from the mixed organic dyes aqueous solution. • Por-PD-COF could photodegrade MB effectively under visible light. • Por-PD-COF can be recycled and reused after absorption or photocatalysis. In this work, amide bonds linked 2D porphyrin-based covalent organic framework (Por-PD-COF) was designed and synthesized through condensation reaction between meso -tetrakis (p -carboxyphenyl) porphyrin (TCPP) and para -phenylenediamine (PD). Large surface area, abundant active sites and good stability of Por-PD-COF made it can quickly and efficiently absorb methylene blue (MB) selectively and remove it from aqueous solution. More importantly, in different mixture of organic dyes including RhB and MB, MB and MO, Por-PD-COF can selectively adsorb MB with a large adsorption capacity (328.57 mg·g−1), while a little MO and hardly RhB because of the unique charge selectivity and specific pore size. Especially in the mixture solution of MO and MB, compatitive adsorption appeared, MB can substitute the adsorbed MO on the active sites in the channel of Por-PD-COF. Furthermore, with the band gap narrow to 1.02 eV, Por-PD-COF could be used as efficient photocatalyst to degrade MB (99%, 180 min) directly under visible light irradiation, and can be reused for four times with almost no absorptive and photocatalytic capacity losing. The possible adsorption and photocatalytic mechanisms of Por-PD-COF were also proposed. As a result, with the uncomplicated preparation, effective and selective adsorption and reusability, Por-PD-COF was a promising specific adsorbent and photocatalyst for further application in specific organic molecules separation and organic waste removal from aqueous solution. [ABSTRACT FROM AUTHOR]

Abstract SnS 2 exhibits lower photocatalytic activity against organic dyes without N N double bonds due to the SnIV/SnII transition which decreases its degradation efficiency due to the decreased formation of O 2 ∗ − and OH∗ radicals. To upgrade the photocatalytic ability of SnS 2 against dyes without N N bonds, NiO coupling has been adopted and the results obtained are furnished in this paper. By adopting precipitation method, SnS 2 , NiO and SnS 2 NiO nanocomposite was synthesized. Structural, morphological, compositional, functional group analyses of SnS 2 , NiO and SnS 2 NiO nanocomposite were performed by adopting techniques such as XRD, SEM, TEM, XPS, FTIR and PL. The magnetic property of pure SnS 2 got enhanced by coupling with NiO thereby making it suited for magnetic devices. Photocatalytic activities were performed against MB and RhB dyes under visible light. The enhanced degradation ability of the SnS 2 NiO composite may be due to its enhanced oxidation/reduction ability of the electrons and holes generated under the effect of visible light. Highlights • Precipitation method is used to synthesize SnS 2 NiO composite. • Magnetic property of pure SnS 2 is enhanced when coupled with NiO. • The photocatalytic activity of pure SnS 2 got enhanced by forming composite with NiO. • The SnS 2 NiO composite degraded MB better than RhB dye. [ABSTRACT FROM AUTHOR]

Abstract Here we propose new type II semiconducting nanocomposite TiO 2 /CoSe for effective separation of the photo-induced charges, thus enhancing the visible light harvesting capability of TiO 2. The formation of TiO 2 /CoSe nanocomposite is confirmed by XRD, FE-SEM, HR-TEM, XPS and BET characterization techniques. Remarkable results were obtained during photodegradation study of both Rhodamine B (99.86%) and methylene blue (97.85%) within just 90 min of visible light irradiation. The mechanistic investigation demonstrates that the Superoxide (O 2 −) radicals are most reactive species participates in photocatalytic dye degradation. The synthesized photocatalyst has good reusability, it can be successfully reused for six batches of photocatalytic reactions. Graphical abstract Unlabelled Image Highlights • Rutile TiO 2 nanorods decorated with CoSe nanoparticles. • TiO 2 /CoSe nanocomposite: a visible light harvesting type II semiconductor • Enhanced photocatalytic efficiency is attributed to the retarded rate of recombination of photoexcitons. • Superoxide radical is most reactive species responsible for the photodegradation. [ABSTRACT FROM AUTHOR]

