Abstract
Photocatalytic H-2 production and degradation of pollutants are promising strategies for energy conversion and environmental protection, where highly efficient photocatalysts are required. Herein, a novel type of Y, C, and O tridoped g-C3N4 bifunctional photocatalyst was prepared via a simple one-step low-cost thermal polymerization technique, which exhibits a significant enhancement in photocatalytic redox efficiency under visible light for H-2 production and degradation of pollutants compared to bulk g-C3N4. The optimized Y0.1/C/O tridoped g-C3N4 photocatalyst exhibits a remarkable H-2 evolution rate (HER = 2542.4 mu mol g(-1) h(-1)) which is 5 times higher than that of pristine g-C3N4 with a high apparent quantum yield of 6% at 420 nm, besides excellent degradation efficiencies for organic pollutants (similar to 100, 98.5 and 82.4% for mixed dyes, congo red, and methylene blue, respectively). The influence of Y3+ concentration on the photocatalytic performance and electronic structure of Y/C/O-CN was also investigated. The major reactive species involved in the photodegradation process were found to be superoxide (O-2(-)) radicals. Moreover, the experimental and computational results suggest that the enhanced photocatalytic performance is due to the synergistic effect of Y, C, and O tridoping, which can adjust the band structure of g-C3N4, reduce the bandgap, improve visible-light absorption, and accelerate charge separation. This study paves the way to fabricate extremely effective tridoped photocatalysts for efficiently evolving hydrogen under visible light and resolving future environmental pollution.