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In this study, Ag-AgCl/attapulgite (Ag-AgCl/ATP) composites were synthesized via a direct precipitation method using ATP nanorods as a catalyst supporter. ATP nanorods helped to increase the dispersion of Ag-AgCl particles and broaden the light absorption spectrum, which would also help to increase the active site of the catalyst to promote the degradation of tetracycline (TC). The photocatalytic activity of the Ag-AgCl/ATP composites was evaluated through the degradation of TC, identifying the loading amount of Ag-AgCl, the concentration of TC, and the reaction temperature as critical factors influencing activity. Specifically, the optimal conditions were observed when the loading of Ag-AgCl was 75%, resulting in a photocatalytic degradation efficiency of 77.65%. Furthermore, the highest degradation efficiency (85.01%) was achieved with a TC concentration of 20 mg/L at 20 °C. Radical trapping experiments suggested that the superoxide anion radical (·O2−) was the primary active species in the degradation process, although hydroxyl radicals (·OH) and holes (h+) also contributed. Reusability tests confirmed that the Ag-AgCl/ATP composites exhibited excellent stability and could be effectively reused. [ABSTRACT FROM AUTHOR]

Introduction. Currently one of the focus areas for the development of construction material science is the creation of self-cleaning concretes characterized by polydisperse multicomponent composition with the presence of nanoscale photocatalytic additives, primarily based on TiO2 . These photoactive modifiers give the material a number of positive properties, including the ability to decompose atmospheric pollutants, to self-clean the surface, etc. The promising method for improving the functional characteristics of titanium oxide photocatalysts is the creation of nanostructured systems with ‘core (substrate) – shell (photocatalyst)’ architecture. Previous research results show that the final efficiency of the synthesized composite photocatalytic modifiers largely depends on the level of substrate reactivity in the cement system. The purpose of this study is to investigate the impact of three types of siliceous rocks (diatomite, trepel, and opoka) on cement stone formation processes and to identify the most effective raw materials for use as photocatalytic carriers in self-cleaning concrete compositions. Methods and materials. The methods of Kozeny-Karman, laser diffraction and X-ray fluorescence spectrometry were used to determine the specific surface area and parameters of granulometric and chemical compositions of silicite samples. The phase composition of siliceous rocks and modified cement systems was studied by X-ray powder diffractometry. Results and discussion. The main parameters of granulometric composition of diatomite, trepel and opoka were determined. The predominance of reactive modifications of free silica (47.6–78.0 wt. %), represented by amorphous opal-A or cryptocrystalline OCT-phase (opal-CT), were revealed in the structure of silicites. It was found that increasing the dosages of silica-containing additives from 0 to 10% resulted in decreased by 10–27% in the quantity of portlandite in the phase composition of cement stone aged 28 days, while the content of high-strength low-basic calcium hydrosilicates (C–S–H (I)) increased by 11–27%. Conclusion. The chemical and mineralogical composition peculiarities of silicites, as well as the nature of the impact of silica-containing modifiers on the structure formation processes of cement systems, determine the prospects of using opal-cristobalite rocks as dispersed photocatalyst carriers for self-cleaning concrete.

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In this study, we developed a novel p-n/Z-scheme heterojunction photocatalyst, ZnCo2O4/BiOBr (ZCo/BB), through a straightforward and safe hydrothermal-calcination-solvent thermal method. The composite photocatalyst demonstrated exceptional photocatalytic efficacy, particularly when the mass ratio of ZnCo2O4 was 25% (referred to as 25% ZCo/BB). Structural characterization and electrochemical analysis revealed that 25% ZCo/BB exhibited a larger specific surface area and a faster electron transfer rate. Under visible light exposure for 30 min, methylene blue (MB) degradation reached 92%, and the reaction rate constants were 8.2 and 3.7 times higher than those observed for individual ZnCo2O4 and BiOBr, respectively. Furthermore, the 25% ZCo/BB demonstrated exceptional photocatalytic stability over four cycles, maintaining over 80% MB degradation after each cycle. The outstanding photocatalytic activity was attributed to the p-n/Z-scheme heterojunction construction, which promoted charge separation and inhibited carrier recombination. In addition, ·OH and h+ were the major active species in photocatalysis, and · O 2 - was identified as a secondary active species. This work presents an efficient heterojunction photocatalyst for the degradation of organic wastewater. [ABSTRACT FROM AUTHOR]

Heterogeneous photocatalysis is a promising technique for removing pollutants from water. In this work, supercritical antisolvent (SAS)-micronized ZnO (ZnOSAS) is coupled with commercial anatase TiO2 (PC50) to study the photocatalytic degradation of ceftriaxone under UV and visible light. Diffuse ultraviolet–visible reflectance (UV−vis DRS) measurement revealed that the presence of ZnO leads to a slight absorption in the visible region. Wide-angle X-ray diffraction (WAXD) analysis showed the presence of both ZnO wurtzite and TiO2 anatase crystalline phases in the composite. Photocatalytic tests proved that the activity of the ZnOSAS/PC50 composite is higher than that of commercial ZnO, SAS-micronized ZnO, and PC50, allowing complete ceftriaxone degradation under UV light after only 2 min of irradiation time. In contrast, about 90% of ceftriaxone degradation is achieved after 180 min of visible-light irradiation. The photocatalytic results for an experiment carried out in the presence of probe scavenger molecules for reactive oxygen species show that hydroxyl radicals and positive holes are both reactive species involved in the ceftriaxone photocatalytic degradation mechanism. Finally, reuse cycles of the ZnOsas/PC50 composite are performed, demonstrating the stability and recyclability of the photocatalyst. [ABSTRACT FROM AUTHOR]

The industrially feasible TiO2-clay based photocatalysts are essential to overcome the practical barriers that are intrinsic to currently available clay-based photocatalysts. The present study demonstrates the fabrication of heterogeneous photocatalyst consisting of TiO2 and kaolinite (TKCP) that has shown improved catalytic activity and strength, ensuring industrial viable photocatalyst. TKCP is prepared via an economical method, employing mechanical compression and dehydroxylation, forming TiO2-clay hybrid matrix. Amount of clay primarily determines mechanical strength and photocatalytic efficiency of TKCP where TKCP with the lowest clay percentage results in a homogeneous matrix that consists of tiny TiO2 particles embedded clay sheet-like structure. The TiO2 particles embedded clay sheet-like structure is responsible for the high specific surface area and small pore size, increasing the active surface that is available for effective disintegration of organic contaminants. By increasing clay fraction in TKCP, a significant increase in surface defects can be observed due to large clay fragments and TiO2 agglomerates, which results in flexural strength and catalytic activity decrease. Methylene blue degradation on TKCP with the maximum TiO2 percentage results in the highest pseudo first-order rate constant of 0.58 h−1, exhibiting improved photocatalytic activity due to well-organized matrix and high specific surface area (82.79 m2 g−1). TKCP can be obtained in variable sizes and shapes that ensure dynamic wastewater treatment applications.

