Quantum effect and Mo-N surface bonding states of α-MoC1-x modified carbon nitride for boosting photocatalytic performance

Photocatalytic degradation of pharmaceuticals in the aquatic environment is considered a promising strategy to address water pollution. In this study, a novel photocatalyst was constructed by decorating g-C3N4 (CN) with alpha-MoC1-x quantum dots (alpha-MoC1-x-QDs) through a facile calcination method. The catalyst showed enhanced tetracycline (TC) degradation performance under visible light. The unique Mo-N surface bonding states and quantum effect leading to superior TC degradation activity (89.1%) compared to pure CN (21.8%) were reported and revealed. More importantly, the mechanism for the significant enhancement of photocatalytic activity of the catalyst was investigated by DFT (density functional theory) calculations and photo-electrochemistry measurements. The results confirmed that the effect of alpha-MoC1-x-QDs on CN improved the light absorption capacity obviously, and the Mo-N surface bonding states accelerated the charge migration from CN to alpha-MoC1-x-QDs. Moreover, the TC degradation pathway, intermediates and photogenerated carrier transfer behaviors were also discussed in depth. This research provides a new strategy for the construction of noble-metal-free co-catalyst/semiconductor composite materials in the photocatalytic degradation of antibiotics.

Automated summary

In this study, a novel photocatalyst was developed and demonstrated to enhance the degradation of tetracycline under visible light. The mechanism behind the improved photocatalytic activity was investigated and explained using experimental and computational methods.