Hollow core–shell Co9S8@In2S3 nanotube heterojunctions toward optimized photothermal–photocatalytic performance

Abstract

Reasonable design of advanced semiconductor photocatalyst structures is an effective strategy for solar-to-chemical energy conversion. Herein, hollow core–shell Co₉S₈@In₂S₃ nanotube heterojunctions are designed through two-step hydrothermal and solvothermal strategies. The construction of the heterojunction between Co₉S₈ and In₂S₃ enhances the separation efficiency of electron–hole pairs, and the hollow structure of Co₉S₈@In₂S₃ improves the scattering and refraction efficiency of incident light and the core–shell structure increases the contact area and provides adequate surface-active sites. In addition, the broad-spectrum absorption enables Co₉S₈@In₂S₃ to possess a satisfactory photothermal conversion ability, which can promote the photocatalytic hydrogen production obviously by increasing the system temperature. The maximum photocatalytic H₂ productivity achieved on the 20%Co₉S₈@In₂S₃ heterojunction is up to 4072.0 μmol g⁻¹ h⁻¹ without any noble metal as co-catalysts, which is 11.7 times higher than that of pristine In₂S₃ due to the efficient fabrication of the hollow core–shell heterojunction.