The construction and performance of photocatalytic-fuel-cell with Fe-MoS2/reduced graphene oxide@carbon fiber cloth and ZnFe2O4/Ag/Ag3VO4@carbon felt as photo electrodes

Abstract

Photo electrodes based on conductive carbon materials are prepared via hydrothermal loadings of Fe-MoS2/reduced graphene oxide (rGO, 300 W Xe) or ZnFe2O4/Ag/Ag3VO4 (9 W LED light). The photo electrodes are used in developing a promising and attractive photo-catalytic fuel cell (PFC) that can realize simultaneous pollutant degradation, power output and hydrogen generation. The photo electrodes were characterized using scanning electron microscope (SEM), X-ray Diffraction (XRD), X-ray photoelectron spectroscopy (XPS), ultraviolet-visible spectrophotometry (UV-Vis) and electrochemical analysis (LSV, CV, I-t). The degradation removal of Methyl orange (MO, 10 mg L−1) or berberine (BBR, 10 mg L−1) in a formic acid solution often used for hydrogen generation can reach ~98.2% and ~90.1% after 2 h irradiation in PFC, with a cell voltage of ~400 mV and hydrogen generation at ~0.025 μmol cm−2. Presence of formic acid promotes degradation of MO and BBR, while the presence of MO or BBR affects hydrogen generation adversely. The bias over the two photo electrodes drives the transfer of electrons from ZnFe2O4/Ag/Ag3VO4 to the Fe-MoS2/rGO and protons capture the electrons to form hydrogen. The holes and reactive oxidative species (ROS) oxidize the organics. This reduced the recombination of photo-induced carriers, thus improved the pollutant removal and hydrogen evolution.