Abstract Zinc Vanadate Zn 3 (VO 4) 2 nanoplates with width and thickness 300–500 nm and 50–75 nm diameter were synthesized by the facile modified hydrothermal method. Which containing mixing of Ammonia metavanadate (NH 4 VO 3) powder with zinc acetate (Zn(CH 3 COO) 2 ·2H 2 O), in the presence of CTAB and N, N-dimethyl formamide (DMF), the pH was adjusted around 5 and white precipitates were obtained. The potential of Zn 3 (VO 4) 2 photocatalyst was investigated by degrading Congo Red (CR) and Crystal Violet (CV) dyes using a UV–visible spectrophotometer. These Zinc vanadate nanoplates (ZnVO-Nps) showed enhanced dye removal (100%) due to reduced band gap 2.68eV and high surface area (84 m2/g). The Photoluminescence measurement showed the ZnVO-Nps potential for blue/green visible optical devices. These result showed that ZnVO-Nps have higher photocatalytic degradation due to the large surface area and porosity; it is proposed that the ZnVO-Nps demonstrated the high-level application for the degradation of organic pollutants under visible light irradiation. Graphical abstract Image 1 Highlights • First time Zn 3 (VO 4) 2 with nanoplates morphology reported for the degradation of dyes. • Zn 3 (VO 4) 2 nanoplates showed excellent visible light driven photocatalytic activity. • Crystal violet and Congo red dyes degraded within 60 and 150 mints, respectively. • Interface of catalyst and dye is a promising factor for photocatalytic degradation. • This method provides a simple and cost economical manufacturing process. [ABSTRACT FROM AUTHOR]

In this work, two new N-annulated perylene-based organic sensitizers ( PY-1 and PY-2 ) have been developed for dye-sensitized graphitic carbon nitride (g-C 3 N 4 ) to remarkably enhance photocatalytic hydrogen production under visible-light irradiation (420 nm ≤ λ ≤ 780 nm). The results showed that the H 2 production rates of the PY-1 /g-C 3 N 4 /Pt and PY-2 /g-C 3 N 4 /Pt were up to 5508.1 μmol h −1 g −1 and 11,855.4 μmol h −1 g −1 , respectively, which were 8.98 and 19.3 times higher than that of the g-C 3 N 4 /Pt, respectively. Specifically, an impressive record apparent quantum efficiency (AQY) of 27.16% for PY-2 /g-C 3 N 4 /Pt system was achieved at λ = 550 nm monochromatic light irradiation. Moreover, the formation of amide bonds between dye molecules and g-C 3 N 4 was firstly confirmed by FTIR spectrum and theoretical calculation. The amide bonds provided the electron transfer channels to significantly improve interface charge transfer and separation, thus resulting in a more efficient hydrogen production. More importantly, PY-1 /g-C 3 N 4 /Pt and PY-2 /g-C 3 N 4 /Pt displayed good stability under long-term irradiation and was favorable and significant for practical application. Our work indicated that dye sensitized g-C 3 N 4 to form an amide bond is a promising strategy to realize the effective conversion of solar energy to hydrogen energy through molecular engineering. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Vanadium oxide improved the photocatalytic activity of four different supports. • Brønsted acid sites concentration on V 2 O 5 /ZM5 and V 2 O 5 /TiO 2 is higher than V 2 O 5 /SBA. • Remarkable photocatalytic activity was observed on V 2 O 5 /ZM5 under visible light. • V4+ species and Brønsted acid sites improved the photocatalytic degradation of Eosin Y. • V 2 O 5 supported on TiO 2 and zeolite ZM5 are highly efficient to eliminate organic dye pollutants. Abstract SBA, zeolite-ZM5, TiO 2 and P25, used as dispersant agents of vanadium oxide, were synthesized. The supports (SBA, Zeolite-ZM5, TiO 2 and P25) were loaded with 3 wt.% of V 2 O 5. V 2 O 5 /ZM5, V 2 O 5 /P25 and V 2 O 5 /TiO 2 showed high photocatalytic activity for the degradation of Eosin Y employing a visible light source (450 nm). The photocatalysts were characterized by X-ray diffraction, XPS, UV-vis, S BET , SEM, TEM, and FTIR (surface acidity). Under visible light, the photocatalytic degradation rate displayed the following order V 2 O 5 /TiO 2 (93%) > V 2 O 5 /P25 (81%) > V 2 O 5 /ZM5 (70%) > V 2 O 5 /SBA (55%). This behavior is in conjunction attributable to the oxidation state of the vanadium species V4+ and the presence of Brønsted acid sites. The structure and properties of the TiO 2 play an important role during the photodegradation of the Eosin Y. Results here obtained give new insights for the water treatment processes using visible light over vanadium photocatalysts. [ABSTRACT FROM AUTHOR]

