Green energy from bug
doi:10.1038/nindia.2010.186 Published online 31 December 2010
Researchers have designed a new bio-fuel cell using carbon electrode, bacteria and an organic compound. The bio-fuel cell generates electricity without producing any harmful pollutants raising the prospect of a safe and alternative way to produce green energy.
Against the backdrop of global warming, bio-fuel cells emerge as eco-friendly and emission-free energy sources. Despite their good electrochemical properties, high costs prevent the use of platinum and gold electrodes.
For the design of bio-fuel cells, the researchers chose different carbon electrodes such as carbon paper, carbon cloth, and carbon felt. They used Escherichia coli bacteria. Platinum catalyst was loaded on the carbon cathode. E. coli cells in phosphate buffer solution and an organic compound as mediator were then injected into the anode compartment.
Carbon felt electrode exhibited higher current and power densities. Current density decreased for the carbon cloth electrode and further decreased for the carbon paper electrode. The carbon felt electrode having a substantially greater thickness than paper and cloth electrodes contributed to reduced electrical resistance and increased electron transportation.
The researchers also explored the role of an organic compound as a mediator to influence the power generation of the bio-fuel cells. They found that the organic compound efficiently transferred electrons from the microorganism to the electrode enhancing the power generation of bio-fuel cells.
The authors of this work are from: Specialized Graduate School of Hydrogen and Fuel Cell Engineering, Semi Conductor Research Center of Chonbuk National University, and School of Chemical Engineering and Technology, Chonbuk National University, Jeonju, Republic of Korea and Department of Physical Chemistry, School of Chemistry, Madurai Kamaraj University, Madurai, India.