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Photocatalytic water splitting has recently attracted increasing interests for solar to chemical energy conversion. Nevertheless, the high-efficiency process for photocatalytic water splitting is driven by recombination of photogenerated electron-hole pairs and the resultant low H2productivity. Herein, we demonstrate that P-doping induced positive charge centers (Pδ+) and indium vacancies (VIn) in ZnIn2S4(ZIS) nanosheets can significantly promote photosplitting pure water to simultaneously produce H2and H2O2. Microstructural and spectroscopic analysis suggest that Pδ+and VIncan trap photogenerated electrons and holes, respectively, as a result of enhanced separation of electron-hole pairs. The optimal catalyst of P-CoNi/ZIS displays a stoichiometric H2and H2O2productivity of 1228.7 and 1105.5 μmol h−1g−1, respectively, with an apparent quantum efficiency of 6.2% at 365 nm. Impressively, H2productivity of P-CoNi/ZIS has surpassed most reported catalysts for photocatalytic pure water splitting. This work provides a unique strategy to create efficient photocatalyst for pure water splitting.

Although overall water splitting with particulate photocatalysts is considered as an ideal means towards solar-to-hydrogen conversion, practical application of the promising technique is greatly inhibited by the congenital defects including H2/O2separation and unfavorable four-electron kinetics. In this context, photocatalytic overall water splitting for simultaneous H2and H2O2generation viaa two-electron pathway can readily address these issues. Here, we report a novel CoxNiyP cluster incorporated P-doped g-C3N4photocatalyst (CoxNiyP-PCN) by a two-step phosphating method that presents such unique behavior for pure water splitting into stoichiometric H2and H2O2. The highest H2evolution rate reaches 239.3 μmol h−1 g−1, achieved over the CoNiP–PCN photocatalyst, which is among the best reported activities for overall water splitting. It is found that both P and the cluster cocatalyst are critical to the remarkably improved photocatalytic activity. Specifically, P as a substitution of C in PCN introduces a positive charge center (P+), reinforcing the chemical connection between PCN and CoNiP, in a form of P+-Pδ--Coδ+/Niδ+. This unique bridging effect, together with the extended light absorption by P doping and optimized surface redox potential by cocatalyst integration, stimulates efficient vectorial charge transfer between PCN and CoNiP and subsequent surface mass exchange. On the other hand, we also demonstrate that the well satisfied band structure of PCN can facilitate the two-electron reaction pathway. This work not only has implications for the potential use of CoNiP–PCN as potential photocatalyst for solar H2production, but also offers a new idea for pure water slitting in particulate system.

Charge separation plays a crucial role in semiconductor-based photocatalytic CO2conversion. Herein, we developed a photo-magnetic coupling reactor to manipulate a unique induced electric field, which can control carrier behavior at the minuscule and boost the photocatalytic reduction of CO2. A monolithic photocatalyst consisting of a copper foam substrate and nanosized ZnO/NiO/Au heterostructures was designed to couple the rotating magnetic field (RMF) in the reactor. Specifically, induced electric field is generated by copper foam cutting the magnetic induction line, which can increase the charge carrier density by preventing their recombination. Moreover, NiO and Au synergistically magnify the charge separation as the active sites for the oxidation and reduction reaction, respectively. The utilization rate of photogenerated electrons increases by 5.24 times after coupling RMF, with the yields of CO and CH4improved by 5.50 times and 5.18 times. This strategy of integrating the distinct RMF into the reaction provides new insights for improving photocatalytic CO2conversion.

We report efficient and simultaneous production of H2and H2O2from photocatalytic pure water splitting over a novel heterojunction photocatalyst made of red phosphorus (RP) and CoxP co-modified P-doped g-C3N4(PCN). The success relies on the formation of RP as an intermediate to link CoxP and PCN, introducing atomic-level homogeneous P-P/P-P bonds in the heterojunction. The crafted P-P/P-P bridges as unique channels enable controllable and smooth charge flow via strong electronic coupling between each component in the composite photocatalyst, endowing a boosted carrier kinetics. More significantly, RP also facilities a Z-scheme charge transfer that induces two-electron photocatalytic H2and H2O2production from pure water in 1:1 stoichiometry. The highest activity reaches 15.26 μmol h−1for bifunctional chemical evolution under simulated solar light irradiation, with the apparent quantum efficiencies (AQE) of 6.2 % at 366 nm and 3.6 % at 425 nm, without using any noble metals on 50 mg of photocatalyst. The new insights of phosphorus bridges can be applied to other composite photocatalysts for reinforced reaction kinetics towards value-added chemicals generation.