New insights in light-assisted microbial fuel cells for wastewater treatment and power generation: A win-win cooperation

Environment and energy used to be recognized and managed separately, thereby the light-assisted microbial fuel cells (MFCs) are alternatives to address environmental pollution and energy crisis effectively and interdependently. With harvesting solar energy, those multiple variants of light-assisted MFCs exert superior performance in terms of wastewater treatment and simultaneous power generation, even functionalized bioelectro-fuels production in customized conditions. Those hybrid systems are attached with promising prospect but still co-exist with serious challenges, requiring prompt solutions. Herein, we introduce the main knowledge of light-assisted MFCs mechanisms for newcomers. Then several preponderant coupling systems, including photoelectrode MFCs, photoelectrocatalysis-MFC hybrids and photosynthetic MFCs, are critically reviewed from the fundamental to optimization and application on the basis of recent research advancements. The scale-up strategy is discussed as a focal consideration of economic assessment. Moreover, this review proposes the predominant challenges confronted by those configurations, and new insights with correspondingly tailored direction for prospective study. Hopefully, this review can serve as a map for what has been achieved to date and what may be promising tomorrow.