LAUSR

Clean energy infrastructures of the future depend on efficient, low‐cost, long‐lasting systems for the conversion and storage of solar energy. This is currently limited by the durability and economic viability of today's solar energy systems. These limitations arise from a variety of technical challenges; primarily, a need remains for the development of stable solar absorber–catalyst interfaces and improved understanding of their mechanisms. Although thin film oxides formed via atomic layer deposition have been widely employed between the solar absorber–catalyst interfaces to improve the stability of photoelectrochemical devices, few stabilization strategies have focused on improving the intrinsic durability of the semiconductor. Here, a sinuous black silicon photocathode (s‐bSi) with intrinsically improved stability owing to the twisted nanostructure is demonstrated. Unlike columnar black silicon with rapidly decaying photocurrent density, s‐bSi shows profound stability in strong acid, neutral, and harsh alkaline conditions during a 24‐h electrolysis. Furthermore, scanning transmission electron microscopy studies prior to and post electrolysis demonstrate limited silicon oxide growth inside the walls of s‐bSi. To the authors’ knowledge, this is the first time structure‐induced stability has been reported for enhancing the stability of a photoelectrode/catalyst interface for solar energy conversion.