Mesoporous SiO2-derived g-C3N4@CdS core-shell heteronanostructure for efficient and stable photocatalytic H2 production

Abstract

Semiconductor-based heteronanostructures with wide light absorption and efficient electron-hole separation properties exhibit great potential for photocatalytic applications. Here we employ the mesoporous SiO2 nanoparticles as the template to simultaneously exfoliate the nano-confined g-C3N4 and deposit the CdS nanoparticles to form a series of core-shell SiCN@CdS heteronanostructures for photocatalytic H2 production under the visible light irradiation. Based on the physicochemical characterizations, we have been able to discuss the compositions, structures, and properties of the core-shell photocatalysts. Benefiting from the optimized equilibrium state of a relative high specific surface area, light absorption, crystalline degree, and a homogeneous dispersion of the outer CdS nanoparticles, the SiCN@2CdS exhibits the highest photocatalytic activity and stability for H2 production under the visible light irradiation. Results also suggest that the existence of the SiO2 template is benefit to suppress the aggregation and improve the recyclability of the core-shell photocatalysts when they are applied in the aqueous phase. The present study suggests a new sight on the template-assisted designing and synthesizing high-reactive, low-cost, environmental-stable, and easy-recyclable photocatalysts by precisely controlling the microstructures.