Boosting Unassisted Alkaline Solar Water Splitting Using Silicon Photocathode with TiO2 Nanorods Decorated by Edge‐Rich MoS2 Nanoplates

Abstract To construct a highly efficient photoelectrochemical tandem device with silicon photocathode operating in alkaline conditions, it is desirable to develop stable and active catalysts which enable the photocathode to reliably perform under an alkaline environment. With nanostructured passivation layer and edge‐exposed transition metal disulfides, silicon photocathode provides new opportunities for achieving unbiased alkaline solar water splitting. Here, the TiO2 nanorod arrays decorated by edge‐rich MoS2 nanoplates are elaborately synthesized and deposited on p‐Si. The vertically aligned TiO2 nanorods fully stabilize the Si surface and improve anti‐reflectance. Moreover, MoS2 nanoplates with exposed edge sites provide catalytically active regions resulting in the kinetically favored hydrogen evolution under an alkaline environment. Interfacial energy band bending between p‐Si and …