Abstract Photocatalysis, a green technique is widely applied in the fields of environmental remediation for the removal of many pollutant constituents. It is known that major problems related to the present photocatalytic system, which significantly limit their photocatalysis efficiency, are low-usage of visible light, fast recombination and also the low migration ability of the photo-generated electrons and holes. To solve the problem associated with conventional photocatalytic systems, recently hybrid photocatalysts containing carbon quantum dots (CQDs) have been proposed. The tunable photocatalytic characteristics of CQDs are widely mentioned. Moreover, the excellent photocatalytic activity of CQDs alone and in combination with photoactive species in the photo-degradation of organic pollutants was confirmed in the many reports. This work presents a comprehensive view of the application of CQDs to improve conventional photocatalytic systems in those studies which considered organic dyes as sample pollutants. In addition to providing detailed information regarding important roles of CQDs in photocatalytic activity enhancement, this review provides the comprehensive details about findings of the photocatalytic degradation of dyes using CQD-based photocatalysts and the best CQD-based composites photocatalysts are highlighted. Highlights • Combination of CQDs/conventional photo-catalysis systems improved their performance. • Multifunctional roles of CQD in photo-catalysis ate extensively elucidated. • CQD-based photo-catalysis degradation of organic dyes is comprehensively reviewed. [ABSTRACT FROM AUTHOR]

Cerium oxide nanoparticles, synthesized by microwave mediated hydrothermal method, was characterized by using XRD, FT-IR, SEM, TEM, XPS, DR/UV–vis, and BET analyzer and applied for simultaneous adsorption/ photocatalytic decolourisation of two commonly used organic dyes namely Alizarin red S (ARS) and Eriochrome black-T (EBT). Powder XRD pattern coupled with SEM/TEM revealed the formation of single cubic phase spherical CeO 2 nanoparticles with average particle size of ∼15 nm. The sample showed moderate specific surface area (47.73 m 2  g −1 ) and relatively lower band gap (2.78 eV) than bulk CeO 2 . XPS study confirmed the existence of both Ce 4+ and Ce 3+ in the prepared sample. Batch adsorption studies without light irradiation showed significant adsorption of both the dyes on CeO 2 nanoparticles with monolayer adsorption capacity (Q o ) values 44.1 and 57.8 mg g −1 for ARS and EBT, respectively. Under visible light irradiation, the overall decolourisation (adsorption/photo-degradation) of both the dyes increased substantially and the optimum amount of CeO 2 required for complete decolourisation of ARS (100 mg L −1 ) was 0.80 g L −1 while relatively lesser dose of catalyst (0.60 g L −1 ) was required for the same concentration of EBT. Suitable mechanisms were proposed for the decolourisation of dyes under visible light based on GC–MS/LC–MS data of the degraded products/intermediates. [ABSTRACT FROM AUTHOR]

