Z-scheme g-C3N4-AQ-MoO3 photocatalyst with unique electron transfer channel and large reduction area for enhanced sunlight photocatalytic hydrogen production

Abstract The transfer rate of photo-generated electrons is a critical factor that determines the photocatalytic efficiency of Z-scheme photocatalytic systems. Here, a novel Z-scheme g-C3N4-AQ-MoO3 photocatalyst with anthraquinone (AQ) serving as an e– transfer channel for hydrogen production was proposed. Its enhanced photocatalytic activity is due to the accelerated transfer of e– in the form of charge inside AQ, which also suppresses the recombination of photo-generated e– and h+. In addition, the reduction area is significantly increased by the exfoliation of g-C3N4 into thin layers. Due to the synergistic effect of rapid e– transfer and large reduction area, Z-scheme g-C3N4-AQ-MoO3 has a high hydrogen production efficiency that can reach 2018 μmol/g with the presence of triethanolamine as a hole sacrificial agent after 180 min of simulated sunlight illumination. This work provides a new strategy to design and develop Z-scheme photocatalytic systems with excellent electron migration rates and high charge separation efficiency.