Tuning the optoelectronic properties and nanostructure of silicon photoelectrodes for enhancing solar fuel production

Abstract Due to its broadband optical absorption and advancement in wafer-based processing technology, silicon is extensively employed in photovoltaic devices. However, the application of silicon for photoelectrochemical reactions in its wafer/bulk form is limited and has consistently demonstrated inadequate photoelectrochemical performance. This Review offers a critical summary on light-induced H 2 production, CO 2 reduction, NH 3 formation via nitrate or N 2 reduction and biomass valorization using silicon nanostructures. In these photoelectrochemical applications, how nanostructuring of silicon and tuning its optoelectronic/surface properties impact the performance is emphasized. Elucidating such a comprehensive correlation offers key insights into harnessing the true potential of silicon as a photoelectrode towards solar fuel production. In addition, emerging opportunities and strategies in designing silicon nanostructures-based photoelectrodes for light-driven single-atom catalysis and overall water splitting reactions are provided.