Interior and Surface Synergistic Modifications Modulate the SnNb ₂O ₆/Ni-Doped ZnIn ₂S ₄ S-Scheme Heterojunction for Efficient Photocatalytic H ₂ Evolution

Exploring photocatalysts to promote CO2 photoreduction into solar fuels is of great significance. We develop TiO2/perovskite (CsPbBr3) S-scheme heterojunctions synthesized by a facile electrostatic-driven self-assembling approach. Density functional theory calculation combined with experimental studies proves the electron transfer from CsPbBr3 quantum dots (QDs) to TiO2, resulting in the construction of internal electric field (IEF) directing from CsPbBr3 to TiO2 upon hybridization. The IEF drives the photoexcited electrons in TiO2 to CsPbBr3 upon light irradiation as revealed by in-situ X-ray photoelectron spectroscopy analysis, suggesting the formation of an S-scheme heterojunction in the TiO2/CsPbBr3 nanohybrids which greatly promotes the separation of electron-hole pairs to foster efficient CO2 photoreduction. The hybrid nanofibers unveil a higher CO2-reduction rate (9.02 μmol g–1 h–1) comparing with pristine TiO2 nanofibers (4.68 μmol g–1 h–1). Isotope (13CO2) tracer results confirm that the reduction products originate from CO2 source.

Graphitic carbon nitrides and their composites with various morphologies and bandgaps engineered for the hydrogen evolution reaction under visible light are reviewed. Semiconductor polymeric graphitic carbon nitride (g-C 3 N 4 ) photocatalysts have attracted dramatically growing attention in the field of the visible-light-induced hydrogen evolution reaction (HER) because of their facile synthesis, easy functionalization, attractive electronic band structure, high physicochemical stability and photocatalytic activity. This review article presents a panorama of the latest advancements in the rational design and development of g-C 3 N 4 and g-C 3 N 4 -based composite photocatalysts for HER application. Concretely, the review starts with the development history, synthetic strategy, electronic structure and physicochemical characteristics of g-C 3 N 4 materials, followed by the rational design and engineering of various nanostructured g-C 3 N 4 ( e.g. thinner, highly crystalline, doped, and porous g-C 3 N 4 ) photocatalysts for HER application. Then a series of highly efficient g-C 3 N 4 ( e.g. , metal/g-C 3 N 4 , semiconductor/g-C 3 N 4 , metal organic framework/g-C 3 N 4 , carbon/g-C 3 N 4 , conducting polymer/g-C 3 N 4 , sensitizer/g-C 3 N 4 ) composite photocatalysts are exemplified. Lastly, this review provides a comprehensive summary and outlook on the major challenges, opportunities, and inspiring perspectives for future research in this hot area on the basis of pioneering works. It is believed that the emerging g-C 3 N 4 -based photocatalysts will act as the “holy grail” for highly efficient photocatalytic HER under visible-light irradiation.