Controlled synthesis of β-Bi2O3/Bi2O2CO3 hollow microspheres with enhanced photocatalytic degradation of tetracycline under visible light

Well-dispersed beta-Bi2O3/Bi2O2CO3 hollow microspheres were successfully synthesized by calcination an inter -mediate product fabricated via a solvothermal method using N, N-dimethyl formamide (DMF) as reaction media and carbon nanospheres as sacrifice templates. The molar ratio of beta-Bi2O3 and Bi2O2CO3 in beta-Bi2O3/Bi2O2CO3 composites can be adjusted by controlling the roasting conditions, which will influence the utilization of sunlight and the photo-induced charge carrier separation and transfer of the composites constructed, thus affecting photocatalytic activity. Experimental and characterization results suggest that the formation of the special structure could be ascribed to the interdiffusion of BiO+ and carbon chain during solvothermal reaction. Control experiments confirmed that as-prepared beta-Bi2O3/Bi2O2CO3 composites possessed reliable photocatalytic activity and recycle stability for tetracycline degradation, achieving 95.34 % under Xe lamp irradiation for 60 min and without significant decrease after four cycles. Our findings provide another insight for the transformation of elemental bismuth into beta-Bi2O3, and open up a general route for the synthesis of Bi2O2CO3-based composite hollow microspheres for water pollution control.