In this study, Ag-AgCl/attapulgite (Ag-AgCl/ATP) composites were synthesized via a direct precipitation method using ATP nanorods as a catalyst supporter. ATP nanorods helped to increase the dispersion of Ag-AgCl particles and broaden the light absorption spectrum, which would also help to increase the active site of the catalyst to promote the degradation of tetracycline (TC). The photocatalytic activity of the Ag-AgCl/ATP composites was evaluated through the degradation of TC, identifying the loading amount of Ag-AgCl, the concentration of TC, and the reaction temperature as critical factors influencing activity. Specifically, the optimal conditions were observed when the loading of Ag-AgCl was 75%, resulting in a photocatalytic degradation efficiency of 77.65%. Furthermore, the highest degradation efficiency (85.01%) was achieved with a TC concentration of 20 mg/L at 20 °C. Radical trapping experiments suggested that the superoxide anion radical (·O2−) was the primary active species in the degradation process, although hydroxyl radicals (·OH) and holes (h+) also contributed. Reusability tests confirmed that the Ag-AgCl/ATP composites exhibited excellent stability and could be effectively reused.

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BACKGROUND: According to the characteristics of various nanomaterials, assembling these nanomaterials is an effective way to control the structure and properties of nanocomposites. RESULTS: In this work, nanofiltration membranes (NM) were prepared by assembling several nanomaterials that have excellent separation and catalytic properties. SiO2 nanoparticles were employed to optimize the water nanochannels between graphene oxide (GO) nanosheets to fabricate GO/SiO2 NM, whose water flux was 73.2 L m−2 h−1 and the rejection ratio was 99.1%. The combination of high‐conductivity hydroxylated graphene (G‐OH) with flake NiCo‐BDC (BDC refers to deprotonated terephthalic acid) ultra‐thin metal organic framework (UMOF) to obtain UMOF&G‐OH could improve the catalytic performance of the UMOF by about 23.5%. In order to realize the synchronous catalysis and separation performance of nanofiltration membrane, UMOF&G‐OH was reassembled with GO and SiO2. The pure water flux of (UMOF&G‐OH)/GO/SiO2 nanofiltration membrane was 95.8 L m−2 h−1 and the rejection ratio was 99.1%. TiO2 nanoparticles were added to the membrane to regulate the distance between the flake, and the selective permeation of the composite membrane was further improved to 99.9%; the pure water flux reached 92.6 L m−2 h−1. CONCLUSION: The introduction of G‐OH would be beneficial in improving the migration and separation efficiency of the photogenerated electron holes, and effectively improve the catalytic performance of the semiconductor catalyst. Through the assembly of a variety of nanoparticles and lamellar materials, the water nanochannel could be accurately controlled and the catalytic performance of the membrane could be given, so as to obtain a nanofiltration membrane with high water flux and high rejection ratio. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

With the improvement of economic level and the development of science and technology, the problem of water pollution needs to be solved now. Various water pollutants have a negative impact on nature and restrict its development. In recent years, photocatalysis is considered to be a promising wastewater treatment method. Two-dimensional carbon materials have become the hotspot of photocatalytic degradation of pollutants because of their excellent conductivity, large specific surface area, and good hydrophilicity. Nevertheless, it is very hard for these photocatalysts based on carbon materials to separate and recover from the system. For solving such a problem, the composition with magnetic components is an effective way which can facilitate separation and keep the catalytic activity of the samples. In this review, the main roles of magnetic carbon-based composites in the field of pollutant degradation are introduced, and their synthesis technology, classification, and application are summarized. In the end, the current challenges and prospects in this field are involved, aiming to provide useful insights and enlightments into the fields of pollutant treatment and photocatalytic degradation. [ABSTRACT FROM AUTHOR]

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The goal of this paper is to improve the technical level of preparing composite photocatalysts with SiO2-supported nano-TiO2, expand the selection range of SiO2 carriers, reduce expenses and understand the influence of SiO2 crystallization behavior. Natural quartz (Q/SiO2) powder was used as a carrier to prepare a Q/SiO2-TiO2 composite photocatalyst by hydrolyzing a butyl titanate solution and performing high-temperature calcination of the hydrolysate. The performance, morphology, structure and mechanism were tested and characterized. In addition, the as-prepared photocatalyst was compared with other amorphous SiO2 carrier composite photocatalysts. The results showed that the Q/SiO2 surface of Q/SiO2-TiO2 contained a uniform load of TiO2 with a 26.98% proportion. Anatase-type TiO2 was mainly present, and the size was 5–10 nm. Moreover, Q/SiO2 and TiO2 were firmly combined in the form of Si–O–Ti bonds between the interfaces. The degradation rate of Q/SiO2-TiO2 to methyl orange solution was 99.59% under UV irradiation for 60 min, which was equivalent to that of pure nano-TiO2. The degradation performance remained stable after four cycles. Compared with other amorphous SiO2 carriers, Q/SiO2 exhibited a higher load of TiO2. Furthermore, Q/SiO2 played a more significant role in inhibiting the phase transition of TiO2 to rutile and improving the photocatalytic performance. [ABSTRACT FROM AUTHOR]

The ZnS/Cd 1-x Zn x S composite photocatalyst was successfully synthesized using a hydrothermal solvent by adding excess hydroxide ions. The ZnS/Cd 1-x Zn x S composite photocatalyst showed excellent photocatalytic activity for hydrogen production with a hydrogen evolution rate of 21.8 mmol/g−1 h−1, which is the highest photocatalytic activity reported to date among visible-light-driven photocatalysts without loading cocatalysts. According to the theoretical calculation and analysis of the chemical equilibrium in the synthesis process, the synthesized Cd 1-x Zn x S solid solution contained a certain amount of ZnS. A certain amount of ZnS was also contained in the synthesized Cd 1-x Zn x S solid solution based on experimental results, thus demonstrating the validity of the theoretical calculation. Experimental results showed that the key factor affecting the photocatalytic activity of hydrogen production for the ZnS/Cd 1-x Zn x S composite photocatalyst was not the heterojunction formed between ZnS and Cd 1-x Zn x S but rather the stacking fault structures in the Cd 1-x Zn x S solid solution. However, more stacking fault structures could be formed in the Cd 1-x Zn x S solid solution due to the presence of ZnS. • The effect of chemical equilibrium theory to the performance of hydrogen production for catalysts was clarified. • Thus theory inferred the existence of ZnS in the Cd 1-x Zn x S and then the experiments proved the theory. • The presence of ZnS formed more stacking fault structures in the Cd 1-x Zn x S. [ABSTRACT FROM AUTHOR]

In this study, composite materials based on nanocrystalline anatase TiO2 doped with nitrogen and bismuth tungstate are synthesized using a hydrothermal method. All samples are tested in the oxidation of volatile organic compounds under visible light to find the correlations between their physicochemical characteristics and photocatalytic activity. The kinetic aspects are studied both in batch and continuous-flow reactors, using ethanol and benzene as test compounds. The Bi2WO6/TiO2-N heterostructure enhanced with Fe species efficiently utilizes visible light in the blue region and exhibits much higher activity in the degradation of ethanol vapor than pristine TiO2-N. However, an increased activity of Fe/Bi2WO6/TiO2-N can have an adverse effect in the degradation of benzene vapor. A temporary deactivation of the photocatalyst can occur at a high concentration of benzene due to the fast accumulation of non-volatile intermediates on its surface. The formed intermediates suppress the adsorption of the initial benzene and substantially increase the time required for its complete removal from the gas phase. An increase in temperature up to 140 °C makes it possible to increase the rate of the overall oxidation process, and the use of the Fe/Bi2WO6/TiO2-N composite improves the selectivity of oxidation compared to pristine TiO2-N. [ABSTRACT FROM AUTHOR]

