Preparation of Fe₂(MoO₄)₃/graphene/Ti nanocomposite electrode for visible-light photoelectrocatalytic degradation of organic pollutants

The massive emission of organic pollutants, specially organic dyes into water poses a serious threat to the environment and human health. Photoelectrocatalysis (PEC) has been regarded as an efficient, promising and green technology for organic pollution degradation and mineralization. Herein, Fe₂(MoO₄)₃/graphene/Ti nanocomposite was synthesized and applied as a superior photoanode in a visible-light PEC process for degradation and mineralization of an organic pollutant. First, the Fe₂(MoO₄)₃ was synthesized by the microemulsion-mediated method. Then, Fe₂(MoO₄)₃ and graphene particles were simultaneously immobilized on a titanium plate by the electrodeposition technique. The prepared electrode was characterized by XRD, DRS, FTIR and FESEM analyses. The ability of the nanocomposite was investigated in the Reactive Orange 29 (RO29) pollutant degradation by the PEC. The Taguchi method was used for the visible-light PEC experiments design. The efficiency of RO29 degradation was enhanced with increasing bias potential, number of Fe₂(MoO₄)₃/graphene/Ti electrodes, visible-light power and Na₂SO₄ (electrolyte) concentration. The pH of the solution was the most influential variable in the visible-light PEC process. Furthermore, the performance of the visible-light PEC was compared with photolysis, sorption, visible-light photocatalysis and electrosorption processes. The obtained results confirm the synergistic effect of these processes on RO29 degradation by the visible-light PEC.