Simultaneous removal of methylene blue and Cr(VI) in a dual-chamber photocatalytic microbial fuel cell with WO3/MoS2/FTO photocathode

Jiye Xin; Shishi Kong; Xiaoliang Zhang; Yujuan Yang; Xuan Wang

doi:10.1016/j.heliyon.2024.e29204

Simultaneous removal of methylene blue and Cr(VI) in a dual-chamber photocatalytic microbial fuel cell with WO₃/MoS₂/FTO photocathode

Heliyon. 2024 Apr 10;10(8):e29204. doi: 10.1016/j.heliyon.2024.e29204. eCollection 2024 Apr 30.

Authors

Jiye Xin¹, Shishi Kong¹, Xiaoliang Zhang¹, Yujuan Yang¹, Xuan Wang^{1

2}

Affiliations

¹ School of Ecology and Environment, Inner Mongolia University, 24 Zhaojun Road, Hohhot, Inner Mongolia, 010070, China.
² Key Laboratory of Environmental Pollution Control and Waste Recycling, Inner Mongolia Autonomous Region, 24 Zhaojun Road, Hohhot, Inner Mongolia, 010070, China.

Abstract

Carbon felt was used as the anode and WO₃/MoS₂/FTO (fluorine-doped tin oxide) was used as the photocathode in a photocatalytic microbial fuel cell (PMFC). The photoelectric performance of the WO₃/MoS₂/FTO photocathode and the removal efficiency of methylene blue (MB) and Cr(VI) mixed pollutants were systematically investigated in the cathode chamber. The results showed that after 12 h of light irradiation in the PMFC with WO₃/MoS₂/FTO as the photocathode, the removal rates of MB and Cr(VI) were 84.56 and 68.11 %, respectively, which were much higher than those using WO₃/FTO as a photocathode (55.57 % and 45.26 %, respectively). The corresponding maximum output power was 33.14 mW/m², which was 1.85 times that of the WO₃/FTO photocathode PMFC. These results can be attributed to the fact that WO₃ is an n-type semiconductor and MoS₂ is a p-type semiconductor. Analysis of trapping experiments showed that the composite of WO₃ and MoS₂ formed a Z-scheme heterojunction, which improved the separation efficiency of the photoelectric carriers and enhanced the pollutant removal efficiency of the photocathode. PMFCs are a new and environment-friendly technology for removing pollutants thereby providing an experimental basis for future engineering applications.

Keywords: Cr(VI); Methylene blue; Photocatalytic microbial fuel cell; WO3/MoS2/FTO photocathode; Z-scheme heterojunction.