Artificial photosynthetic approach steers hydrogen evolution with bismuth selenide nanoflakes decorated silicon nanowires

Abstract

Photoelectrochemical (PEC) water splitting offers a promising path toward green hydrogen production, but developing efficient photocatalysts remains a critical hurdle for large-scale adoption. In this study, we introduced a novel hybrid heterostructure for PEC water splitting, consisting of bismuth selenide (Bi2Se3) decorated silicon nanowires (Si NWs). This configuration achieved a high current density of 10.3 mA/cm2 at −1.2 V vs. RHE, along with an ABPE of 2.5 % at −0.8 V vs. RHE. Notably, these performance metrics surpass those of pristine Si NWs. The topological surface states in Bi-based layered chalcogenides, Bi2Se3 as cocatalysts with Si NWs, demonstrate robust charge transport which improves the conductivity of photoelectrodes in electrochemical reactions with high stability. Thus, the present study exploits the layered chalcogenides as an excellent cocatalyst for Si NWs that may lead to further advances in the hydrogen evolution reaction.