CQDs modified Co-BiOCl nanosheets with improved effective light absorption and charge separation for photocatalytic CIP degradation and NOX removal

In this work, the Co-BiOCl/CQDs photocatalyst, with excellent degradation performance of ciprofloxacin and NOX, was synthesized by one-step hydrothermal method. By quantifying the effective light absorption (Iabs), charge separation efficiency (ηsep) and charge injection efficiency (ηinj) of the photocatalyst, it could be obtained that Co-doping could enhance the charge separation, and CQDs could improve the effective light absorption efficiency, while the charge injection efficiency of Co-BiOCl/CQDs was similar to that of BiOCl, demonstrating that Co and CQDs could not enhance the charge injection, and strongly demonstrating that the enhancement in effective light absorption and charge separation were main factors for improving photocatalytic activity. Moreover, the photocatalytic mechanism of CIP and NOx under visible light was also proposed. This work offered a new insight for the effect of Co and CQDs in the photocatalysts of Co-doping or CQDs based.