Synthesis of one-dimensional hierarchical Bi2O3 with enhanced photocatalytic reduction of Cr(VI) and degradation of organic compounds under simulated sunlight

Abstract

A one-dimensional (1D) hierarchical Bi2O3 is obtained by calcining hierarchical Bi2O2CO3. Hierarchical Bi2O3 exhibits good photocatalytic activity. Results show that 50 mg/L of Cr(VI) solution, 50 mg/L of tetracycline and 40 mg/L of biphenol A can be photodegraded in 10, 10 and 20 min under simulated sunlight with an apparent rate constant value of 0.331, 0.179 and 0.214 min−1, respectively. This enhanced photocatalytic performance is mainly ascribed to special hierarchical structure and the more negative CB position. Radical capture and EPR measurements all prove the superoxide (O2−) radical is the major active species for photocatalytic reaction. The transient photocurrent responses, PL emission and electrochemical impedance indicate 1D hierarchical Bi2O3 displays an improved separation efficiency of photogenerated e-h pairs. These findings would inspire many research for developing high-performance catalysts using under simulated sunlight.