Search

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]

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.)

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]

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]

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]

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]

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.)

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department 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.)

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]

[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]

Photocatalysts are environmentally friendly materials that can be used to degrade vehicle exhaust. CeO2–Bi2O3 loaded on white carbon and tourmaline, as the favorable absorption materials, was prepared respectively for vehicle exhaust photocatalytic purification. Brunauer-Emmett-Teller (BET) adsorption isotherm, scanning electron microscope (SEM), Fourier transform infrared (FTIR), X-ray diffraction (XRD), transmission electron microscope (TEM), and X-ray photoelectron spectroscopy (XPS) were applied to characterize the composite materials. The optimum contents of the loading materials were obtained from the comparison of purification efficiency of vehicle exhaust components after a 60-min photocatalytic reaction under visible and ultraviolet (UV) irradiation, including hydrocarbons (HC), carbon monoxide (CO), carbon dioxide (CO2), and nitrogen oxides (NOx). The results show that the proposed preparation method could improve particle dispersion and distribution uniformity, reduce particle agglomeration, and increase specific surface area. The optical response range of the CeO2–Bi2O3 with loading materials can be extended from UV light to visible light. CeO2–Bi2O3 loaded on tourmaline show excellent photocatalytic purification effect under visible light. The purification efficiency of CeO2–Bi2O3 loaded on tourmaline for HC, CO, CO2, and NOx were 30.8%, 30.6%, 35.3%, and 47.6%, respectively. Moreover, the concentrations of vehicle exhaust components decrease with time, which is well fitted by the Langmuir-Hinshelwood pseudo-first-order kinetics model, and the purification rate constant of CeO2–Bi2O3 composites under visible light is greater than that under UV light. The prepared photocatalytic materials also exhibit the excellent reusability. [ABSTRACT FROM AUTHOR]

Diesel oil spills in marine environments pose a severe threat to both aquatic and terrestrial ecosystems. Photocatalysis is an environment-friendly method for marine oil remediation; however, its practical usage is limited due to several issues. In this study, we demonstrate the enhanced efficacy of doped CuO/ZrO2 photocatalyst at degrading marine diesel in comparison to undoped ZrO2. The photocatalysts were prepared using co-precipitation method, and their physical and chemical properties were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and ultraviolet-visible spectroscopy (UV-Vis). XRD analysis showed that the photocatalytic crystallite size of ZrO2 and CuO/ZrO2 was 28.80 nm and 40.32 nm, respectively. Both catalysts exhibited stable crystalline forms. UV-Vis analysis showed that doping of ZrO2 with CuO significantly reduced its band gap from 4.61 eV to 1.18 eV, thus enhancing the utilization of visible light. The effect of catalyst dosage, doping ratio, and initial diesel concentration on the degradation rate of diesel was investigated by performing single-factor experiments. The optimization experiment results showed that 96.96% of diesel could be degraded under visible light. This study laid an experimental foundation for expanding the practical applications of photocatalytic technology. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Tiangong University is the property of Journal of Tianjin Polytechnic University 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.)

A CuO/ZnO nanocomposite for use as photocatalyst was successfully prepared by co-precipitation method. Its chemical and physical properties were evaluated by X-ray diffractometry, scanning electron microscopy, EDS, UV–vis diffuse reflectance spectroscopy and photoluminescence spectroscopy. The average particle size of CuO/ZnO composite was found to be around 80 nm. The degradation of oxytetracycline hydrochloride pollutants in marine aquaculture wastewater using ZnO and CuO/ZnO was compared. CuO/ZnO nanocomposite was found to be more efficient than ZnO. The effects of external factors on the photocatalytic efficiency of the nanocomposite were investigated under visible light. Moreover, conditions for the degradation of oxytetracycline hydrochloride using CuO/ZnO nanocomposite were optimized. Based on both, the ability and efficiency of degradation, 10:1 molar ratio of Zn2+/Cu2+ and 0.4 g L–1 nanocomposite, were found to be optimal, using which the average photocatalytic degradation rate of oxytetracycline hydrochloride reached 90%. [ABSTRACT FROM AUTHOR]

