A highly efficient NiFe-layer double hydroxide/TiO2 heterojunction photoanode-based high-performance bifunctional photocatalytic fuel cell

Abstract

A NiFe-LDH/TiO2 heterojunction photoanode is employed to improve photocatalytic degradation and electricity output of the dual-photoelectrode photocatalytic fuel cell (PFC) for the first time. Incorporation of NiFe-LDH can extend the optical response range, accelerate reaction kinetics, and enhance the electrocatalytic efficiency of the photoanode. The (NiFe)1:1-LDH/TiO2 photoanode possesses an extraordinary photocatalytic activity, and the photocurrent density achieved 1.85 mA cm-2 at 1.6 V vs. RHE with 1 M KOH solution, meanwhile, it was higher than over 1.5 times of the pure TiO2. Cuprous oxide is used as an ideal photocathode material in the PFC system. The photoelectricity conversion and photocatalysis degradation performance in degrading azo dye, glucose, and phenol as model organic waste have been entirely recorded under 1 sun illumination. The actual maximum power density of the proposed PFC was 0.206 mW cm-2 in degrading glucose over 150 min period. The azo dye removal of MB using the NiFe-LDH/TiO2 and pure TiO2 photoanode-based PFC was 94.6% and 80.5%, respectively. The prominent PFC activity shows that the proposed PFC could be used in organic wastewater treatment and energy conversion.