Mesoporous SiO2-derived g-C3N4@CdS core-shell heteronanostructure for efficient and stable photocatalytic H-2 production

摘要

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 H-2 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 H-2 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.