Integration of Photosystem I with Graphene Oxide for Photocurrent Enhancement



Photosystem I is a photoactive membrane protein used in nature to photo-excite electrons with nearly unit internal quantum efficiency, sparking interest in using this biomaterial for solar energy conversion. Films of PSI deposited on p-doped silicon have previously demonstrated significant photocurrents with an electrochemical mediator; however, improvement in electron transfer is needed. Here, it is investigated how PSI can be combined with graphene oxide (GO) or reduced graphene oxide (RGO) to generate composite films capable of improved photoelectrochemical performance. It is found that both composite films outperformed the PSI film alone, and the PSI-GO composite film is found to perform the best. The enhancement is attributed to the decreased impedance and shift in the onset potential of the composite films.