The ever‐increasing quantity of spent lithium‐ion batteries (LIBs) is both a potential environmental pollutant and a valuable resource. The spent LIBs recycling mainly aimed at the separation of valuable elements. Some issues still exist in these processes such as high energy consumption and complex separation procedures. This study avoided element separation and proposed a facile approach to transform spent LiCoO2 electrode into a lithium (Li)‐doped graphitic carbon nitride (g‐C3N4)/Co3O4 composite photocatalyst through one‐pot in situ thermal reduction. During the thermal process, melamine served as the reductant for LiCoO2 decomposition and the raw material for g‐C3N4 production. Li was in situ doped in g‐C3N4 and the generated Co3O4 was in situ integrated, forming a Li‐doped g‐C3N4/Co3O4 composite photocatalyst. This special composite exhibited an enhanced photocatalytic performance, and its photocatalytic H2 production and RhB degradation rates were 8.7 and 6.8 times higher than those of g‐C3N4. The experiments combined with DFT calculation revealed that such enhanced photocatalytic efficiency was ascribed to the synergy effect of Li doping and Co3O4 integrating, which extended the visible light absorption (450–900 nm) and facilitated the charge transfer and separation. This study transforms waste into a high‐efficient catalyst, realizing high‐valued utilization of waste and environmental protection. [ABSTRACT FROM AUTHOR]

Heterogeneous photocatalysis is a promising technique for removing pollutants from water. In this work, supercritical antisolvent (SAS)-micronized ZnO (ZnOSAS) is coupled with commercial anatase TiO2 (PC50) to study the photocatalytic degradation of ceftriaxone under UV and visible light. Diffuse ultraviolet–visible reflectance (UV−vis DRS) measurement revealed that the presence of ZnO leads to a slight absorption in the visible region. Wide-angle X-ray diffraction (WAXD) analysis showed the presence of both ZnO wurtzite and TiO2 anatase crystalline phases in the composite. Photocatalytic tests proved that the activity of the ZnOSAS/PC50 composite is higher than that of commercial ZnO, SAS-micronized ZnO, and PC50, allowing complete ceftriaxone degradation under UV light after only 2 min of irradiation time. In contrast, about 90% of ceftriaxone degradation is achieved after 180 min of visible-light irradiation. The photocatalytic results for an experiment carried out in the presence of probe scavenger molecules for reactive oxygen species show that hydroxyl radicals and positive holes are both reactive species involved in the ceftriaxone photocatalytic degradation mechanism. Finally, reuse cycles of the ZnOsas/PC50 composite are performed, demonstrating the stability and recyclability of the photocatalyst.

Conjugated polymers such as polyaniline (PANI), polypyrrole, and polythiophene have attracted much attention owing to their good electrical conductivity, stability, ease of preparation, and high application potential. Among these conjugated polymers, PANI has attracted much attention in the field of photocatalysis owing to its ability to absorb visible light and rapidly separate the photoexcited electron–hole pairs. Recently, a large number of studies have shown that PANI can substantially increase the photocatalytic activity under both UV light and natural sunlight irradiation. Considering this most unique performance of PANI-based photocatalysis, the applications of PANI in the preparation of composite photocatalysts for the photocatalytic degradation of dyes, pharmaceuticals, and pesticides are summarized. In this review, the preparation methods, morphology, and photocatalytic properties of various composites are systematically studied. Synergistic effects between PANI and semiconductor nanomaterials or other carbon materials were found in many composite photocatalysts. Moreover, the mechanism of photocatalytic activity enhancement can be explained by analyzing the band structure of composite photocatalyst. [ABSTRACT FROM AUTHOR]

TiO2 is the most studied photocatalyst because of its non-toxicity, chemical stability, and low cost. However, the problem of TiO2 is its low activity in the visible region of the spectrum. In this study, we focused on the preparation of composite photocatalytic materials with altered light absorption properties. TiO2 P25 and various metal oxides were mechanically joined by ball-milling and immobilized on glass plates. The prepared samples were evaluated based on their ability to degrade NO in gas phase. The formation of undesirable byproducts was also investigated. Four best performing composites were later chosen, characterized, and further evaluated under various conditions. According to their performance, the metal oxide additives can be divided into three groups. P25/Fe2O3 showed the most promising results—an increase in overall deNOx activity under modified ISO conditions and altered selectivity (less NO2 is formed) under both simulated outdoor and simulated indoor conditions. On the other hand, P25/V2O5 composite showed negligible photocatalytic activity. The intermediate group includes P25/WO3 and P25/ZnO photocatalysts, whose performances are similar to those of pristine P25. [ABSTRACT FROM AUTHOR]

The SMOCN composite photocatalyst prepared by ultrasonic assisted hydrothermal approach with a feasible direct Z-scheme mechanism, which could be effectively degrade Cip under visible light. [Display omitted] • SrMoO 4 /g-C 3 N 4 composite photocatalyst with the morphology of 0D SrMoO 4 nanoparticle and 2D g-C 3 N 4 nanolayer was prepared by ultrasonic assisted hydrothermal approach. • Excellent photocatalytic activity and reliable stability of SrMoO 4 /g-C 3 N 4 in ciprofloxacin photodegradation was verified. • The optical complementary properties and catalytic synergies between SrMoO 4 and g-C 3 N 4 was elucidated. • The possible Type-ii and direct Z-scheme mechanisms of SrMoO 4 /g-C 3 N 4 composite were compared, and the rationality of SrMoO 4 /g-C 3 N 4 heterojunction following the direct Z-scheme charges migration mechanism was verified. Ciprofloxacin (Cip) is a common pollutant that causes sewage problems, and its effective removal is a great contribution to the clean water environment. Direct Zener-scheme (Z-scheme) heterojunction photocatalyst is a promising design idea for the removal of residual antibiotics in water. The goal of this study is to construct a binary composite photocatalyst with Z-scheme heterojunction to effectively remove residual ciprofloxacin in wastewater. Herein, a direct Z-scheme 0D/2D SrMoO 4 /g-C 3 N 4 (SMOCN) composite photocatalyst was synthesized by ultrasonic-assisted hydrothermal way and its interior information (chemical structure, micromorphology, and physic-optical property) was detected by various characterization instruments (XRD, FT-IR, EDX, XPS, UV–Vis DRS, and PL). Meanwhile, the photocatalytic activity of all-prepared catalysts were estimated by Cip photodegradation experiments under simulated sunlight (500 W Xenon lamp). Among them, 89.9 % of Cip was broken down by 30SMOCN composite within 180 min at pH 7.0, which respectively reached 2.56 times of bare SMO and 2.03 times of bare CN. Furthermore, 85.2 % of Cip targeted molecule is still removed by SMOCN (excellent stability and recyclability) after five cycle runs. Finally, the reasonableness of SMOCN conforming to the direct Z-scheme mechanism is verified by comparison of optical properties, quenching experiment results and photogenerated carrier migration paths: 1) There is optical complementarity between SMO and CN, which is represented by redshifted absorption edge, narrowed band gap and weaken PL intensity. 2) The key active site on the SMOCN composite surface is photogenerated carriers in Cip photocatalytic degradation, which given full play to the direct synergistic catalytic effect between SMO and CN heterojunction. 3) The direct Z-scheme mechanism preserves the carriers of SMOCN with effective photo-redox function, promotes their separation and prolongs their lifetime. [ABSTRACT FROM AUTHOR]

