Integrating solar-driven water splitting with benzyl alcohol oxidation on ZnIn2S4 with Ni–N channel

Photocatalytic H₂ production has been regarded as a charming strategy for harvesting solar energy to chemical energy yet remains a great challenge due to the weak light absorption in visible range, low charge transfer, and fast recombination of photogenerated carriers. Here, we integrate solar-driven water splitting with benzyl alcohol (BA) oxidation, a typical platform chemical from biomass, for producing H₂ and benzaldehyde (BAD) over ZnIn₂S₄ nanosheets doped with Ni and N (Ni-N/ZIS). Mechanism studies show that Ni-N/ZIS provides a fast charge channel (i.e., Ni–N) for separating photogenerated electrons and holes, as a result of significantly enhanced photocatalytic performance. Impressively, Ni-N/ZIS displays a H₂ productivity of 18.7 mmol g⁻¹ h⁻¹ with an apparent quantum yield (AQE) of 29.1% at 420 nm, which is 37.4, 10.6 and 2.8 times higher than that of pristine ZIS, N/ZIS and Ni/ZIS, surpassing all the reported noble metal-free catalysts. Besides, the productivity of BAD reaches 17.5 mmol g⁻¹ h⁻¹ under the irradiation of visible light (λ ⩾ 420 nm). This work integrates two significant processes (i.e., solar-driven water splitting with benzyl alcohol oxidation) for producing H₂ and BAD, respectively, which will contribute to alleviating the current energy and environmental crisis.