Chemical technology news from across RSC Publishing.
Bacteria generate cleaner power and water
13 March 2009
Microbial fuel cells can store away carbon dioxide as well as produce electricity, according to an international team of scientists.
Sunlight drives carbon dioxide reduction at the cathode
Microbial fuel cells offer a clean and efficient way of producing energy because the microbes that power them can feed off almost any organic waste. Xia Huang and colleagues at Tsinghua University, Beijing, China, and Ghent University, Belgium, demonstrated that sunlight helps microbes use dissolved CO2 (bicarbonate) in wastewater to produce electricity.
Huang showed that when she inoculated a cathode with a mixture of aerobic and anaerobic bacteria and shone a light on it, the biocathode reduced bicarbonate, generating electricity and increasing bacterial growth (biomass). But in the dark, power generation decreased rapidly, indicating that light is needed to supply energy to the fuel cell.
- Ashley Franks, University of Massachusetts, Amherst, US
Frédéric Barrière, who studies microbial fuel cells at the University of Rennes 1, France, describes the work as exciting. 'This integration of microorganisms as biocatalysts at the cathode and anode predicts that the microbial fuel cell is sustainable, even if the reported power output is still too low for practical applications.'
Cao acknowledges that increasing the power output is desirable. 'Improving the power output can be done by decreasing ohmic resistance - the focus of research for the last five years - or, more challengingly, by investigating the mechanism of microbe-electrode interaction,' says Cao. 'If this mechanism can be figured out then both the microbial community and the biofilm structure can be optimised and the performance improved.'
Link to journal article
A completely anoxic microbial fuel cell using a photo-biocathode for cathodic carbon dioxide reduction
Xiaoxin Cao, Xia Huang, Peng Liang, Nico Boon, Mingzhi Fan, Lin Zhang and Xiaoyuan Zhang, Energy Environ. Sci., 2009, 2, 498
Also of interest
Japanese scientists have made a biofuel cell that produces enough power to run an mp3 player or a remote controlled car
A simple iron complex could pave the way for new oxygen reduction catalysts with potential uses in low-temperature fuel cells
Carbon nanotube scaffolds that can support bacterial cells could be used as electrodes in microbial fuel cells.