In situ construction of η-Fe2O3/g-C3N4 Z-scheme heterojunction on nickel foam with efficient interfacial charge transport for enhanced photodegradation of Rhodamine B

Abstract

The design of efficient, low cost and recyclable photocatalyst is of great significance for disposing organic wastewater. In this work, η-Fe2O3/g-C3N4 heterostructure was constructed by in-situ cyclic voltammetry codeposition and calcination on nickel foam (NF). The microstructural and morphological characterization of the sample confirmed that spherical η-Fe2O3/g-C3N4 nanocomposites were co-deposited on three-dimensional porous NF to form Fe2O3/g-C3N4/NF photoelectrode under 50 cycles of 50 mV/s electric field. The removal rate of as-prepared η-Fe2O3/g-C3N4/NF photoelectrode for 10 mg·L−1 Rhodamine B solution reaches 95.2 % in 1h, which is 5.6 times of g-C3N4/NF and 5.3 times of η-Fe2O3/NF, respectively. According to the electrochemical test results, the enhanced photocatalytic activity of η-Fe2O3/g-C3N4/NF was principally due to efficient photogenerated charge separation and transfer ability of the photoelectrode. The results of active species capture experiments indicate that superoxide radical, hydroxyl radical and hole almost equivalently participated in photodegradation of η-Fe2O3/g-C3N4/NF, and its possible photodegradation mechanism was proposed on the basis of Z-scheme charge transport path. The η-Fe2O3/g-C3N4/NF nanocomposites would be expected to become a promising photoelectrode for large-scale applications.