Performance evaluation of a novel visible-driven CNT/TiO2/WO3/CdS heterojunction in photocatalytic fuel cell: Photodegradation of Reactive Blue 19 and electricity production

Abstract

A photoelectrochemical degradation of reactive blue 19 (RB19) and electricity generation was modeled and optimized in a photocatalytic fuel cell with CNT/TiO2/WO3/CdS/FTO photoanode and Cu2S/FTO photocathode using response surface methodology-central composite design. The coated photocatalyst on fluorine-doped tin oxide (FTO) was characterized by surface and cross-section FESEM, EDX spectrum, EDS mapping, XRD, and DRS analysis. The CNT/TiO2/WO3/CdS and Cu2S were coated on FTO glass by applying the dip coating and combined dip coating-SILAR method, respectively. The efficiency of RB19 and Chemical oxygen demand removal under the optimum circumstances of 15 mg/L dye concentration, pH = 4, and the light intensity of 890 lm were obtained at 99.9 % and 70 % after 4.5 h, respectively. Moreover, the generated current density during the photocatalytic process was calculated at about 41.3 µA/cm2 after 90 min. The effect of air injection, open and closed electrical circuits, light radiation, and adsorption rate of photocatalysts on RB19 removal was examined. The five times reusability confirmed the good stability and photoactivity of coated catalyst on the FTO electrodes at the optimum conditions. The result indicated that the photocatalytic fuel cell is an excellent technology not only for wastewater treatment but also for energy production. © 2023 The Society of Powder Technology Japan