Optimizing photocatalyst structure at the atomic level is a crucial challenge in improving photocatalytic performance. Herein, a series of TiO 2 /P-doped C 3 N 4 -pinned composites have been synthesized to optimize photocatalyst structure at the atomic level. Among the nonmetals (P, C, and N) in P-doped C 3 N 4 (CN-P), TiO 2 preferentially bonds with P to form stable P-O-Ti chemical bonds that can act as efficient carrier transfer channels. Comprehensive correlations between P-O-Ti bond features, defects, carrier kinetics, and photocatalytic activity have been studied theoretically and experimentally. Photocurrent-time curves and distribution of relaxation times analysis reveals that preferentially bonded P-O-Ti improves carrier separation and transfer. The special P-O-Ti interface bonds endows composites TiO 2 /P-doped C 3 N 4 with multifunctional photocatalysis properties, i.e., hydrogen production (815 µmol g−1 h−1), and completely reducing heavy metal ions Cr (VI) (10 min) under visible light (λ > 400 nm) irradiations, which outperforms most of existing CN-P and TiO 2 composite catalysts, as well as excellent degradation performance for organic contaminants. More importantly, the composite with optimal composition shows a superior stability and repeatability in ten cycles of testing. These findings provide valuable hints in optimizing photocatalyst structure at the atomic level for enhancing carrier dynamics and improving photocatalytic performance necessary for applications under visible light. [Display omitted] • TiO 2 nanoparticles pinned in P-doped C 3 N 4 have been synthesized. • TiO 2 preferentially bonds with P to form stable P-O-Ti chemical bonds. • The P-O-Ti bonds act as transport channels for photogenerated carriers. • Composite 0.33 A-TO/CN-P exhibits excellent photocatalytic performances. [ABSTRACT FROM AUTHOR]

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department 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.)

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department 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.)

Abstract: Ag3PO4/g-C3N4 nanocomposite photocatalysts were synthesized by calcining the mixture of urea and trace amount of Ag3PO4 microcrystals at 600 °C, in which Ag3PO4 nanoparticles with size of 20-30 nm were wrapped with g-C3N4 layers. The obtained Ag3PO4/g-C3N4 composites exhibited efficient utilization of visible light and separation of photoinduced electron-hole pairs, resulting in enhanced photocatalytic activity for H2 evolution. The optimum photocatalytic H2 evolution rate under visible light without Pt co-catalyst for 0.04AP-CN composite was 89.4 µmol/h, which is 3.34 times of that of g-C3N4 (26.7 µmol/h). The H2 evolution rate for 0.04AP-CN with 3 wt% Pt co-catalyst was up to 273.6 µmol/h, which is 2.39 times of that g-C3N4 (114.4 µmol/h). The performance of Ag3PO4/g-C3N4 composite was enhanced significantly due to the synergistic effect of the interface formed between Ag3PO4 and g-C3N4.Graphical Abstract: Photocatalytic mechanism of the Ag3PO4/g-C3N4 composite [ABSTRACT FROM AUTHOR]

An efficient visible-light-harvesting (λ ≥ 420 nm) three component system heterojunction photocatalyst, CdS/BiOCl/Bi 2 O 3 was prepared by anchoring of CdS nanoparticles on the surface of BiOCl/Bi 2 O 3 composite. The effect of CdS nanoparticles on the surface of BiOCl/Bi 2 O 3 composite photocatalyst had been justified in enhancing photocatalytic activity towards the degradation of organic pollutants in gas as well as aqueous phase. With the loading of CdS on to the BiOCl/Bi 2 O 3 heterojunction composite photocatalyst, the photocatalytic activity of the CdS/BiOCl/Bi 2 O 3 composite structure has been appreciably improved for the decomposition of 2-propanol (IPA) in gas phase and salicylic acid (SA) in aqueous phase under visible light irradiation (λ ≥ 420 nm). The amount of loading of CdS nanoparticles was optimized to 2 mol% CdS/BiOCl/Bi 2 O 3 . Compare to bare BiOCl/Bi 2 O 3 photocatalyst, CdS/BiOCl/Bi 2 O 3 heterojunction demonstrated 2 times decomposition of IPA in gas phase and 1.8 times of SA in aqueous phase after 120 min. of visible light irradiation. At the same time, with this composition the evolution of CO 2 from degradation of IPA was 1.9 times higher than that of BiOCl/Bi 2 O 3 composite. The enhanced photocatalytic efficiency is deduced from the electron (eˉ) and hole (h + ) transfer among the component semiconductor nanoparticles Bi 2 O 3 , BiOCl and CdS due to their relative energy band positions. Several experimental evidences were also provided to confirm the electron-hole transfer among the semiconductors and a mechanistic way has been proposed. [ABSTRACT FROM AUTHOR]

