Algae Biofilm on Indium Tin Oxide Electrode for Use in Biophotovoltaic Platforms
Algae are amongst the most photosynthetically efficient organisms harnessing solar energy for all its metabolic life-supporting activities. The solar energy is transformed into chemical energy in a normally wasteful process. In this study, this excess wasted energy may be directed towards electricity generation in a biophotovoltaic platform. This is a new approach in renewable energy production from algae. As an initial step, algal biofilms are established on indium tin oxide (ITO) anodes. Two microalgae, the unicellular Chlorella UMACC 313 and the filamentous Spirulina UMACC 159 were used to form biofilm on ITO anodes under three different treatments (T1: unmodified smooth surface , T2: modified surface etched with interval of 2.5 mm between lines and T3: modified surface etched with interval of 1 mm between lines). Results show significantly higher biofilm coverage on the etched anodes compared to the smooth ones. Anodes of T3 registered the highest biofilm coverage of 99.46% for Chlorella. For Spirulina, highest biofilm coverage (80.70%) was observed on T2 anodes. The increase in biofilm coverage successfully resulted in increase of photosynthetic efficiency for both strains. Spirulina registered the highest maximum relative electron transport rate at 153.507 μmol electrons m-2s-1 compared to Chlorella (140.796 μmol electrons m-2s-1). This was correlated to pigment content. Biofilms established on the ITO anodes and the resulting high rate of photosynthetic efficiency achieved in these experiments are expected to enable electrical energy production from biophotovoltaic platforms.
Huang Nay Ming, Saadah Abd Rahman and Woon Kai Lin
F. L. Ng et al., "Algae Biofilm on Indium Tin Oxide Electrode for Use in Biophotovoltaic Platforms", Advanced Materials Research, Vol. 895, pp. 116-121, 2014