Facile one-step synthesis of a WO3/ZnWO4 heterojunction modified using ZnFe LDH enhances the PEC water splitting efficiency†

Photoelectrochemical water splitting represents a promising approach for directly converting solar energy into green hydrogen, offering a potential solution to the challenges of energy shortages and environmental pollution. In this work, a WO₃/ZnWO₄ binary heterojunction was synthesised by a simple and effective one-step drop casting method to enhance the charge separation efficiency; ZnFe LDH was deposited on the surface of the heterojunction with the aim of accelerating water oxidation and synergising with the heterojunction to enhance the photoelectrochemical performance of the photoanode. The photocurrent density of the WO₃/ZnWO₄/ZnFe LDH electrode can reach 2.1 mA cm⁻² at 1.23 V (vs. RHE). This value is approximately 4 times greater than that observed for pure WO₃ (0.53 mA cm⁻²). The IPCE and ABPE were able to improve by 3.1 times and 6 times, respectively.