ABSTRACT
Environmental conservation and energy scarcity have become two core challenges with the ever-increasing advancement of industry, particularly chemical energy rich wastewater comprising refractory organics and pathogenic microbes. Here, a multifunctional photocatalytic fuel cell (PFC) was devised using NiFe2O4 nanoparticle-loaded on pine tree-like ZnO/Zn (NiFe2O4/ZnO/Zn) photoanode and CuO/Cu2O nanorods-loaded on Cu (CuO/Cu2O/Cu) cathode for extracting electricity upon wastewater treatment. When fed with Rhodamine B (RhB) dyestuff, the NiFe2O4/ZnO/Zn-PFC provided the maximum power density (Pmax) of 0.539 mW cm-2 upon visible light irradiation with an average RhB degradation of 85.2%, which were 2.8 and 2.7 times higher than ZnO/Zn, respectively. The remarkable enhanced NiFe2O4/ZnO/Zn-PFC performance was owing to the synergistic effect of pine tree-like structure and Z-scheme heterostructure. The pine tree-like with high surface area was not only for effective harnessing photon energies but also provided more directional routes for rapid segregation and transport of carriers and higher interface contacting areas with electrolyte. Through a series of systematic characterizations, the Z-scheme heterostructure mechanism of the system and organics degradation pathway were also speculated. Additionally, the performance of the NiFe2O4/ZnO/Zn-PFC in industry printing wastewater showed Pmax of 0.600 mW cm-2, which was considerably impressive as real wastewater was challenging to accomplish. The phytotoxicity outcome also manifested that the comprehensive toxicity of RhB was eradicated after PFC treatment. Lastly, the excellent recyclability and the pronounced bactericidal effect towards Escherichia coli and Staphylococcus aureus were other attributions which enabled the NiFe2O4/ZnO/Zn-PFC for possible practical application.