SrFe 12 O 19 as a novel magnetic matrix has drawn increasing attention in photocatalysis. In the current study, a novel magnetically recoverable In-MoO 3 /SrFe 12 O 19 ternary composite photocatalyst was fabricated with the hydrothermal method, and the photocatalytic activity was evaluated by degrading rhodamine B (RhB) solution through simulated solar irradiation. The results demonstrated that the outstanding degradation rate of RhB (96.5 %) could be achieved within 70 min when the mass ratio of both doped In and SrFe 12 O 19 in the ternary composite photocatalyst was 5 % (5-IMS-5). The enhancement of the photocatalytic degradation performance was mainly related to the self-sensitization of RhB, the magnetic field effect of SrFe 12 O 19 , and the introduction of impurity energy levels by In doping. More importantly, the degradation rate of RhB by 5-IMS-5 was still up to 90.8 % after 4 times of recycling, verifying that the prepared ternary composite sample has good recyclability and stability. This study proves a novel ternary composite photocatalyst that can be used for organic wastewater treatment, and its photocatalytic degradation mechanism provides great reference significance for the synthesis of other SrFe 12 O 19 -based magnetic semiconductor photocatalysts. • Novel magnetic photocatalyst In-MoO 3 /SrFe 12 O 19 has been successfully prepared. • The photocatalytic effect of In-MoO 3 /SrFe 12 O 19 was superior to that of single. • The possible photodegradation mechanism for RhB was proposed. • Excellent recyclability and stability of In-MoO 3 /SrFe 12 O 19. [ABSTRACT FROM AUTHOR]

Photocatalysis is one of the most preferred methods for the degradation of organic pollutants as it can lead to complete mineralization of organic pollutants employing sunlight as an energy source. Until so far enormous number of investigations have been done regarding the development of visible light responsive, stable, and cost effective photocatalysts. In the present work, owing to objectives mentioned above, an attempt was made to develop an efficient, cheaper, and visible light active composite photocatalyst consisting of moderate band gap, CuWO4 with electron conductive graphene quantum dots. A series of photocatalysts was prepared by varying the amount of CuWO4 while keeping the amount of GQDs fixed, and their activity was evaluated for the phenol degradation under visible light irradiation. The prepared photocatalysts were characterized by using X-ray diffraction (XRD), Scanning electron microscopy (SEM), Raman spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, and Photoluminescence (PL) for the evaluation of crystallinity, functional groups, and properties of charge carrier separation, respectively. The maximum efficiency of photodegradation of phenol simulated wastewater was achieved by sample 0.5GCW (optimized sample having 0.5 wt% of CuWO4 with respect to fixed amount of GQDs), 53.41%, as compared to the pure CuWO4 sample, which exhibited 19.08% efficiency. A possible mechanism for enhanced activity of CuWO4 is proposed mainly due to efficient transfer of electrons from CuWO4 to graphene quantum dots. The results show that the graphene quantum dots GQDs with the CuWO4 significantly contributes to the improvement of photocatalytic performance.

Graphite carbon nitride (g-C3N4) is a promising photocatalyst for its high catalytic activity, low-cost and high-biosafety characteristics. Due to the complexity of underwater photochemical reaction conditions and the disadvantages of g-C3N4 itself such as low specific surface area, easy recombination of photogenerated electron–hole pairs and insufficient light absorption capacity, the application of g-C3N4 in the field of water purification is limited. For improving underwater photocatalytic performance of g-C3N4, a g-C3N4/carbon nanotubes (CNT-CN) composite photocatalyst with high specific surface area and enhanced light absorption capacity were prepared by in situ solvothermal method. Its photodegradation efficiency at different underwater transmission light was further studied. The results show that CNT has good compatibility with g-C3N4. g-C3N4 can grow in situ on the surface of CNT and form a stable composite structure. Moreover, its degradation efficiency under long-wavelength irradiation is improved significantly. The degradation rate of CNT-CN at 550-700 nm was about 3 times than that of g-C3N4. Furthermore, CNT-CN can maintain higher photocatalytic activity under water. At 40 cm depth where light intensity and ultraviolet spectra were attenuated 63.8% and 80.1%, respectively, the degradation rate of CNT-CN3 can still reach 3.49 times than that of g-C3N4. Based on this study, the introduction of CNT effectively promotes the electron–hole separation efficiency of g-C3N4, widens its spectral response range, and thus improves its underwater degradation efficiency. [ABSTRACT FROM AUTHOR]

Excessive discharge of toxic dyes is detrimental to ecological system and human health. Therefore, an effective photocatalyst must be designed and developed to degrade dyes from wastewater. Herein, a novel one-dimensional (1D) flower-like recoverable ZnFe2O4/C/MnO2/BiOI magnetic composite photocatalyst was synthesized via electrospinning technique combined with hydrothermal method. The photocatalytic activities of composite photocatalyst were evaluated by degrading methyl orange (MO) and Rhodamine B (RhB) under simulated light irradiation. The efficiency of ZnFe2O4/C/MnO2/BiOI photocatalyst in visible light for 150 min reached 91% (MO) and 120 min reached 94% (RhB). Moreover, the degradation rate of MO still remained 78% after five cycles. The design of 1D magnetic flower-like composite provided a new strategy for preparing photocatalysts possessing excellent photocatalytic efficiency and cyclic stability. [ABSTRACT FROM AUTHOR]

This study explores the synthesis of two visible light active organic chromophore-based composites using naphthalene monoanhydride ( Np ) and 1,7-dibromoperylene monoanhydride diester ( PMDE ). These chromophores feature favorable optical and electronic properties and polyaromatic skeletons with anhydride functionalities that facilitate π-π interactions between the chromophore and polymeric carbon nitride ( CN ) or covalent connections of chromophores with NH 2 groups of CN . Accordingly, heterogeneous chromophore- CN composite photocatalysts namely, Np/ CN (c) and PMDE/ CN (c) were prepared by adopting in situ calcination (c) and composites Np/ CN (a) and PMDE/ CN (a) were prepared by ex situ physical adsorption (a) methods. In situ prepared Np/ CN (c) and PMDE/ CN (c) composites exhibited H 2 evolution rates (HER) of 1069 and 705 μmol h -1 g -1 , respectively, which are significantly higher than ex situ Np/ CN (a) and PMDE/ CN (a) composites with HER of 465 and 252 μmol h -1 g -1 , respectively. These rates are 10, 7, 4.8, and 2.5 times higher than the bulk- CN , indicating the potential of these composites for efficient photocatalytic H 2 evolution. Surface area normalized HER enhancements were 3.8, 5.3, 6.6, and 4.2 times higher for Np/ CN (c) , PMDE/ CN (c) , Np/ CN (a) , and PMDE/ CN (a) respectively compared to bulk- CN . These composite photocatalysts exhibited excellent stabilities under prolonged photoirradiation, with H 2 evolution consistently increasing with the light exposure time. Additionally, these metal-free heterogeneous composites demonstrated efficient photocatalytic activities towards oxidative amidation of aromatic aldehydes, with up to 80% product yields, establishing the prospects of combining homogeneous and heterogeneous entities in a metal-free active material in solar energy harvesting.

