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A novel Ag3VO4/CoWO4 (AgCoO) p–n heterostructure was designed and prepared by an in situ growth method. The physicochemical properties of the as-prepared materials were characterized by multiple techniques, and the photocatalytic performances in Cr(VI) reduction and TC degradation were also evaluated under visible-light irradiation. The optimal AgCoO0.20 exhibited excellent Cr(VI) reduction activity (98.5% removal rate) and TC degradation activity (71.4% removal rate). The enhanced Cr(VI) reduction and TC degradation performances were attributed to fast transportation and efficient separation of the charge carriers due to the synergistic effect of the sufficient interfacial contact and the interaction between CoWO4 and Ag3VO4 induced by the formation of the p–n heterostructure. Ultimately, the possible enhanced photocatalytic mechanism over the Ag3VO4/CoWO4 p–n heterostructure composite was also proposed. [ABSTRACT FROM AUTHOR]

Polypyrrole-decorated BiOBr composites (BiOBr/PPy) were synthesized by in-situ polymerizations, which exhibited an excellent catalytic performance in visible-light driven Cr(VI) reduction and degradation of dye methylene blue (MB). PPy not only acted as a photosensitizer to harvest more photon for photocatalysis, but also an electric conductor for accelerating the transfer and separation of e −- h + pairs. In the as-prepared composites, the BiOBr/PPy 1.5 presented the excellent photocatalytic activity, which could achieve nearly 100 % removal efficiencies for the Cr(VI) reduction after 40 min and MB degradation within 50 min. The enhanced photocatalytic performance was ascribed to the decorating of PPy on BiOBr for maximizing the light absorption, migration and separation of photogenerated e −- h + pairs. Moreover, the possible photocatalytic mechanisms were put forward for Cr(VI) reduction and MB degradation over the BiOBr/PPy, respectively. The photogenerated electrons of PPy were readily transferred to BiOBr, and the photogenerated holes kept in PPy, resulting in a significant enhancement of the photocatalytic activity. Such designed structure offered a new way to construct a spatial separation system of charge carriers for high-efficient photocatalysts in environmental remediation. In this study, the BiOBr/PPy composites were synthesized by in-situ polymerizations, which showed the highest photocatalytic performance in Cr(VI) reduction (nearly100 % in 40 min) and MB degradation (100 % in 50 min) under visible-light. [Display omitted] • An efficient and stable BiOBr/PPy composite photocatalyst was fabricated. • Boosting the separation efficiency of of e −- h + pairs was achieved by coupling BiOBr with PPy. • Cr(VI) reduction or MB degradation is achieved by BiOBr/PPy under visible-light. • The optimal BiOBr/PPy showed the excellent photo-oxidation/reduction activity. [ABSTRACT FROM AUTHOR]

To improve the light-harvesting capability and electron-hole separation efficiency, a novel heteroatom-introduced Bi 2 WO 6 photocatalyst (OV–Bi 2 WO 6) with oxygen vacancies (OVs) was prepared via the partial substitution of O2− by S2− anions. The OV-Bi 2 WO 6 showed high photocatalytic properties in photo-oxidation/reduction reactions under visible-light. The OVs content could be controlled by adjusting the sulfur source amount, and the optimal OV (0.9) -Bi 2 WO 6 with suitable OVs had a high photocatalytic activity with 97.6% of MO removal and 88.2% of Cr(VI) removal efficiency. Density functional theory (DFT) calculations verified that the OVs in Bi 2 WO 6 could induce a new defect level to decrease the bandgap energy and accelerate the carrier separation/migration. Furthermore, the possible photocatalytic mechanisms for MO degradation and Cr(VI) reduction over the OV-Bi 2 WO 6 were proposed, respectively. The present work helped us to better understand the enhancement mechanism of OVs in Bi-based semiconductors and paved the way to develop high-performance photocatalysts for environmental remediation. [ABSTRACT FROM AUTHOR]