In this study, rhodium-antimony co-doped TiO 2 nanorods and titanate nanotube (RS-TONR/TNT) composite was hydrothermally synthesized from rhodium-antimony co-doped TiO 2 nanorod (RS-TONR). Initially, RS-TONR and RS-TONR/TNT samples were photocatalytic inactive under visible light irradiation ( λ ≥420 nm). Catalytic performance of RS-TONR/TNT composite was improved by surface protonation and then post-calcination process. Calcination of protonated sample has transformed most titanate nanotubes of RS-TONR/TNT into anatase TiO 2 nanoparticle (TNP) in the composite. This composite contains admixture of both rutile phase of TiO 2 nanorods and TiO 2 nanoparticle (48/RS-TONR/TNP-400). The photocatalytic activity of 48/RS-TONR/TNP-400 composite was increased for decomposition of organic compounds under visible light irradiation. In the composite structure rutile phase of TiO 2 nanorods composed of rhodium-antimony co-doping is responsible for absorption of visible light irradiation and low band edge position of TNP facile the transport of conduction band charge carriers. At next step, 48/RS-TONR/TNP-400 sample was loaded with copper oxide as co-catalyst. The synergistic effect of calcination and co-catalyst was observed as Cu(3 wt%) 48/RS-TONR/TNP-400 sample showed the highest photocatalytic performance for degradation of organic pollutants. Also, Cu(3 wt%)-48/RS-TONR/TNP-400 photocatalyst was successfully applied for disinfection of both Gram-negative and Gram-positive bacterial pathogens such as E. coli, S. typhimurium and L. monocytogenes . [ABSTRACT FROM AUTHOR]

A unique CdS/Fe3O4/rGO composite photocatalyst is successfully synthesized by the microwave method. It displays promising photocatalytic activity towards the photo-degrading of tetracycline (TC) in aqueous solution, the degradation rate of TC is 69% with adding 0.1g CdS/Fe3O4/rGO photocatalyst into 20mg/L tetracycline for 2h under visible light irradiation. Furthermore, the mechanism was systematically investigated by active species trapping experiment. It can be known that the major active species in the photodegradation process and the possible process of charge transfer for CdS/Fe3O4/rGO was proposed based on the experimental results. The as-prepared samples were carefully evaluated by XRD, TEM, XPS, VSM, PL spectra, Raman spectrometer. The TEM figure reveals the morphology and microstructure of Fe3O4, Fe3O4/rGO, CdS/Fe3O4/rGO. It can be seen that the pure Fe3O4 sample displays similar size and shape sphere (Fig. A); the rGO is like thin films loaded with Fe3O4, which indicates that the sample is successfully composed of well-dispersed spherical particles (Fig. B). Figures C and D show the morphology of the CdS/Fe3O4/rGO NPs at different magnifications. [ABSTRACT FROM AUTHOR]

A series of Ag3PO4/BiOCOOH composite photocatalysts have been successfully synthesized by a simple in situ ion precipitation method. The crystallinity, morphology, microstructure, composition and optical property were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), energy dispersive spectrum (EDS), Fourier transform infrared spectrometer (FT-IR), X-ray photoelectron spectroscopy (XPS), UV-Vis diffuse reflectance spectrophotometer (DRS). The as-prepared catalysts exhibited excellent photocatalytic activity for the degradation of RhB and MB under visible light irradiation, the 2:1 Ag3PO4/BiOCOOH exhibited the best photocatalytic activity. By adding different free radical scavengers, the catalytic mechanism was discussed. In the process of degradation of RhB, holes (h is the main active species, O played a certain active role, OH played a small role. In the process of degradation MB, holes (h is the main active species too, O also played a certain active role, OH almost does not work. Ag3PO4/BiOCOOH composite photocatalysts with different molar ratio have been successfully synthesized via a simple in situ ion precipitation method. The formed heterostructure between BiOCOOH and Ag3PO4 can improve the separation efficiency of photo-induced electrons and holes. The as-prepared Ag3PO4/BiOCOOH composites exhibited excellent photocatalytic activity in the degradation of RhB and MB under visible-light illumination. [ABSTRACT FROM AUTHOR]

