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It is a practical way to raise the efficiency of photocatalysis by using oxygen vacancy defect modified materials. In this experiment, a Z‐scheme BOA composite photocatalyst with defect structure was prepared by hydrothermal in situ precipitation method. The optimal ratio of 1.5 BOA showed excellent photocatalytic degradation performance for MO, TC and CIP under visible light irradiation, and maintained good structural stability and circulation rate after five cycles. The increased photocatalytic activity of the composite can be explained to the heterojunction interface's synergistic effects and the quicker electron hole transit rate caused by the surface oxygen vacancy defect. XPS and EPR confirmed the existence of anoxic structure in the composite, PL and photocurrent confirmed the high electron hole transfer rate. The active species that contributed to the degradation process were validated by the active species capture experiment and ESR. LC–MS speculated the possible degradation path of CIP. Finally speculated the reaction mechanism of Z‐scheme BOA composite photocatalyst. Using the anoxic structure of BiO2−X to form a Z‐scheme heterostructure with Ag3PO4, the oxygen vacancy as the electron capture center and active site is conducive to improving the photogenerated electron transfer rate, thereby improving the structural stability and photocatalytic performance of the complex. [ABSTRACT FROM AUTHOR]

An excellent ternary Z-scheme photocatalytic heterojunction of g-C3N4 nanosheet/WO3/graphene oxide (CWG) was prepared by in-situ growth of WO3 during thermal exfoliation bulk g-C3N4 to g-C3N4 nanosheet, followed by electrostatic self-assembly of graphene oxide (GO) and g-C3N4 nanosheet in the HNO3 solution. The photocatalytic performance was evaluated by the degradation of rhodamine B (RhB) under visible light irradiation. The CWG heterojunction exhibited outstanding photocatalytic efficiency for RhB degradation, which was about 4.6 and 23 times that of CN and WO3, indicating the introduction of GO and WO3 improved the capability of the photocatalysis due to an efficient charge separation and transfer between g-C3N4 nanosheets and WO3. In addition, the possible for the enhancing photocatalytic mechanism was revealed based on the active species trapping and ESR analysis. [ABSTRACT FROM AUTHOR]

A new type of visible light Z‐scheme Bi2O3‐Ag3PO4 composite photocatalyst was created in this work using a simple in‐situ precipitation process. On this basis, the morphology, optical properties and electrochemical performance of the photocatalyst were studied by N2 adsorption‐desorption analysis and XRD, FT‐IR, XPS, SEM, TEM, UV‐vis DRS, PL, EIS, and other characterization methods. To further explore the photocatalytic performance of the composites, visible light degradation experiments were carried out on the antibiotic TC and the organic dyes MB and MO. The results show that the 0.025BA composite material exhibits higher photocatalytic performance than other comparative samples. In addition, the 0.025BA composite after five cycles of experiments also has a satisfactory photodegradation rate. The active species capture experiment and ESR showed that the active species h+, ⋅O2− are the main factors affecting the photocatalytic degradation, and ⋅OH played a minor role. The intermediates and possible decomposition pathways of TC were illustrated through LC–MS technology. Finally, the possible photocatalytic reaction mechanism was speculated. On the whole, the high photocatalytic activity of the 0.025BA composite is perhaps the result of the formation of its Z‐scheme heterojunction, which enables fast transfer and high separation of photogenerated carriers at the heterojunction interface, and also accelerates the rate of redox reactions on electron‐hole pairs. [ABSTRACT FROM AUTHOR]

A novel binary ZnO/g‐C3N4 nanosheets (ZCN)‐X (X=10, 20 and 30 wt% of ZnO) composites were prepared by a simple hydrothermal method. The properties of the samples were characterized by XRD, FT‐IR, SEM, UV‐vis, PL, XPS and electrochemistry, and the photodegradation effect of the samples on MO were evaluated. The FT‐IR spectra revealing that the conjugated system between g‐C3N4 and ZnO was generated. The UV‐vis diffuse reflectance spectra showed that the introduction of CNNs reduces the band gap of binary composites and broadens the visible light absorption range of the samples. The fluorescence analysis results suggested that the conjugated system between g‐C3N4 and ZnO was generated. The phtotcatalysis results showed that ZCN‐20 has strong photodegradation activity and lower luminescence intensity. After irradiation for 120 min under visible light, it gives a degradation rate of 98.5 % with good stability. The construction of heterojunction between CNNs and ZnO nanoparticles accelerates electron transfer and inhibits the recombination of photogenerated electron hole pairs, and the synergistic effect of CNNs and ZnO greatly enhanced the photocatalytic performance of samples. [ABSTRACT FROM AUTHOR]

In this study, the composite catalysts with the heterojunction between DUPG and BiOBr were used to degrade methyl orange (MO), and a g‐C3N4‐based ternary composite catalyst was developed. In our previous work, we prepared a D‐C3N4/U‐C3N4 isotype heterojunction with ordered mesoporous (DUPG) by co‐mixed calcination and hard template method. On this basis, we prepared DUPG/BiOBr nanoparticle uniformly distributed on DUPG nanosheets by coprecipitation self‐assembly method. The hybrids form a tightly coupled heterojunction that enhances the photoactivity and photostability of the DUPG/BiOBr composites. The results show that this tight coupling is beneficial, which facilitates the charge transfer between DUPG and BiOBr, thus promoting the effective separation of photogenerated electron hole pairs. Under visible light irradiation, the methyl orange conversion of the sample has higher photocatalytic reduction activity than BiOBr and DUPG, and its excellent photocatalytic activity is improved by light‐harvesting ability, increased specific surface area, active species and target pollution. [ABSTRACT FROM AUTHOR]

In order to develop highly efficient visible-light induced photocatalysts, the zinc oxide (ZnO) hybridized with mesoporous graphitic carbon nitride (mpg-C 3 N 4 ) nanocomposite photocatalysts (mpg-C 3 N 4 /ZnO) were synthesized through simple one-step calcination in this paper. The physicochemical properties of the synthesized samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), N 2 physical adsorption, UV–vis diffuse reflectance spectra (DRS), and photoluminescence spectra (PL). Subsequently, the photocatalytic performance of mpg-C 3 N 4 /ZnO was evaluated by photocatalytic degradation of methyl orange (MO) aqueous solution under visible-light irradiation. The photocatalytic activities of the resultant mpg-C 3 N 4 /ZnO nanocomposites were enhanced outstandingly and much higher than that of pure mpg-C 3 N 4 and ZnO. The improved photocatalytic activities of the mpg-C 3 N 4 /ZnO nanocomposites were ascribed to the exaltation of the separation efficiency of photoinduced electron-hole pairs, resulting from the heterojunction established between the interfaces of mpg-C 3 N 4 and ZnO. [ABSTRACT FROM AUTHOR]