The simultaneous optimization of the bulk and surface characteristics of photoelectrodes is essential to maximize their photoelectrochemical (PEC) performance. We report a novel onepot hydrothermal synthesis of textured and surface-reconstructed BiVO4 photoanodes (ts-BVO), achieving significant improvements in PEC water splitting. By controlling precursor molarity and ethylene glycol (EG) addition, we developed a stepwise dual reaction (SDR) mechanism, which enables simultaneous bulk texture development and surface reconstruction. The optimized CoBi/ts-BVO photoanode exhibited a photocurrent density of 4.3 mA·cm-2 at 1.23 V vs. reversible hydrogen electrode (RHE) with a high Faradaic efficiency of 98% under one sun illumination. Compared with nontextured BiVO4, the charge transport efficiency increased from 8% to 70%, whereas the surface charge transfer efficiency improved from 9% to 85%. These results underscore the critical role of both bulk and surface engineering in enhancing PEC performance. Our findings offer a streamlined approach for improving the intrinsic properties of photoanodes in solar water splitting.
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT) (No. RS-2024-00335976). This work was also supported by the Korea Institute of Energy Technology Evaluation Planning (KETEP) from the Ministry of Trade, Industry, Energy (No. 20214000000680).