A hybrid nanomaterial comprising of one-dimensional W 18 O 49 nanowires grown on two-dimensional g-C 3 N 4 sheets was prepared by a facile solvothermal process. Photocatalytic activity of these materials for H 2 generation under visible light was evaluated. The optimum efficiency of W 18 O 49 /g-C 3 N 4 composite photocatalyst at a mass content of 30% was up to 4.5 times as high as that of the pure g-C 3 N 4 . The significantly enhanced performance of W 18 O 49 /g-C 3 N 4 composites was mainly attributed to the synergistic effect between the interface of W 18 O 49 nanowires and g-C 3 N 4 sheets, involving stronger light absorption in the visible range, faster transfer and more efficient separation of the photo-generated electron-hole pairs. In short, the W 18 O 49 /g-C 3 N 4 hybrid nanomaterial was demonstrated to be an effective photocatalyst for H 2 production. [ABSTRACT FROM AUTHOR]

In this work, thermally exfoliated graphene nanosheets (GNS) were employed to prepare novel Ag3PO4-GNS composite photocatalysts by a facile chemical precipitation approach. The as-prepared Ag3PO4-GNS composite photocatalysts were characterized by X-ray diffraction (XRD) pattern, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Raman spectroscopy, thermogravimetric (TG) analysis, ultraviolet-visible diffuse reflectance spectroscopy (DRS) and photoluminescence (PL) spectra. It was found that the Ag3PO4 particles were well deposited on the surfaces of GNS. Compared with bare Ag3PO4 and Ag3PO4-rGO composite, the Ag3PO4-GNS composite exhibited enhanced photocatalytic activity for the photodegradation of rhodamine B (RhB) under visible light irradiation. The photocatalytic degradation rate of Ag3PO4-GNS composite was 1.7 times that of bare Ag3PO4 and about 1.3 times that of Ag3PO4-rGO for the degradation of RhB. Furthermore, the photocatalytic stability of Ag3PO4-GNS composite was also greatly enhanced. This enhanced photocatalytic activity and stability could be ascribed to the positive synergetic effects between the Ag3PO4 particles and GNS sheets, which could provide a greater number of active adsorption sites, suppress charge recombination and reduce the serious photocorrosion of Ag3PO4. Moreover, the photocatalytic degradation of RhB over Ag3PO4-GNS composites was also optimized, suggesting that the optimal amount of GNS in the composites was 11.4wt.%. This work shows a great potential of Ag3PO4-GNS composite for environmental treatment of organic pollutants. Thermally-exfoliated graphene nanosheets (GNS) were employed for the first time to prepare Ag3PO4-GNS composite photocatalysts by a chemical precipitation approach. Compared with bare Ag3PO4 and Ag3PO4-rGO composite, the Ag3PO4-GNS composite exhibited enhanced photocatalytic activity and stability for rhodamine B photodegradation under visible light irradiation. This enhanced photocatalytic activity and stability was ascribed to the positive synergetic effects between Ag3PO4 and GNS, which could provide much more active adsorption sites, suppress charge recombination and reduce the serious photocorrosion of Ag3PO4. [ABSTRACT FROM AUTHOR]

A visible light-driven BiO-TiO composite photocatalyst was prepared by an ethylene glycol-assisted sol-gel method in which ethylene glycol acted as a polycondensation agent to capture metal ions by reacting with bismuth and titanium sources via a complex polycondensation pathway. The photocatalyst was characterized by X-ray photoelectron spectroscopy, X-ray diffraction, acquisition of N adsorption-desorption isotherms, transmission electron microscopy, and UV-visible diffuse reflectance spectroscopy. The results revealed that the BiO-TiO composite was of smaller particle size, greater specific surface area, and had stronger absorbance in the visible light region than pure TiO. The photocatalytic activity of the as-prepared catalyst was evaluated by degradation of rhodamine B under visible light irradiation ( λ > 400 nm); the as-prepared BiO-TiO composite was substantially more active than pure TiO. This was ascribed to the high surface area and the heterojunction structure. [ABSTRACT FROM AUTHOR]

