Bio-solar cells incorporating catalase for stabilization of thylakoid bioelectrodes during direct photoelectrocatalysis

Thylakoid membranes have been proposed for electrochemical solar energy conversion, but they have been plagued with short term instability. In this paper, thylakoid membranes extracted from Spinacia oleracea were physically adsorbed onto Toray paper electrodes with and without catalase, followed by entrapment in a vapor deposited silica matrix. The bioelectrodes were tested using voltammetry and amperometry and tested in a complete photobioelectrochemical cell. Upon subsequent polarization experiments, a significant decrease in the maximum current density from 1.53 ± 0.13 μAcm−2 to 0.75 ± 0.14 μAcm−2 was observed without catalase present. When catalase was included in the anode, this current decrease was not observed, showing the importance of catalase to scavenge reactive oxygen species produced by the thylakoids during photoelectrocatalysis.