A novel Z-scheme Bi4O5I2/NiFe2O4 heterojunction photocatalyst with reliable recyclability for Rhodamine B degradation

Construction of heterojunction with reusability is one of the effective ways to avoid secondary pollution and strengthen photocatalysis. Herein, a magnetically recyclable Z-scheme Bi4O5I2/NiFe2O4 heterojunction photocatalyst was successfully fabricated by a two-step hydrothermal method. Through adjusting the theoretical molar proportion of NiFe2O4 to Bi4O5I2, it was verified that the optimal composite could decompose 98.5% Rhodamine B (RhB, 10 mg/L) within 60 min under simulative sunlight and 98.1% RhB within 80 min under visible light. According to the characterizations, the superior performance was mainly associated with the small band gap energy (2.44 eV) and efficient separation of photo-generated electrons and holes caused by the formation of heterojunction. Meanwhile, the enlarged specific area (27.6 m(2)/g) provided many adsorptive sites and active sites to improve the reaction further. Moreover, the trapping experiment indicated that the photo-degradation involved center dot O-2(-), center dot OH and h(+). After confirming the reliable activity, reusability and stability of the photocatalyst, an inferred mechanism was shown. In summary, the design of this magnetically recyclable Z-scheme Bi4O5I2/NiFe2O4 heterojunction photocatalyst can become a new choice to purify wastewater. (C) 2021 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.

Automated summary

A magnetically recyclable Z-scheme Bi4O5I2/NiFe2O4 heterojunction photocatalyst was successfully fabricated, showing excellent degradation performance under simulated sunlight and visible light. The design provides a new choice for wastewater purification with reliable activity, reusability, and stability.