Abstract: Porous peanut-like BiVO4 and BiVO4/Fe3O4 submicron structures were synthesized by a template-free hydrothermal process at 160°C for 24h. The as-synthesized samples were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometer (VSM) and UV–vis spectroscopy. The photocatalytic activity of BiVO4 and BiVO4/Fe3O4 submicron structures were evaluated for the degradation of Rhodamine B (RhB) and methylene blue (MB) under visible light irradiation with and without the assistance of H2O2. According to the experimental results obtained, porous peanut-like BiVO4/Fe3O4 composite photocatalyst shows higher photocatalytic activity in the H2O2-assisted system under visible light irradiation compared to BiVO4. Recycling test on the BiVO4/Fe3O4 composite photocatalyst for the degradation of RhB under visible light irradiation indicates that the composite photocatalyst is stable in the H2O2-assisted system in five cycles. Therefore, this composite photocatalyst will be beneficial for efficient degradation of organic pollutants present in water and air under solar light. [Copyright &y& Elsevier]

[Display omitted] • Ag/Cu 2 O is synthesized by directly reducing Ag+ to Ag at room temperature and constant pressure and supporting it on Cu 2 O. • The Ag particles can generate plasmon resonance, which significantly enhances the light absorption performance of the Ag/Cu 2 O composite catalys. • Ag acts as an electron trap to improve the separation efficiency of photoelectrons-holes. In this experiment, Ag/Cu 2 O heterojunction was obtained by directly reducing Ag+ at room temperature in one step, and evaluated its performance of degrading pollutants. Through comparative photocatalytic activity experiments, it can be seen that the degradation effect of the catalyst is much higher than that of Cu 2 O nanocubes. The amount of Ag particles contained can be controlled by controlling the sum of silver nitrate, and it is found that Ag/Cu 2 O-3 has the optimal ratio. Through a series of characterization of the prepared samples, it can be concluded that the main reason for the improvement of the photocatalytic performance of the composite photocatalyst is that the presence of Ag improves the transference of photoelectrons, and then accelerates the separation of photoelectrons-holes of Cu 2 O. In addition, the presence of Ag particles expands the absorption range of Cu 2 O in visible light region, thereby improving the photocatalytic performance. [ABSTRACT FROM AUTHOR]

Antibiotic pollutants have posed a huge threat to the ecological environment and human health. In this work, α-Bi 2 O 3 /g-C 3 N 4 composite was prepared and coupled with H 2 O 2 for the rapid and efficient degradation of doxycycline (DOX) in water under visible light irradiation. The composite exhibited enhanced photocatalytic activity and 80.5% of DOX could be degraded in 120 min. The addition of H 2 O 2 significantly improved the degradation efficiency of DOX under visible light, resulting in 79.0% of it degraded within 30 min, and the degradation rate constant of DOX was 3.6 times than that without H 2 O 2. On the one hand, the Z-scheme heterojunction of α-Bi 2 O 3 /g-C 3 N 4 promoted the separation rate of photogenerated electron-hole pairs, thereby enhancing the photocatalytic activity of the composite. On the other hand, the improvement of photocatalytic efficiency also benefited from the extra hydroxyl radicals generated by the reaction of photogenerated electrons with H 2 O 2 in the photocatalytic system. Free radicals trapping experiments and electron spin resonance tests proved that ▪ played prominent role in the degradation process. After adding H 2 O 2 , OH also became important active species. Cyclic degradation experiments demonstrated the recyclability of the composite photocatalyst in DOX elimination applications. This work provides an efficient, clean, and recyclable purification strategy for removing antibiotic contaminants from water. • The system of α-Bi 2 O 3 /g-C 3 N 4 coupled with H 2 O 2 was constructed. • Z-Scheme electron transfer mechanism was proposed. • 79.0% doxycycline was degraded within 30 min in the presence of H 2 O 2. [ABSTRACT FROM AUTHOR]

