Plasmonic Ag@SiO_2 core/shell structure modified g-C_3N_4 with enhanced visible light photocatalytic activity

摘要

High rate of charge carrier recombination is a critical factor limiting the photocatalytic activity of g-C_3N_4. In this contribution, we demonstrate that this issue can be alleviated by constructing a plasmonic photocatalyst with tailored plasmonic-metal nanostructures, i.e., core-shell-typed Ag@SiO_2 nanoparticles. Compared with pure g-C_3N_4, the photocatalytic hydrogen production activity was enhanced by 63% for Ag@SiO_2/g-C_3N_4. As analysis from the photoluminescence results, the enhancement could be attributed to that plasmonic nanostructures favored the separation of electron-hole pairs in the semiconductor due to localized surface plasmons resonance effect. It was found that the silica shell between the Ag nanoparticles and g-C_3N_4 was essential for the better photocatalytic activity of Ag@SiO_2/g-C_3N_4 than that of Ag/g-C_3N_4 by limiting the energy-loss Foerster energy transfer process.