Photo-assisted microbial fuel cell systems: critical review of scientific rationale and recent advances in system development

Abstract

Bioelectrochemical systems such as microbial fuel cells (MFCs) have gained extensive attention due to their abilities to simultaneously treat wastewater and generate renewable energy resources. Recently, to boost the system performance, the photoelectrode has been incorporated into MFCs for effectively exploiting the synergistic interaction between light and microorganisms, and the resultant device is known as photo-assisted microbial fuel cells (photo-MFCs). Combined with the metabolic reaction of organic compounds by microorganisms, photo-MFCs are capable of simultaneously converting both chemical energy and light energy into electricity. This article aims to systematically review the recent advances in photo-MFCs, including the introduction of specific photosynthetic microorganisms used in photo-MFCs followed by the discussion of the fundamentals and configurations of photo-MFCs. Moreover, the materials used for photoelectrodes and their fabrication approaches are also explored. This review has shown that the innovative strategy of utilizing photoelectrodes in photo-MFCs is promising and further studies are warranted to strengthen the system stability under long-term operation for advancing practical application.

Graphical Abstract

Highlights

• Integrating photoelectrodes in MFCs can enhance the power output and treatment efficiencies.

• Photosynthetic microorganisms contribute in converting light sources to electrons.

• Various types of semiconductor materials are used as photoelectrodes in MFCs.

• The stability and photocorrosion of photoanode under the long-term operation need further investigation.

Keywords:

• Photoelectrode
• photo-assisted bioelectrochemical system
• microbial fuel cell
• photosynthetic microorganisms
• electrospinning

Acknowledgment

T. N. D. Cao would like to thank the NTU Postdoctoral Fellowship supported by the “Higher Education Sprout Project,” National Taiwan University, Taiwan.

Disclosure statement

The authors report no conflict of interest.

Additional information

Funding

H.-Y. Hsu acknowledges financial support from the Research Grants Council of Hong Kong (grant no. 21203518 and F-CityU106/18), City University of Hong Kong (grant no. 7005289 and 9667213), Shenzhen Science Technology and Innovation Commission (grant no. R-IND12302). C.-P. Yu would like to thank the research funding from the Ministry of Science and Technology, Taiwan (grant nos. 109-2221-E-002-084-MY2, 108-2221-E-002-118-MY2).