In-situ zinc vanadate layer derived from highly hydrophilic substrate for PEC performance enhancement of Zn-doped BiVO₄ photoanode

Owing to serious concerns regarding environmental issues, extensive research is being conducted to develop eco-friendly and sustainable energy sources. One promising solution is the utilization of solar energy for energy production using photoelectrochemical (PEC) methods. However, the performance of photoanodes is frequently hindered by high recombination rates and inadequate charge transport. To address these issues, we designed an approach that incorporates an ultrathin hydrophilic carbon (UTHC) film on a substrate. The UTHC film enhanced the hydrophilicity of the FTO surface and enabled the synthesis of a zinc vanadate layer for efficient charge transfer. As a conductive bridge, the zinc vanadate layer promotes effective charge transfer for excellent PEC performance. The resulting carbon film/Zn-doped BiVO₄ (CZB) photoanode exhibited significantly improved PEC performance, achieving a remarkable photocurrent density of 1.515 mA∙cm⁻² and a separation efficiency of 9.58 % at 1.23 V_RHE. This study demonstrates a potential method for enhancing PEC performance for sustainable energy conversion using a highly hydrophilic metal oxide layer on an FTO substrate.