Construction of S-scheme heterojunction via coating ZIF-8-derived ZnCdS on NiP hydrangea for efficient photocatalytic hydrogen evolution coupled with benzyl alcohol oxidation.

Coupling light-driven hydrogen (H) evolution with benzyl alcohol (BA) oxidation is regard as a prospective strategy for obtaining value-added fuels as well as chemicals to deal with energy and environment crisis. In this contribution, a series of dual-functional noble metal-free S-scheme heterojunctions (ZnCdS@yNiP) with spatially separated and precise redox sites were constructed by synthesizing ZnCdS with regular morphology uniformly coated on NiP nanosheets via the template method for coupling H evolution with BA oxidation. The optimized ZnCdS@15 %NiP photocatalytic produced H (40.33 mmol g h) and benzaldehyde (BAD) (43.38 mmol g h), remarkably exceeding pure NiP and ZnCdS. Notably, the ZnCdS@15 %NiP gave a significant advantage in coupling H evolution and BA oxidation performance than the catalysts reported previously. The S-scheme heterojunction constructed between ZnCdS and NiP was demonstrated by Density functional theory (DFT) calculations, in-situ radiation X-ray photoelectron spectroscopy (XPS), Kelvin probe force microscope (KPFM) and electron paramagnetic resonance (EPR). The effect of S-scheme heterointerfaces and internal electric field promoted photo-induced charge separation and transfer efficiency, greatly enhancing the photocatalysis performance. This work emphasizes the significance of rational engineering of heterojunctions, providing an enlightening guidance on synthesis of dual-functional photo-redox catalysts to improve economical solar fuel exploitation and production of value-added chemicals.