The low-cost composite of g-C3N4 modified by Zn-doped SnO2 nanoparticles was prepared for the first time in this work. The characterization results of XRD and SEM demonstrated that Zn was successfully doped into SnO2. The formed Sn-O-Zn bonds and interaction between the Zn-doped SnO2 sample and g-C3N4 in the composite were explored by FT-IR and XPS technologies. Photocatalytic degradation experiments showed that the as-prepared optimal composite photocatalyst displayed enhanced photocatalytic reactivity towards both dyes and antibiotics, which could degrade 85.6% of RhB and 86.8% of tetracycline within 30 and 90 min, respectively. The oxygen vacancies formed in SnO2 after Zn doping could capture the photogenerated electrons of g-C3N4, thereby promoting the separation of photogenerated electron-hole pairs, then more ·O2− and holes can be generated during the visible light-driven photocatalytic reaction, so that the composite of Zn-doped SnO2/g-C3N4 acquired higher photocatalytic activity and accelerated the degradation of target organics. Active species capturing experiments and ESR detection results also confirmed that ·O2− and holes were the main active species in the reaction process. This work developed a novel g-C3N4-based photocatalyst with no noble metal, low price, and high photocatalytic activity, which could provide a cost-effective and high-efficiency strategy for wastewater treatment. [ABSTRACT FROM AUTHOR]

Bix Oy Brz photocatalysts display great application potential in the field of organic pharmaceutical wastewater treatment, but the high recombination rate of photogenerated electron-hole pairs limits their application. In this work, Ti3 C2 with excellent electron transfer performance was selected as a cocatalyst. Firstly, Ti3 C2-Ru cocatalyst was prepared by taking full use of abundant surface Ti vacancy defects and high reduction ability of Ti3 C2, then Bi4 O5 Br2/Ti3 C2-Ru composite photocatalysts were prepared by realizing in-situ growth of Bi4 O5 Br2 on Ti3 C2-Ru surface through the ionic bonding force between Ti3 C2 surface functional groups and Bi3+. This special structure ensures the directional transfer of electrons from Bi4 O5 Br2 to Ti3 C2 and then to the reaction active site of Ru, thereby the composite catalysts exhibit higher photogenerated carrier separation rate and lower interfacial charge transfer resistance, which effectively inhibit the recombination rate of photogenerated electron-hole pairs. The photocatalytic performance of composite photocatalysts were evaluated by the sulfamethoxazole (SMX) degradation efficiency. The results reveal that the Bi4 O5 Br2/Ti3 C2-Ru composite photocatalysts exhibit excellent photocatalytic performance on SMX degradation. The optimum removal efficiency of SMX reaches 95.1% under 75 min visible-light irradiation, which increase 36.9 percentage points of pure Bi4 O5 Br2 and 25.3 percentage points of Bi4 O5 Br2/Ti3 C2, respectively. Finally, the underlying photocatalytic mechanism was elucidated based on the radical scavenging experiments and catalyst band structure. This results will provide a novel design idea for the construction of photocatalyst with pharmaceutical wastewater treatment capability. [ABSTRACT FROM AUTHOR]

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The long-standing popularity of semiconductor photocatalysis, due to its great potential in a variety of applications, has resulted in the creation of numerous semiconductor photocatalysts, and it stimulated the development of various characterization methods. In this study, Fe2O3/Bi2WO6 composite with a flower-like microsphere and hierarchical structure was synthesized with the facile hydrothermal-impregnation method without any surfactants. X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet–visible (UV–Vis) diffuse reflectance spectroscopy, and photoluminescence spectroscopy were used to characterize the structures of the samples. The specific surface area was estimated with the Brunauer-Emmett-Teller (BET) method, and pore size distribution was determined using the Barrett-Joyner-Halenda (BJH) method. The synthesized Fe2O3/Bi2WO6 composite had an average diameter of approximately 4 nm, with smaller specific surface area and larger pore diameter than those of pristine Bi2WO6. The results of XRD and SEM analyses confirmed that the composite was composed of Fe2O3 and Bi2WO6. The absorption edge of Bi2WO6 was at a wavelength of 460 nm. By contrast, the absorption edge of Fe2O3/Bi2WO6 to visible light was redshifted to 520 nm, with narrower bandgap width and stronger visible light response. It was also found that the main active substances in the degradation of microcystin-LR (MC-LR) were hydroxyl radicals (·OH) and electron holes (h+). Consequently, the results further showed that the heterojunction between Fe2O3 and Bi2WO6 can improve the charge transfer rate and effectively separate the photoinduced electrons and holes. Compared with Bi2WO6, Fe2O3/Bi2WO6 had no significant difference in the adsorption capacity of MC-LR and had more efficient photocatalytic degradation activity of MC-LR. The degradation rates of MC-LR by Fe2O3/Bi2WO6 and Bi2WO6 reached 80% and 56%, respectively. The degradation efficiency of MC-LR was affected by the initial pH value, initial Fe2O3/Bi2WO6 concentration, and initial MC-LR concentration.

Converting lignin, a key sustainable biopolymer, into valuable oxygen-containing compounds is a significant challenge. To address such a challenge, photocatalytic self-transfer hydrogenolysis strategy is employed utilizing a CdS(x%)/TiO 2 heterojunction photocatalyst, with minimal CdS loading on TiO 2. The CdS(3 %)/TiO 2 catalyst, under blue light, dehydrogenates HC α –OH groups, transferring hydrogen to C β –O bonds, cleaving β-O-4 ether bonds in lignin model compounds yielding over 95 % phenols and acetophenones. It utilizes glyceryl moieties as a hydrogen source, yielding ∼ 24 % of diverse lignin monomer derivatives from teak lignin. Improved charge separation in the CdS(3 %)/TiO 2 catalyst is revealed by electrochemical and spectral analyses and exhibits delayed charge carrier recombination. Scavenging studies confirm a type II charge transfer mechanism and support visible-light-driven lignin fragmentation. The present photocatalytic process offers a promising, cost-effective approach for converting lignin into valuable aromatic compounds, advancing renewable biomass-derived chemicals. [Display omitted] • CdS/TiO 2 type-II heterojunction facilitated efficient charge separation. • CdS(3%)/TiO 2 afforded renewable chemicals from lignin model compounds. • Additive-free hydrogenolysis was achieved under mild photocatalytic conditions. • CdS(3%)/TiO 2 showed exceptional photocatalytic stability and reusability. • High monomer yield (24%) and excellent activity were achieved with native lignin. [ABSTRACT FROM AUTHOR]

