Experimental and numerical study of photocatalysis in Taylor photoreactors with carbon-quantum-dots/BiOCl as catalysts

A comprehensive CFD model considering the photo radiation, discrete phase dispersion, flow behaviors and photoreactions was built for Taylor-Couette reactors (TCRs). The carbon quantum dots (CQDs) modified BiOCl composites which were responsive to visible light were synthesized and used as the catalysts for photodegradation of organic pollutants. The degradation kinetic parameters were obtained experimentally. The validated model was used to investigate the effects of the key parameters of TCRs such as rotation speed, light intensity and catalyst properties. The interactions among the photo radiation field, catalyst distribution, flow field, and degradation efficiency were discussed. The results showed the addition of 8 cot % CQDs/BiOCl enhanced the degradation efficiency to 97% as compared to pure BiOCl, while the catalyst dosage had a limited impact on degradation performance. This work provides engineering insights in the CQDs-based photocatalysis, and the proposed model can serve as an effective tool for the design and scale-up of the TCRs.