Zn 2 GeO 4 /rGO composite photocatalysts were prepared by hydrothermal method with Zn 2 GeO 4 and GO as precursors, and ethanol/water solvent as a reducing agent. Reduced graphene oxide was combined with Zn 2 GeO 4 nanorods in order to improve photocatalytic activity of Zn 2 GeO 4 through improving its surface area, adsorption capacity, charges separation and transportation ability. Then the composite photocatalysts were characterized by XRD, FESEM, EDS and UV–vis DRS. RhB synthetic dye wastewater was used as the target to investigate the effect of each reaction parameter on the degradation rate; the catalytic performance stability of the composite photocatalyst was investigated under the obtained optimal reaction conditions; and the reaction kinetics and reaction mechanism of the synthetic wastewater treatment process were preliminarily analyzed. The study shows that the Zn 2 GeO 4 /rGO composite photocatalyst prepared by hydrothermal method has better photocatalytic activity under xenon light illumination, and the wastewater treatment process conforms first-order reaction kinetic characteristics; during the treatment, the dye molecules are directly degraded by the composite photocatalyst, and no other luminescent groups are produced. The Zn 2 GeO 4 /rGO composite photocatalyst with good photocatalytic activity and stability under visible light irradiation can be prepared by hydrothermal method for dye wastewater treatment. Image 1 • Nano-Zn 2 GeO 4 /rGO composite photocatalyst were prepared by hydrothermal method. • Nano-Zn 2 GeO 4 /rGO were used to treat wastewater as photocatalyst first time. • Zn 2 GeO 4 photocatalytic performance were enhanced due to the rGO composited. [ABSTRACT FROM AUTHOR]

Co-doped NiTiO3/g-C3N4 composite photocatalysts were prepared by a modified Pechini method to improve their photocatalytic activity toward methylene blue photodegradation under visible light irradiation. The combination of Co-doped NiTiO3 and g-C3N4 and Co-doping into the NiTiO3 lattice synergistically enhanced the photocatalytic performance of the composite photocatalysts. X-ray photoelectron spectroscopy results for the Co-doped NiTiO3/g-C3N4 composite photocatalysts confirmed Ti-N linkages between the Co-doped NiTiO3 and g-C3N4. In addition, characteristic X-ray diffraction peaks for the NiTiO3 lattice structure clearly indicated substitution of Co into the NiTiO3 lattice structure. The composite structure and Co-doping of the C-x composite photocatalysts (x wt % Co-doped NiTiO3/g-C3N4) not only decreased the emission intensity of the photoluminescence spectra but also the semicircle radius of the Nyquist plot in electrochemical impedance spectroscopy, giving the highest kapp value (7.15 × 10−3 min−1) for the C-1 composite photocatalyst. [ABSTRACT FROM AUTHOR]

• A nitric oxide removal coating was constructed by loading doped TiO 2 /AC photocatalyst on waterborne acrylic coating. • Under visible light irradiation, the NO degradation efficiency of doped TiO 2 /AC coating was 45.8 % in 2 h, and only decreased by 5.8 % after 5 cycles. • UV stability of doped TiO 2 /AC coating was investigated, and the mechanism of improving UV stability was proposed. • After 42 d UV aging and single water flushing, the NO removal efficiency of doped TiO 2 /AC coating still reached 36.7 % and exhibited excellent UV stability. Based on the porous structure of activated carbon (AC) and the photo-oxidation behavior of TiO2, a visible-light-responsive photocatalytic coating with UV stability was constructed by loading Fe/N/Co-TiO2@AC (DTC) on waterborne acrylic coating. The DTC with adsorption and degradation synergistic effect was prepared by a simple mechanochemistry method and characterized by UV–vis, SEM, XRD, and BET. The nitric oxide (NO) removal efficiency of DTC was 51.6 % under visible light in 2 h. Besides, under the same conditions, the NO removal efficiency of the DTC coating still reached 45.8 %. Further, to investigate the UV stability of DTC coating, different coatings were prepared with the same dosage of DTC, TiO 2 @AC (TC), and TiO 2. The UV stability of the coatings was tested with a color difference, degree of chalking, adhesion strength, hardness, and impact resistance as evaluation indicators. The results showed that the DTC coating exhibited the best UV stability. The photooxidation of organic binder on the coating surface before and after aging was micro-characterized by SEM and FT-IR, and the UV stability improvement mechanism was revealed. [ABSTRACT FROM AUTHOR]

