Graphitic Carbon Nitride/ Zinc Oxide Heterostructure Photocatalyst for Azo Dye Removal and Electricity Generation Via Photocatalytic Fuel Cell

Abstract

Photoanode is a crucial part of the photocatalytic fuel cell (PFC) system for its function to degrade organic pollutants and produce electrons for electricity generation. A facile way was used to fabricate the heterojunction graphitic carbon nitride/zinc oxide (GCN/ZnO) composites through combustion of urea and zinc acetate dihydrate in three different mass ratios. The synthesised GCN/ZnO composites were then loaded on a carbon plate as photoanode by employing ultrasonication and immobilisation methods. The synthesised GCN/ZnO composites were characterised by using X-ray diffraction (XRD), Fourier-transformed infrared spectroscopy (FTIR), N2 sorption–desorption isotherms and scanning electron microscopy (SEM). The GCN/ZnO photoanode was applied in a PFC with platinum-loaded carbon paper as the cathode. Reactive Red 120 (RR120) was used as a model pollutant in the PFC under ultraviolet light (UVA) irradiation. The findings revealed that the GCN/ZnO2 heterojunction photoanode achieved a decolourisation efficiency of 55.24% in 10 mg/L of RR120, which was 0.9 times higher than that of the GCN photoanode, while the maximum power density was 17.14 mW/m2, which was 13.39 times compared with that of the GCN photoanode.