Three dimensional nickel foam carried sea urchin-like copper-cobalt-cerium cathode for enhanced tetracycline wastewater purification in photocatalytic fuel cell

Abstract

Photocatalytic fuel cells (PFCs) regarded as a potential sustainable technique, have been broadly reported. In this work, the carbon quantum dot-loaded TiO2 photoanode and sea urchin-like CuCoCe ternary metal oxide cathode materials are successfully synthesized and used to construct PFC systems for efficient tetracycline (TC) degradation (45 mg/L) and simultaneous electricity generation. The results demonstrate that the CQDs-modified TiO2 photoanode has improved absorption intensity in both the UV and visible regions, and the photocurrent density at 1.23 V vs RHE reached 1.31 mA cm−2, which is 1.3 times higher than that of the original TiO2 photoanode. The established PFC system achieves the highest removal ratio of 96.9 % for TC in 60 min with a maximum power density of 0.77 mW cm−2. The PFC system can operate efficiently over a wide pH range (3.0–9.0). Furthermore, quenching experiments and ESR spectra show that the main reactive oxygen species in the degradation process are •O2−, 1O2 and •OH. This study provides meaningful way to develop multiple metal oxides as cathode of PFC system for efficient organic pollutant degradation and energy recovery.