Solvothermal reaction in tren/tatda mixed polyamines produced a transition metal (TM) thiostannate [Mn(tren)(H 2 O)][Mn(baen)] 3 Mn 4 Sn 6 S 20 ∙9H 2 O ( 1 ) containing a novel T3 supertetrahedral nanocluster [Mn 4 Sn 6 S 20 ] 8− . The T3 cluster was constructed by SnS 4 and MnS 4 tetrahedra via corner-sharing with the SnS 4 tetrahedra occupying four corners of the T3 cluster. It has different TM/Sn ratio from the traditional T3 cluster [TM 5 Sn 5 S 20 ] 10− (TM = Zn, Co) prepared by extraction method using alkali cations as the counter ions. Compound 1 is the first T3 cluster of the TM-Sn-Q phase prepared by solvothermal method and stabilized by TM-amino complex counter ions. The same solvothermal reaction with Se instead of S afforded a selenidostannate [Mn(baen)] 2 Sn 2 Se 6 ( 2 ) containing a dimeric [Sn 2 Se 6 ] 4− anion. Compound 1 exhibits selective photocatalysis in photodegradation of organic dyes. It has higher photocatalytic effect in the photodegradation of crystal violet (CV) than rhodamine B (RhB) under visible light irradiation at room temperature. [ABSTRACT FROM AUTHOR]

The photocatalytic activity of ZnO:Mo/GCN (ZnO:Molybdenum/g-C 3 N 4 ) thin films deposited using a simple cost-effective jet nebulizer spray pyrolysis technique with different Mo doping concentrations (1,2 and 3 at.%) was studied. The photocatalytic degradation test was carried out against Methylene blue (MB) and Rhodamine B (RhB) dyes under visible light. It is found that thin film of ZnO:Mo/GCN with 1 at.% of Mo exhibits superior photocatalytic efficiency compared with the other samples. The degradation rate constant of this sample is 0.0727 and 0.0268 min −1 for the tested MB and RhB dyes, respectively which are nearly two times and four times greater than the respective rate constant values of pristine ZnO. The mechanism involved in the enhanced photocatalytic activity is addressed with the help of obtained results. The properties of the deposited samples are correlated appropriately with the photocatalytic efficiency of the samples. The photostability of the prepared catalysts is tested experimentally. [ABSTRACT FROM AUTHOR]

Synthesis and characterization of the pristine NiO, Bi 2 O 3 and composite NiO–Bi 2 O 3 (NBO) nano material systems with the modified surface morphology is reported. The NBO and pure oxide materials are thoroughly characterized with various spectroscopic methods such as XPS, p-XRD, FTIR, Raman, UV–vis-DRS, PL, FESEM and HRTEM analysis. XRD results showed the formation of a new γ-phase of Bi 2 O 3 after incorporating Ni on its surface. XPS and EDX analysis confirmed the presence of both Ni2+ and Bi3+ in the nanoparticles. HRTEM analysis showed NiO nanospheres on Bi 2 O 3 nanorods with 13–18 nm nanoparticle sizes Furthermore, as a result of composite phase formation, a substantial decrease in bandgap from 3.28 to 2.62 eV is found, which was captivating to study the visible light energy induced photodegradation of methylene blue (MB), methyl orange (MO) dyes and agricultural soil pollutants (ASP). The effect of pH, dosage, and scavenger's studies are investigated to establish the mechanism of the active species of the photodegradation process and which is supported by photocurrent and EIS studies. Under the optimal framework, the photocatalytic degradation efficacy of the MB, MO dyes and ASP degradation with NBO was 95, 90 and 94% respectively. Additionally, HPLC analysis of initial and final samples of dyes was studied and TOC analysis for ASP examined. NBO catalyst was recovered and reused umpteen times with marginal change in photocatalytic efficiency. NBO nano composite material act as photocatalyst for photodegradation of MB and MO dyes and agricultural soil pollutants under visible light treatment because of electron-hole pair recombination is low. [Display omitted] • Preparation of pure NiO, Bi 2 O 3 and new NiO–Bi 2 O 3 composite nanomaterials by wet-impregnation method and thoroughly characterized. • Photodegradation of organic dye pollutants such as methylene blue, methyl orange under visible light irradiation. • Photodegradation of agricultural soil pollutants was investigated and identified with LC-MS data. • Mechanistic studies established that the active species are hydroxy radials via several foragers studies. [ABSTRACT FROM AUTHOR]