A silica-loaded g-C 3 N 4 composite photocatalyst (M-SiO 2 /g-C 3 N 4) was prepared by grinding amorphous SiO 2 microspheres (M − SiO 2) with melamine and calcining the resulting grinding products. This composite was used for photocatalytic persulfate (PMS) activation to degrade carbamazepine (CBZ). The results showed that the degradation efficiencies of CBZ by M-SiO 2 /g-C 3 N 4 -2.5 (39.16 % of g-C 3 N 4)-activated PMS were 78.92 % and 100 % after simulated sunlight irradiation for 60 and 120 min, respectively. These values were significantly greater than those of the system with pure g-C 3 N 4 (29.15 % and 42.4 %). In particular, the degradation efficiency of CBZ with M-SiO 2 /g-C 3 N 4 -2.5 decreased by only 9.47 % after 4 cycles of recycling. In the catalytic process, h+, SO 4 •− and O 2 •− were the main reactive species contributing to CBZ degradation. Compared with g-C 3 N 4 , loading g-C 3 N 4 on the surface of M − SiO 2 resulted in a decrease in g-C 3 N 4 lamellar stacking, which increased the number of active surface sites and improved the separation and migration of photogenerated carriers, improving the degradation performance. [ABSTRACT FROM AUTHOR]

Exploiting the highly efficient photocatalyst to achieve the photocatalytic degradation of emerging contaminants is one of the research highlights in the environmental field. Herein, a novel heterostructure FeVO 4 /MIL-53(Fe) (FVOM) was constructed by depositing FeVO 4 nanorods onto the spindle-like MIL-53(Fe). The synthesized heterojunction was characterized by various methods. The photocatalytic properties of FVOM were assessed by the photodegradation of tetracycline with xenon lamp as the light source. The FeVO 4 /MIL-53(Fe) presents exceptional stability and activity. The optimum composites 10 % FVOM show the best photocatalytic activity, realizing 80.5 % of the photodegradation efficiency of TC. The photodegradation rate constant of TC by 10 % FVOM is 0.0103 min−1, which is 3 and 26 folds that by FeVO 4 and MIL-53(Fe), individually. The boosted activity may be attributed to the outstanding visible-light absorption ability of FVOM and the significantly boosted migration and separation of the photo-excited electron-hole pairs resulting from the creation of the heterostructure. Additionally, the activity of 10 % FVOM decreases by only 4.1 % after 4 cycles of reuse, exhibiting excellent stability. The Type-II interfacial charge migration mode of FeVO 4 /MIL-53(Fe) was confirmed in the light of the band structure and the reactive species. The superoxide radical is the predominant active species for the degradation of tetracycline. • A novel heterojunction photocatalyst FeVO 4 /MIL-53(Fe) was reported. • FeVO 4 /MIL-53(Fe) shows superior visible-light response and greatly effective electron transfer. • FeVO 4 /MIL-53(Fe) has excellent photocatalytic activity for the degradation of tetracycline. • The charge transfer way and photocatalytic mechanism in FeVO 4 /MIL-53(Fe) was discussed. [ABSTRACT FROM AUTHOR]

Coupling Ag NPs and direct Z-scheme heterojunction in Fe 3 O 4 @SiO 2 @ZnO-PDA-Ag photocatalysts (FSZ-PDA-Ag) were constructed via the self-polymerization of dopamine. The effects of the loading amounts of Ag NPs on the structure, morphologies, and properties of the photocatalysts were investigated. Under ultraviolet and visible light irradiation, FSZ-PDA-Ag5 exhibited superior photocatalytic activity for tetracycline degradation. Direct Z-scheme ZnO-PDA heterojunction formed in FSZ-PDA-Ag could promote the transfer efficiency of electrons, and then inhibit the recombination of photo-generated charges. Meanwhile, the appropriate load of Ag NPs acted as another conductive channel to further facilitate the electrons transfer, which could extend the lifetime of the photo-generated charges. Thus, the multiple pathways of electrons transfer resulted in the enhanced photocatalytic activity, the degradation mechanism of FSZ-PDA-Ag5 was explored in detail. Moreover, this photocatalyst possessed superior cycling stability and reusability for the wastewater purification. This study may provide a reference for designing efficient and stable photocatalysts. A novel 3D hierarchical flower-like Fe 3 O 4 @SiO 2 @ZnO-PDA-Ag photocatalyst with direct Z-scheme heterojunction has been successfully constructed via the self-polymerization of dopamine for the first time. The multiple pathways of electrons transfer resulted in the enhanced photocatalytic activity and stability of Fe 3 O 4 @SiO 2 @ZnO-PDA-Ag under ultraviolet and visible light irradiation. [Display omitted] • Novel 3D flower-like Fe 3 O 4 @SiO 2 @ZnO-PDA-Ag photocatalysts were prepared. • Coupling Ag NPs and direct Z-scheme heterojunction facilitated the catalytic reaction. • FSZ-PDA-Ag5 displayed high efficiency, recyclability and stability. • Multiple electrons transfer pathways were proposed in FSZ-PDA-Ag. [ABSTRACT FROM AUTHOR]

• Bandgap tuning of TiO 2 by CuO nanoparticles for improved photocatalytic activity. • Photocatalytic mechanism confirmed by the major contributions of h + and e − agents. • Under UV + PMS conditions, photocatalytic efficiency reaches the highest at 90%. • Membrane antifouling ability showed an FRR of 98.8% and lower surface roughness. • Membrane hydrophilization by O 2 plasma and PAA layer showed enhanced pure water flux. One direction to mitigate membrane fouling is to create anti-fouling photocatalytic membranes. The photocatalysts' hydrophilicity reduces the interaction of the membrane with hydrophobic foulants and the photocatalysis decomposes membrane fouling. Another noteworthy point is that PMS (peroxymonosulfate) can be activated by photocatalysts to decompose foulants and membrane fouling more intensely. The CuO/TiO 2 was prepared by deposition of Cu(OH) 2 onto TiO 2 followed by heat treatments. Their catalytic performances were tested by the degradation of Acid Blue 260 by photocatalysis and PMS activation. The best CuO/TiO 2 was then coated onto PVDF membranes through a PAA binding layer. Their antifouling performance was examined through simulated foulants such as sodium alginate. The photocatalysts and membranes were characterized using FTIR, SEM-EDS, TEM, XRD, BET, UV–Vis DRS, XPS, ESR, and AFM. The CuO/TiO 2 possessed a lower bandgap, high surface area (60.7 m2/g), and low particle sizes (30–60 nm). The 25%CuO/TiO 2 possesses the highest photocatalytic degradation efficiency of 39.0% under UV irradiation; further PMS activation caused the removal efficiency to reach 90.0%. The degradation efficiency by the membrane was 100% after five cycles. The membranes indicated a decrease of 18.9% in water flux but remained very high. The membrane flux recovery ratio (FRR) was 98.8%. [Display omitted] [ABSTRACT FROM AUTHOR]

In this study, composite materials based on nanocrystalline anatase TiO2 doped with nitrogen and bismuth tungstate are synthesized using a hydrothermal method. All samples are tested in the oxidation of volatile organic compounds under visible light to find the correlations between their physicochemical characteristics and photocatalytic activity. The kinetic aspects are studied both in batch and continuous-flow reactors, using ethanol and benzene as test compounds. The Bi2WO6/TiO2-N heterostructure enhanced with Fe species efficiently utilizes visible light in the blue region and exhibits much higher activity in the degradation of ethanol vapor than pristine TiO2-N. However, an increased activity of Fe/Bi2WO6/TiO2-N can have an adverse effect in the degradation of benzene vapor. A temporary deactivation of the photocatalyst can occur at a high concentration of benzene due to the fast accumulation of non-volatile intermediates on its surface. The formed intermediates suppress the adsorption of the initial benzene and substantially increase the time required for its complete removal from the gas phase. An increase in temperature up to 140 °C makes it possible to increase the rate of the overall oxidation process, and the use of the Fe/Bi2WO6/TiO2-N composite improves the selectivity of oxidation compared to pristine TiO2-N.

