Performance and mechanism analysis of photocatalytic degradation of tetracycline by SiC/CdS composites

In view of the high cost and low efficiency of tetracycline oxidation treatment, SiC/CdS composites were synthesized and the degradation performance of SiC/CdS for tetracycline was studied. In addition, the effects of CdS with different mass ratios and pH values on tetracycline degradation performance and the degradation mechanism were discussed. It was demonstrated that the degradation effect of SiC/CdS composites was significantly higher than that of SiC. In particular, the SiC/CdS-0.5 composite had the best degradation effect, and 78% tetracycline could be degraded within 2 h. The degradation rate constant of SiC/CdS-0.5 was 0.00969 min(-1). The catalytic mechanism of SiC/CdS was evaluated by density functional calculations. In addition, the TPV relaxation curve and the free radical catalytic structure of the samples indicated that holes were the active species that played a key role in the degradation of tetracycline by SiC/CdS, while hydroxyl radicals OH and superoxide radicals played a supporting role. This work provides good guidance and reference for the manufacture of efficient tetracycline degradation catalysts.