A novel photocatalytic antibacterial agent, i.e., phosphorus and sulfur codoped carbon nitride (PSCN) nanosheets was synthesized by a simple two-step template-free method. Compare to g-C 3 N 4 , PSCN achieved a remarkable improvement in photocatalytic antibacterial performance. [Display omitted] • Phosphorus and sulfur codoped carbon nitride (PSCN) nanosheets was prepared by a simple two-step template-free method. • Codoping and stripping enhanced the photocatalytic efficiency. • PSCN have a remarkable improvement in photocatalytic antibacterial performance. • PSCN efficiently heal S. aureus -infected wounds in rabbits. In this study, we report a novel photocatalytic antibacterial agent, i.e., phosphorus and sulfur codoped carbon nitride (PSCN) nanosheets, which was synthesized by a simple two-step template-free method that enhances the photocatalytic efficiency and antibacterial ability of antibacterial agents in terms of healing wound infections. By innovatively introducing the dopants of adenosine triphosphate and thiourea, P, S successfully doped into the well-preserved heptazine units of g-C 3 N 4 , P covalently bonded with N, and S existed as S2- and sulfur oxides (SO x) with relatively weak peak. In particular, under visible light irradiation, PSCN tended to generate more reactive oxygen species (mainly h+ and •O 2 −) owing to its enhanced photocatalytic ability. PSCN in turn manifested superior antibacterial performance compared with g-C 3 N 4. 99.2% of Staphylococcus aureus (S. aureus) were killed on exposure to a 300 W Xenon lamp for 2.5 h cocultivation with PSCN, and 97.0% Escherichia coli (E. coli) were dead for 2 h, while the biocompatibility of PSCN is guaranteed. Moreover, a 7-day treatment effect could be observed in an S. aureus -infected wound model established in rabbits. Briefly, PSCN might blaze new trails in bacterial infection treatments owing to its significant antibacterial and wound-healing properties. [ABSTRACT FROM AUTHOR]

Constructing heterostructures to restrain the rapid recombination of photogenerated e −- h + pairs is believed to be an effective strategy to improve photocatalytic redox efficiency, but the inferior contact interface and low charge transfer efficiency still restrict the heterostructures applications. Herein, for improving the photocatalytic efficiency in the Cr(VI) reduction and MB degradation under visible-light, tiny Bi 2 WO 6 (BWO) nanosheets were confined on the CoAl-LDH (LDH) surface to construct the BWO/LDH S-scheme heterostructure with strong internal electric field due to spatial confinement effect. The incorporation of BWO broadened the photo-absorption range and effectively promoted the separation of photo-generated charges, leading to the dramatical enhancement in photocatalytic redox activity of the LDH. Experimental results and theoretical calculations showed that the internal electric field endowed a powerful driving force for vectoral migration of charge carriers between BWO and LDH, and thus promoted the transfer and spatial separation of charge carriers through S-scheme pathway. Benefitted from the S-scheme heterostructures, the perfect BWO/LDH 2.0 delivered a high removal efficiencies of 85.1 % in Cr(VI) reaction and 92.1 % in MB degradation, which reaction rates were 2.0 and 1.5 times higher than those of the LDH under visible-light, respectively. This work suggested a feasible approach to construct LDH-based photocatalysts with S-scheme heterostructures. [Display omitted] • Bi 2 WO 6 /CoAl-LDH S-scheme heterostructure was prepared. • The redistribution of photogenerated e −- h + pairs in the heterostructure followed S-scheme mechanism. • The built-in internal electric field was verified by XPS, ESR and DFT calculation. • High Cr(VI) reduction and MB degradation efficiencies were achieved under visible-light. [ABSTRACT FROM AUTHOR]

The Cu 2 O/ZnTi-LDH (Cu 2 O/LDH) composite was synthesized via Cu-doping into the ZnTi-LDH followed by in-situ reduction strategy for Cr(VI) reduction and tetracycline (TC) degradation under visible-light, where the Cu 2 O nanoparticles (NPs) were homogeneously embedded onto the LDH host layers through in-situ reducing the Cu-doped ZnTi-LDH (CuZnTi-LDH). The optical, photoelectric and photocatalytic performances of the Cu 2 O/LDH could be adjusted by changing the Cu-doping amount in the CuZnTi-LDH. As expected, the optimal Cu 2 O/LDH 0.10 exhibited high photocatalytic activities for the Cr(VI) reduction (95.5% Cr(VI) removal) and TC degradation (71.6% TC removal) after 120 min. Based on the experimental and density functional theory (DFT) calculation results, a possible p-n heterostructure formation between Cu 2 O and ZnTi-LDH as well as the transfer route of photogenerated electron-hole pairs toward for Cr(VI) reduction and TC degradation were proposed. This work may provide a rational and facile strategy for improving the LDH-based materials in catalytic oxidation-reduction reactions. The schematic diagram of the evolution process of the Cu 2 O/ZnTi-LDH, and photocatalytic of Cr(VI) reduction and TC degradation under visible-light. [Display omitted] • Cu 2 O NPs were evenly embedded onto the LDH host layers by in-situ reduction strategy. • Cu 2 O self-photooxidation was restrained due to the high dispersion of Cu 2 O NPs. • The p-n heterostructure provided a new path for transfer and separation of electron-hole pairs. • Cu 2 O/ZnTi-LDH displayed excellent Cr(VI) reduction and TC degradation performances. [ABSTRACT FROM AUTHOR]