Study on highly efficient Z-scheme p-n heterojunction Fe3O4/N-Bi2MoO6: Synthesis, characterization and visible-light-excited photocatalytic activity

Abstract

A series of Fe3O4/N-Bi2MoO6 Z-scheme p-n heterojunction was rationally developed and effectively synthesized using a simple hydrothermal approach. The structure, composition, morphology, and optical characteristics of the synthesized photocatalysts were studied by XRD, FTIR, XPS, EDX-equipped FE-SEM, UV–Vis-DRS, PL, VSM, and EIS. The photocatalytic activities of the as-prepared photocatalysts were estimated by malachite green dye (MG) degradation under visible light illumination.. The greatest removal of MG was achieved using Fe3O4/N-Bi2MoO6 heterojunction with 0.6:1 wt ratio achieving 98.2 percent degradation efficiency against MG, and its kinetic constant was higher than that of Bi2MoO6. The improved activity was attributed to the N doping and the creation of Z-scheme p-n heterojunctions, which resulted in the creation of electric field leading to a more stable structure, a broader spectrum response range, and a decreased electron-hole pair recombination rate due to the. According to trapping experiments, the major active species in the process of MG photocatalytic degradation were h+and ·O2– species. Additionally, the possible enhanced Z-scheme heterojunction mechanism of electron transfer was proposed. Based on the present study and experimental observations, Fe3O4/N-Bi2MoO6 as a visible-light-driven photocatalyst; is suggested to be a promising candidate for the removal of dyes from wastewater.