Microbial bioelectrochemical cells for hydrogen generation based on irradiated semiconductor photoelectrodes

In recent years, one of the most important challenges of the 21st century is to satisfy the ever-increasing world's energy demand. Many efforts are being undertaken to find alternative renewable energy sources, which ideally should outcompete fossil fuel use in all its aspects. In this respect, photo-assisted microbial bioelectrochemical cells (MBECs) in which the reduction of water to hydrogen takes place have been of considerable interest in recent years. Two categories of such systems have been investigated: MBECs with a semiconductor photocathode or photoanode, and hybrid systems, in which an MBEC cell with dark electrodes is coupled to an electrochemical photovoltaic cell. A common denominator of all these systems is the need of microorganisms at the anode, the action of which results in the generation of an electron flow by organic matter oxidation. The aim of this review is to describe the general working principles, with respect to both biochemical and electrochemical aspects, and the performance of various categories of hydrogen-generating photo-assisted MBECs.

Automated summary

In recent years, significant efforts have been made to find alternative renewable energy sources, with photo-assisted microbial bioelectrochemical cells (MBECs) garnering considerable interest as a potential technology for hydrogen generation. Two main categories, namely systems with a semiconductor photocathode or photoanode and hybrid systems coupling an MBEC cell with dark electrodes to an electrochemical photovoltaic cell, have been investigated. Microorganisms are required at the anode in all these systems to generate an electron flow through organic matter oxidation.