Electricity generation in fuel cell with light and without light and decomposition of tetracycline hydrochloride using g-C3N4/Fe0(1%)/TiO2 anode and WO3 cathode

Visible-light-driven photocatalytic Fuel Cell (PFC) is of great interest in the environmental pollutant remediation with energy recovering. Herein, enhancement in photocatalytic degradation of Tetracycline Hydrochloride (TC) with electricity generation was achieved in a single reactor of PFC with paired stainless-steel mesh electrode loaded with anodic g-C 3 N 4 /Fe 0 (1%)/TiO 2 and cathodic WO 3 catalyst (at various pH, 0.05 M Na 2 SO 4 , 10 Ω external resistance) with visible light and without light. With light, TC molecules were successfully removed (97.3% in 90 min, at initial and optimal pH 5), while generating 0.98 V cell voltage and 24 W m −2 power density, simultaneous removal of COD (chemical oxygen demand) and TOC (total organic carbon) was 91.3% and 95%, respectively, suggesting superior mineralization that can be explained by the excitation of the anodic triple component g-C 3 N 4 /Fe 0 (1%)/TiO 2. In contrast, without light, the removal of COD, TOC and the cell voltage were much lower (48.8%, 65.3%, 0.78 V). In dark, the fuel cell is self-driven and self-biased, forming potential gradient and degrading pollutants. The effects of solution pH, initial TC concentration on degradation and power generation were evaluated. This PFC degrading TC can maintain high photocatalytic activity and high power output capacity after 5 cycles with light. Without light, the electricity generation capacity was 50–70% that in visible light PFC. These features reveal that fuel cell with g-C 3 N 4 /Fe 0 (1%)/TiO 2 photo anode and WO 3 photocathode has great application potential for removing refractory pollutants from wastewater.