Core-shell Ag2CrO4/N-GQDs@g-C3N4 composites with anti-photocorrosion performance for enhanced full-spectrum-light photocatalytic activities

Abstract

It is a challenge to develop highly efficient and stable photocatalysts to harvest solar spectrum as broad as possible. In this work, for the first time, a nitrogen-doped graphene quantum dots (N-GQDs) modified Ag2CrO4@g-C3N4 core-shell structured composite was fabricated to achieve full-spectrum response from UV to near-infrared (NIR) region. In the Ag2CrO4/N-GQDs@g-C3N4 composites, Ag2CrO4 and g-C3N4 can be excited by UV and visible light, and N-GQDs can absorb NIR light to emit visible light, which greatly enhances the utilization of solar light. Moreover, compared with the normal hybrid heterojunctions, the core-shell structure provides larger contact area between Ag2CrO4 and g-C3N4. The large contact area and highly conductive N-GQDs effectively promote the photoelectron transfer from Ag2CrO4 to g-C3N4, which not only restrains the charge combination, but also greatly inhibits the photocorrosion of Ag2CrO4. The cycle experimental results showed that the performance of AN@CN did not decrease even after eight cycles of usage, and the XRD and EIS results also confirmed the stable nature of AN@CN composites. As a result, the optimized composites exhibit excellent photocatalytic degradation of doxycycline under full-spectrum light, and the possible photocatalytic mechanism was proposed. This work provides guidance for the design of high efficient photocatalysts with full-spectrum response and excellent stability.