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Copyright of Hydrometallurgy of China is the property of Hydrometallurgy of China Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Air pollutants cause severe problems in urban areas, specifically in terms of toxicological impacts on human health. Therefore, it is urgent to develop an effective, safe, and inexpensive technique to remove these air pollutants. In this study, the MoS2/OMC heterojunction photocatalyst was successfully synthesized by a hydrothermal process and used for improving photocatalytic oxidation performance for removing VOCs. Formaldehyde was used as a model VOC in the gas phase and was removed at room temperature under visible light irradiation. For my research, the microstructure and morphology of the photocatalyst were deeply characterized, and the results indicated that MoS2 were successfully coupled into OMC materials to prepare MoS2/OMC heterojunction photocatalysts. The trend of photocatalytic efficiency for formaldehyde decomposition was MoS2/OMC > MoS2 > OMC. Besides, the MoS2/OMC heterojunction photocatalyst showed an excellent regeneration performance after several recycles, indicating the potential of MoS2/OMC composite as a promising photocatalyst for VOC removal. These results indicated that the photocatalytic reactor containing MoS2/OMC photocatalysts was highly active and stable.

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Photocatalytic degradation of oxytetracycline hydrochloride (OTC‐HCl) in marine aquaculture wastewater and therefore the effects of factors on the effectiveness of photocatalysts are studied in this paper using Zn0.75Mn0.75Fe1.5O4/ZnFe2O4/ZnO under visible light and changing the molar ratio of Zn2+:Fe3+:Mn2+, calcination temperature of catalysts, hydrogen peroxide concentration, dose of catalysts, illumination time of photocatalytic and initial concentration of OTC‐HCl. The degradation of OTC‐HCl in marine aquaculture wastewater was optimized by orthogonal experiment. The best effect exists when the molar ratio of Zn2+:Fe3+:Mn2+ was 10:1:3, the calcination temperature of photocatalyst was 400°C, the concentration of hydrogen peroxide was 0.5 g/L, the dose of catalysts was 0.6 g/L, the illumination time was 2.5 h and the initial concentration of OTC‐HCl was 0.010 g/L. The degradation rate of OTC‐HCl can reach 80.18%. Zn0.75Mn0.75Fe1.5O4/ZnFe2O4/ZnO can effectively degrade the OTC‐HCl in marine aquaculture wastewater under visible light. [ABSTRACT FROM AUTHOR]

BixOyBrz photocatalysts exhibit great potential in the application of organic pharmaceutical wastewater treatment and air purification. However, the catalysis activity and application of photocatalyst is greatly limited by its intrinsic high recombination rate of photo-generated charge carriers. In this work, a novel Bi3O4 Br / Bi12O17 Br2 composite photocatalyst was prepared via a facile in-situ hydrolysis-calcination route and its photocatalytic performance was evaluated by the sulfamethoxazole (SMX) degradation efficiency via simulated solar light irradiation. The structure and property were analyzed by X-ray diffraction ( XRD), X-ray photoelectron spectroscopy ( XPS), scanning electron microscopy ( SEM), nitrogen adsorption and desorption, UV-Vis diffuse reflectance spectra ( UV-Vis DRS), electrochemical impedance spectroscopy (EIS), Steady photoluminescence and Mott-Schottky curves. Results reveal that Bi3O4Br/Bi12O17 Br2 composite photocatalyst display the optimum photocatalytic performance, and its removal efficiency of SMX reaches 87% under 30 min simulated solar light irradiation, which is improved approximately 30% and 24% than that of pure Bi3O4Br and pure Bi12O17Br2, respectively. Based on characterization analysis, the superior performance is attributed to higher electron-hole separation rate and lower charge transfer resistance. Finally, the underlying photocatalytic mechanism was elucidated based on the band structure and radical scavenging experiments. This findings provide novel ideas and methods of the construction of the composite photocatalysts system for strong organics pharmaceutical wastewater treatment. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Henan University of Science & Technology, Natural Science is the property of Editorial Office of Journal of Henan University of Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Formation of oxygen vacancy is emerging as one type of promising defect engineering in the preparation of inorganic functional composites. In this work, a novel composite upon the calcination of the nanosheets Bi 6 O 6 (OH) 3 (NO 3) 3 ·1.5H 2 O (BBN) and g-C 3 N 4 was prepared. A large amount of oxygen vacancies was revealed by electron spin resonance (ESR) and Raman spectroscopy. These intriguing structural characters render the as-prepared composite with excellent interfacial charge transfer and photo-stimulated response as shown by electrochemical impedance spectroscopy (EIS) and photocurrent measurement. Upon visible-light activation, such composite enables photocatalyse H 2 evolution with a rate of 181 μmol h−1 g−1 around the 4.2 times that of pure g-C 3 N 4 as a reference. Such composite catalyst exhibits excellent recycling and reusable behaviors. The formation of BBN/CN heterojunction and the existence of oxygen vacancies are the main reasons for the distinctly improvement of its photocatalytic activity, which has been verified by theoretical calculations. • A novel composite BBN and g-C 3 N 4. • A new type of heterostructure with oxygen-rich vacancies. • Exhibits excellent photocatalytic performance in H 2 evolution. [ABSTRACT FROM AUTHOR]

BiFeO3/Bi2Fe4O9 composite photocatalyst was prepared by one-step sol–gel method. The phase structure, morphology, optical properties and photocatalytic activity of Bi2Fe4O9 and BiFeO3/Bi2Fe4O9 composite photocatalyst have been systematically studied. The introduction of excessive Bi and Fe nitrate into Bi photocatalyst effectively enhanced the light absorption capacity of BiFeO3/Bi2Fe4O9 composite photocatalyst. The effects substrate nature on photocatalytic activity of BiFeO3/Bi2Fe4O9 composite photocatalyst were studied with methyl orange (MO), methyl blue (MB), rhodamine B (RhB), methyl red (MR), acid red (AR), and Congo red (CR) as the target degradation dyes. The effects of dye concentration, catalyst content and pH on photocatalytic activity of BiFeO3/Bi2Fe4O9 composite photocatalyst were systematically studied with methyl orange as the main degradation dye. Photocatalytic experiments showed that the optimal dye concentration, catalyst content, and pH value were 15 mg/L, 20 mg/L, and 5, respectively. In the whole photocatalytic reaction process, hole, and hydroxyl radical play the most important role. [ABSTRACT FROM AUTHOR]

