Yb-substitution triggered BiVO4-Bi2O3 heterojunction electrode for photoelectrocatalytic degradation of organics

摘要

As a photocatalyst with visible light response, BiVO4 has been widely investigated for organic wastewater treatment. However, its catalytic activity is greatly restricted because the photogenerated electrons and holes would recombine easily. Herein, we took a Yb-substitution strategy to construct BiVO4-Bi2O3 heterojunction for improving spatial separation of photogenerated electrons and holes. XRD, XPS, FESEM, and TEM investigations demonstrated that Yb-substitution can change the structure of BiVO4 and trigger the formation of BiVO4-Bi2O3 heterojunction. The photoeletrocatalytic activity of the as-synthesized composites was verified by degradation of MB under simulated sunlight. More importantly, the photoeletrocatalytic activity of 0.04Yb-BiVO4-Bi2O3 composite was significantly improved, resulting from the successful construction of BiVO4-Bi2O3 heterointerfaces. Moreover, the 0.04Yb-BiVO4-Bi2O3 composite displayed the best the catalytic performance, and the degradation rate of MB under simulated sunlight irradiation and an applied bias voltage of 1.0 V can reach 83.2 % within 2 h.