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In this study, N and P were used to double doping MXene to obtain N,P-MXene with increased layer spacing and structural defects. Schottky junction N,P-MXene/ZnIn 2 S 4 photocatalysts with tight interfacial contacts were obtained by in situ growth of flower-like ZnIn 2 S 4 nanosheets. The N,P-MXene interlayer spatial structure facilitates the uniform dispersion of ZnIn 2 S 4 and the exposure of the active site. The formation of the Schottky barrier enables the two closely contacted interfaces to form a carrier transport channel, which accelerates the arrival of the charge carriers on the catalyst surface for REDOX reactions. 50 N,P-MXene/ZIS degraded 86.1 % of CIP and 93.9 % of MO. In addition, after several cycling experiments, it was proved that the photocatalyst had good structure and chemical stability. The photocatalytic mechanism was demonstrated by UPS and radical quenching experiments. N,P-MXene/ZnIn 2 S 4 is not only suitable for pH = 7–11, but also for salt solution wastewater containing higher concentrations of NaCl or KCl. Therefore, the construction of heteroatom doped N,P-MXene/ZnIn 2 S 4 Schottky junction photocatalysts with excellent photocatalytic degradation performance is of profound significance for the treatment of pollutants. [Display omitted] • N and P elements double doping MXene to obtain N,P-MXene with increased layer spacing and defective structure. • N,P-MXene/ZIS Schottky barrier composite photocatalyst degraded CIP (86.1 %) and MO (93.9 %) with high efficiency. • Schottky barrier promotes the formation of charge carrier transport channels, which is beneficial to the separation of photogenerated electron and hole pairs. [ABSTRACT FROM AUTHOR]

Ce/N co-doped TiO 2 /NiFe 2 O 4 /diatomite (CN-TND) hybrid catalyst was prepared via sol-gel method. This ternary composite combined the advantages of three components: adsorption capability of diatomite (Dt), visible-light-driven photoactivity of Ce/N co-doped TiO 2 (Ce/N-TiO 2 ), and magnetic recyclability of ferrite NiFe 2 O 4 . The physicochemical properties of CN-TND were characterized by various analytical methods. The visible-light-driven photoactivity of CN-TND was investigated by the degradation of tetracycline (TC) and disinfection of Escherichia coli ( E. coli ) under visible light irradiation, and the optimal amount of Ce dopant was determined. In addition, the kinetic data of the degradation process were obtained, and the mechanism of this process was proposed. Different scavengers detected the active species involved during the degradation process. CN-TND exhibited ferromagnetism, thus it could be simply separated from the reactor by an external magnet. The reusability test proved its excellent photocatalytic stability and recyclability. We consider it suitable for the application of wastewater treatment. [ABSTRACT FROM AUTHOR]

• Triphenylamine-porphyrin dyads are synthesized for photocatalysis. • XZP2/TiO 2 exhibits the most efficient charge separation as photoelectrode. • XZP2/TiO 2 performs the best in photodegradation of acid black and tetracycline. • Photocatalytic mechanism and interfacial charge transfer pathways are proposed. [Display omitted] Three triphenylamine (TPA) substituted dichromophoric zinc porphyrins XZP1–3 and a single zinc porphyrin ZP1 have been rationally designed to construct dye-sensitized TiO 2 nanoparticles to explore the feasibility of dichromophoric dye design for photocatalysis. TPA, N,N -diphenyl-(1,1′-biphenyl)− 4-amine and a carbazole-diphenylaniline derivative are attached to the meso -position of porphyrin core as the second chromophore. The electronic structure of the porphyrins is studied by density functional theory (DFT) calculations and the dye-sensitized composites are investigated using couples of spectral and electrochemical techniques. XZP2/TiO 2 exhibits the smallest charge transfer resistance and the longest electron lifetime among the investigated composites. The same catalyst performs the highest efficiency in photodegradation of both acid black (AB1) and tetracycline (TC) polluted water samples. Electronic paramagnetic resonance and radical quenching experiments reveal that the priority reactive species are superoxide radicals (•O 2 −) and holes (h+), suggesting the efficient charge separation at the porphyrin-sensitized TiO 2 interface. This work demonstrates the facilitated interfacial charge separation using dichromophoric dye-sensitized semiconductor particles for photodegradation and, the insights should aid in dyad design for photocatalysis application. [ABSTRACT FROM AUTHOR]

With the seriously environmental pollution, photocatalytic technology has been extensively studied for ensuring the continuous development of society. As a type of appealing semiconductor, bismuth-based materials have become a research hotspot in the field of photocatalysis due to their unique electronic structure, appropriate bandgap energy, high light quantum and outstanding electronic transmission efficiency. However, the separation and recovery of photocatalyst from reaction systems is difficult. The most promising strategy to facilitate separation process is to introduce a magnetic component. This review has mainly involved a classification, current challenges and prospects on the recent progress in fabrication of magnetic bismuth-based photocatalytic materials, as well as the list of their degrade object, dosage, initial concentration and reaction time. [ABSTRACT FROM AUTHOR]

• MnO 2 was designed as flower-like structure to obtain a larger surface area. • BiOBr and Bi metals were combined with MnO 2 to construct a heterojunction. • The magnetic core facilitated the recycling of the photocatalyst. • The core-shell structure can generate synergistic effects of different components. • Composite materials exhibited excellent dyes degradation capabilities. The flower-like Fe 3 O 4 /SiO 2 /MnO 2 /BiOBr-Bi magnetic composite photocatalyst was prepared in this work. The combination of BiOBr and Bi metal with flower-like MnO 2 constituted a heterojunction structure, which increased the specific surface area of the photocatalyst and promoted the separation of photo-generated carriers, resulting in the enhanced catalytic performance. The morphologies and the compositions of the photocatalyst were characterized in detail. Under simulated light, the degradation of organic dye methylene blue (MB) was used to research the photocatalytic activity. In the case of 15 mg photocatalyst, it was found that the photocatalytic degradation efficiency to the MB solution was 95.23% within 150 min. Moreover, the degradation rate of MB could still reach 81.11% after four cycles. The design of flower-like composites with magnetic core-shell structure provided a new method for fabricating photocatalysts having excellent catalytic performance and cyclic stability. [ABSTRACT FROM AUTHOR]