Carbon Quantum Dots Decorated Bi4O5I2 with Greatly Improved Visible-Light Photocatalytic Performance

Here we report the construction of carbon quantum dots (CQDs)/Bi4O5I2 photocatalyst with improved photocatalytic performance for methyl orange (MO) degradation under visible light. In particular, the CQDs/Bi4O5I2 samples synthesized with 2 wt.% CQDs achieved the best performance for the degradation of MO among all samples. This enhancement is ascribed to the optimized CQDs content, which causes the strong light adsorption and efficient electron separation of Bi4O5I2. According to the electron spin resonance measurement and quenching experiments, the O-center dot(2)- and h(+) were found to be the main active species during the photodegradation process. Moreover, a possible photocatalytic mechanism of CQDs/Bi4O5I2 towards MO degradation has been proposed.