Insight into the enhanced degradation mechanism of g-C3N4/g-C3N5 heterostructures through photocatalytic molecular oxygen activation in Van der Waals junction and excitation

Environment pollution caused by organics is a global issue, which have attracted much attention in sustainable development of the earth. Photocatalysis is regarded as one of efficient methods to handle this environmental problem. In this work, the g-C3N4/g-C3N5 heterostructures with strong van der Waals junction was proposed, and they showed good performance in removal of antibiotic and organic pollutants. More importantly, after further investigating the enhanced photocatalytic mechanism, PL spectra and photoelectrochemical experiment indicated that the fast charge separation could be attributed to van der Waals junctions and excitation effects between g-C3N4 nanosheets and g-C3N5 nanorods. Various of as-generated reactive oxygen species (ROS) was activated by these above factors in molecular oxygen activation process, which were confirmed by Electron Spin Resonance (ESR) and quenching experiments. Moreover, high photocatalytic stability of this as-prepared g-C3N4/g-C3N5 heterostructures was also presented. This work provides a light prospect in the photocatalyst design and the photocatalytic interface mechanism insight.