A highly [001]-textured Sb₂Se₃ photocathode for efficient photoelectrochemical water reduction

Anisotropic Sb₂Se₃ is an emerging earth-abundant photocathode for photoelectrochemical water splitting. However, controlling the growth of the Sb₂Se₃ film with optimal [001] crystallographic orientation is still the most challenging issue. Here, we successfully synthesized [001]-oriented Sb₂Se₃via a reliable and facile method. The [001]-oriented Sb₂Se₃ film could provide an excellent carrier-migration efficiency. Consequently, we achieved a record-high photocurrent density of −20.2 mA cm⁻² at 0 V_RHE and a very high half-cell solar-to-hydrogen efficiency of 1.36% under 1-sun simulated solar illumination in a TiO₂/[001]-Sb₂Se₃ photocathode. This work provides an effective strategy and important guidelines for rationally designing optoelectronic devices based on the [001]-oriented Sb₂Se₃ film.