In this paper, a novel heterojunction material was synthesized of C 3 N 4 via doping with π-deficient conjugated pyridine ring molecules (2,6-diaminopyridine) and BiOCl by ultrasound-assisted method. First, doping C 3 N 4 with 2,6-diaminopyridine can reduce the structural integrity and orderliness of C 3 N 4 , and reduce the number of structural fragments, Which makes C 3 N 4 have more reactive sites. And then BiOCl nanosheets were grown on the surface of the modified C 3 N 4 nanosheets to obtain a new heterojunction material composed of modified C 3 N 4 doped with π-deficient pyridine ring molecules and BiOCl by the co-precipitation method. At last, the degradation of methyl orange (MO) by BiOCl, C 3 N 4 , modified C 3 N 4 doped with 2,6-diaminopyridine, and a series of C 3 N 4 doped with 2,6-diaminopyridine and BiOCl composite heterojunction materials under visible light was studied. X-ray diffraction (XRD), scanning electron microscope (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET), ultraviolet visible diffuse reflection (UV–Vis DRS) and transient photocurrent densities, and electrochemical impedance spectroscopy (EIS) were used to analyze the structure, morphology, and photogenerated charge transfer characteristics of samples. The experimental results show that the new heterojunction composite materials has better photocatalytic activity compared with pure BiOCl, C 3 N 4 , and modified C 3 N 4 doped with 2,6-diaminopyridine. In addition, the degradation performance of methyl orange with different mass ratios of composite materials is also different. When the mass ratio of C 3 N 4 doped with 2,6-diaminopyridine to BiOCl is 1:2, The composite material exhibits the best photocatalytic performance, which may be related to the synergistic effect of the modified C 3 N 4 doped with 2,6-diaminopyridine and BiOCl. Based on the band structure and active species experiments, the reasons for the enhanced photocatalytic activity are discussed, and the possible degradation mechanisms are proposed. The research in this paper provides an effective new way to construct new heterojunction materials. Unlabelled Image • A novel heterojunction material was synthesized of C 3 N 4 via doping with π-deficient conjugated pyridine ring molecules (2,6-diaminopyridine) and BiOCl by ultrasound-assisted method. • The absorption edge of C 3 N 4 doped with π-conjugated pyridine ring gradually red-shifted from 460 nm to 700 nm in the visible region, indicating that π-conjugated pyridine ring modified carbon nitride can effectively improve the light absorption performance of the samples. • Degradation MO repeatability experiments under the visible light proved that the 0.5-C 3 N 4 -DPY/BiOCI composite material has good visible light catalytic stability. [ABSTRACT FROM AUTHOR]

• MS-ZSO composite was prepared by a simple hydrothermal route. • The MS-ZSO composites showed outstanding visible-light photocatalytic activity for degradation of TC. • The possible photodegradation pathways of TC over MS-ZSO was proposed based on the intermediates detected by LC–MS. In this study, MoS 2 /ZnSnO 3 (MS-ZSO) composite photocatalyst with loading MS nanosheets onto the surface of porous ZSO microcubes was synthesized using a simple hydrothermal route. The prepared MS-ZSO composite can be easily excited under visible light, and 3 % MS-ZSO exhibits an outstanding photo-degradation (>80 % in 60 min) and mineralization performance (>42 % in 60 min) of the tetracycline. A remarkable improvement in the photocatalytic activity of MS-ZSO composite derived from a positive synergistic effect of well-matched energy level positions, increasement the absorption of visible light, prolonged life time decay and improved interfacial charge transfer between MS and ZSO. In-depth investigation on charge carrier separation mechanism toward MS/ZSO composite under visible light was proposed, which was further evidenced by capture experiments and electron spin resonance (ESR) techniques. Furthermore, the corresponding intermediates of tetracycline degradation over MS-ZSO composites were inspected by liquid chromatography-mass spectrometry (LC–MS) analysis, and the possible degradation paths were proposed. [ABSTRACT FROM AUTHOR]