The photocatalysis of graphtic carbon nitride (g-C3N4) material has been widely used for the photocatalytic degradation of organic pollutants. However, g-C3N4 still has some drawbacks, such as the high recombination of photo-induced electron–hole pairs and weak absorption of light irradiation. To further improve the photodegradation performance of g-C3N4, a novel composite photocatalyst (CoO/ PT-C3N4) has been prepared by using a one-pot calcination method, in which cobalt oxide (CoO) as a cocatalyst are introduced on the rectangular hollow substrate of g-C3N4 (PT-C3N4), The CoO/PT-C3N4 composite photocatalyst delivers an excellent photodegradation performance for diesel oil under a simulated sunlight. It exhibits a high degradation efficiency of 95.92% after light irradiation for 2 h, which is much higher than that of pristine PT-C3N4. Free radical capture experiments manifest that the free radical of ·O2− plays a major role for the photodegradation and main active radicals abide by the sequence: ·O2− > ·OH > h+. Moreover, the CoO/PT-C3N4 composite photocatalyst delivers an excellent cyclic stability, which only degrades 8.71% photodegradation efficiency after 10 cycles. The improvement of CoO/PT-C3N4 composite photocatalyst is ascribed to the formation of a heterojunction between CoO and PT-C3N4, which promotes the separation of photo-induced carriers. This work paves a new way for the exploration of photocatalyst for the organic pollutant degradation. [ABSTRACT FROM AUTHOR]

Water pollution caused by pharmaceutical wastewater has received increasing attention, and photocatalysis is a potential method to solve this problem. In this article, La and Cr co-doped SrTiO 3 was prepared by electrospinning method, and was mixed with g-C 3 N 4 to prepare La 0.01 Sr 0.99 Ti 0.99 Cr 0.01 O 3 /g-C 3 N 4 (STO-1/CN) composite photocatalyst. The synthesized photocatalyst was characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, and UV visible diffuse reflectance spectroscopy. The optimized STO-1/CN performs enhanced absorption of visible light, and separation and migration of carriers become more effective, which contributes to improve photocatalytic performance of STO-1/CN composites. The maximum photocatalytic activity, 0.0055 min−1 was obtained by heterojunction containing 50 wt% g-C 3 N 4 (STO-50CN) in degrading CI under visible light, which was 4 and 2 times that of pure g-C 3 N 4 and La 0.01 Sr 0.99 Ti 0.99 Cr 0.01 O 3 , respectively. The active species capture experiments indicate that the photocatalytic degradation of CI by composite photocatalysts is the result of the combined action of h+ and ·O 2 -. Based on the above conclusions, a possible mechanism of La 0.01 Sr 0.99 Ti 0.99 Cr 0.01 O 3 /g-C 3 N 4 photocatalytic degradation of CI is proposed. • The La and Cr co-doped SrTiO 3 nanoparticles were successfully synthesized via electrospinning method. • The light absorption and charge carrier separation of La 0.01 Sr 0.99 Ti 0.99 Cr 0.01 O 3 were improved by modifying g-C 3 N 4. • The composite samples exhibit high visible photocatalytic activity fort antibiotics and stability. • A photocatalytic mechanism is proposed based on the band relationship of the composites. [ABSTRACT FROM AUTHOR]

[Display omitted] • Bi 2 MoO 6 was loaded on the surface of corn stalk biochar by a simple hydrothermal method. • The BMO/BC 1% demonstrates effective BPA degradation under visible light. • Biochar enhances light absorption and separation of photogenerated carriers. • h+ and ·OH are the primary active species responsible for the BMO/BC 1% degradation of BPA. In this study, Bi 2 MoO 6 was modified using low-cost and conductive corn stalk biochar (BC) by hydrothermal method to synthesis Bi 2 MoO 6 /BC photocatalytic. Under visible light irradiation, about 93 % BPA can be removed in 75 min, with a kinetic rate constant approximately 7.9 times greater than that of pure Bi 2 MoO 6. The characterization results show that Bi 2 MoO 6 /BC possesses a significant specific surface area, potentially attenuating the agglomeration of Bi 2 MoO 6 through the presence of BC. Additionally, the photocatalytic exhibits high visible light absorption capacity and a low electron-hole recombination rate, which is the primary reason for the enhancement of its photocatalytic activity. In conclusion, this study presents a simple synthesis approach for Bi 2 MoO 6 /BC and provides a theoretical foundation for the utilization of biochar in photocatalytic water treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • The photocatalysts (A-SiO 2 /TiO 2) were prepared by a simple method. • The degradation effect of photocatalysts containing 20 wt% TiO 2 is better than TiO 2. • Non-polluting preparation process and inexpensive raw material preparation. A silica-loaded nano-TiO 2 composite (A-SiO 2 /TiO 2) was prepared by wet-grinding method, using industrial silica (A-SiO 2) as the carrier. A-SiO 2 /TiO 2 was used for photocatalytic activation of peroxymonosulfate (PMS) to degrade carbamazepine (CBZ). The A-SiO 2 /TiO 2 containing 20 wt% nano-TiO 2 resulted in the CBZ degradation efficiency of 94.83 % after 90 min simulated sunlight irradiation with the presence of PMS. The main reactive species during CBZ degradation in the system of photocatalytic PMS activation by A-SiO 2 /TiO 2 were O 2 •−, •OH and SO 4 •−. Compared to nano-TiO 2 , A-SiO 2 /TiO 2 exhibits enhanced dispersion, increased surface active sites and improved photo-generated carrier separation efficiency, which contributed to enhanced degradation performance. [ABSTRACT FROM AUTHOR]

At present, the regulation of photocatalyst properties and highly efficient degradation of emerging contaminants are still challenging tasks. Herein, a novel core-shell composite catalyst Bi 2 O 4 @FeOOH was fabricated by in situ depositing amorphous FeOOH nanoparticles on the outside surface of Bi 2 O 4. A series of characterizations were conducted for the fabricated Bi 2 O 4 @FeOOH. The photocatalytic activity of Bi 2 O 4 @FeOOH was assessed via the degradation of tetracycline (TC) under visible irradiation. The formation of the amorphous FeOOH shell improves the visible-light harvesting capability, enlarges the specific surface area, and accelerates the transfer of the photo-induced electron. The synergistic effect of these positive factors enables the prepared Bi 2 O 4 @FeOOH to exhibit a considerably reinforced activity and excellent stability for TC degradation. The degradation efficiency of TC on Bi 2 O 4 @FeOOH is up to 84.2%, which is markedly higher than that over FeOOH (20.4%) and Bi 2 O 4 (43.5%). After five reuses, the activity of Bi 2 O 4 @FeOOH shows no obvious decrease. The degradation rate constant of TC by Bi 2 O 4 @FeOOH is 0.01434 min−1, which is approximately 2.4 and 5.8 times those by Bi 2 O 4 and FeOOH. This work affords a new strategy for the design of highly efficient photocatalysts that can be applied in the photocatalytic decomposition of emerging contaminants. • A novel amorphous FeOOH shell decorated Bi2O4 was reported for the first time. • The formation of core-shell structure significantly enlarges the specific surface area. • The amorphous FeOOH greatly accelerated electron transfer in Bi2O4 @FeOOH. • Bi2O4 @FeOOH exhibits excellent photocatalytic activity and stability for TC degradation. • The possible photocatalytic mechanism of Bi2O4 @FeOOH was discussed. [ABSTRACT FROM AUTHOR]