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

Well-dispersed β-Bi2O3/Bi2O2CO3 hollow microspheres were successfully synthesized by calcination an intermediate 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 β-Bi2O3 and Bi2O2CO3 in β-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 β-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 β-Bi2O3, and open up a general route for the synthesis of Bi2O2CO3-based composite hollow microspheres for water pollution control. [Display omitted] •Series of β-Bi2O3/Bi2O2CO3 photocatalysts with hollow structure were successfully designed and constructed.•The structure-activity relationship between catalyst structure and properties were elucidated.•A possible formation mechanism for the special structure was proposed.•The heterojunctions present excellent activity and stability for photocatalytic TC removal efficiency.