Excellent charge separation over NiCo2S4/CoTiO3 nanocomposites improved photocatalytic hydrogen production

Abstract

The rapid migration and separation of photoinduced carriers is a key factor influencing photocatalytic efficiency. Constructing an S-scheme heterojunction is a strategic technique to enhance the separation of photo-generated carriers and boost overall catalytic activity. Herein, a simple physical stirring technique was adopted to successfully fabricate a novel NiCo₂S₄/CoTiO₃ S-scheme heterojunction photocatalyst. Upon exposure to light, the NiCo₂S₄/CoTiO₃-10 specimen demonstrated an outstanding hydrogen evolution rate of 2037.76 µmol·g⁻¹·h⁻¹, exceeding twice the rate observed for the pristine NiCo₂S₄ (833.72 µmol·g⁻¹·h⁻¹). The experimental outcomes reveal that the incorporation of CoTiO₃ significantly enhances the charge separation and transfer within the system. Concurrently, the formation of the S-scheme mechanism facilitates the separation of carriers while maintaining high redox capabilities. This work introduces an innovative approach to forming S-scheme heterojunctions based on bimetallic sulfides, thereby offering new prospects for the efficient utilization of solar energy.