Adjusting the Anisotropy of 1D Sb₂Se₃ Nanostructures for Highly Efficient Photoelectrochemical Water Splitting

Sb 2 Se 3 has recently spurred great interest as a promising light‐absorbing material for solar energy conversion. Sb 2 Se 3 consists of 1D covalently linked nanoribbons stacked via van der Waals forces and its properties strongly depend on the crystallographic orientation. However, strategies for adjusting the anisotropy of 1D Sb 2 Se 3 nanostructures are rarely investigated. Here, a novel approach is presented to fabricate 1D Sb 2 Se 3 nanostructure arrays with different aspect ratios on conductive substrates by simply spin‐coating Sb‐Se solutions with different molar ratios of thioglycolic acid and ethanolamine. A relatively small proportion of thioglycolic acid induces the growth of short Sb 2 Se 3 nanorod arrays with preferred orientation, leading to fast carrier transport and enhanced photocurrent. After the deposition of TiO 2 and Pt, an appropriately oriented Sb 2 Se 3 nanostructure array exhibits a significantly enhanced photoelectrochemical performance; the photocurrent reaches 12.5 mA cm −2 at 0 V versus reversible hydrogen electrode under air mass 1.5 global illumination.