Improved the visible light response range of fibrous silica bismuth for enhancing photoelectrochemical water-splitting activity

The wide consumption of fossil fuel has significantly accelerated the global warming and climate change, prompting widespread concern. In response to these challenges, considerable efforts have been made to explore alternative energy solutions. Among these, hydrogen energy stands out as a highly promising option ascribed to its environmental benefits, and high efficiency. One notable method for hydrogen production is semiconductor-assisted photoelectrochemical (PEC) water-splitting, which is both effective and environmentally sustainable. Bismuth oxide (Bi2O3) demonstrated a narrow bandgap, adequate band alignment, and low toxicity which favorable for PEC water-splitting. However, Bi2O3 photoanodes face limitations, including rapid charge carrier recombination, which leads to sluggish oxygen evolution reaction and inefficient charge transfer. In contrast, fibrous silica bismuth oxide (FSBi) photoanodes have shown superior performance, featuring a reduced bandgap that improves solar light absorption. The FSBi photoanode demonstrated a photocurrent density of 93.0 mA/cm2 at 1.23 VRHE, outperforming commercial Bi2O3 photoanodes, which reached 65.6 mA/cm2. This enhancement is attributed to FSBi’s unique structure and extended visible light absorption range. These findings underscore the potential of FSBi photoanodes in advancing sustainable PEC water-splitting technologies.