Investigation on electron transfer from spinach thylakoids to modified electrodes in a photosynthetic electrochemical cell

Abstract

The depleting fossil fuel supply results in attempts to shift the energy prospects toward renewable energy sources. Solar energy has been considered as an attractive alternative energy source as it is abundant, free, and clean. Specifically, electrons generated from the water splitting reaction driven by solar energy have gained interest. Several efforts to utilize solar energy and the water splitting reaction have led to the development of inorganic and organic catalysts that mimic the natural plant water splitting catalyst. Although synthetic catalysts are known to be relatively more stable, recent studies show that the yield is still considerably lower than the natural manganese center. The potential of natural water splitting photosynthetic catalysts and their application in electricity generation are yet to be fully investigated and exploited. Photosynthesis is a process in which water and carbon dioxide are converted into carbohydrate by using light as energy source. Water is split into electrons, hydrogen, and oxygen catalyzed by the manganese center embedded inside photosystem II (PSII). Some studies have shown that the generated electrons can be transferred directly or indirectly to an electrode resulting in photocurrent generation in photosynthetic electrochemical cell (PEC). In an attempt to obtain a high efficiency PEC design, understanding the electron transfer pathway becomes paramount in enhancing the PEC performance. In our study, we use isolatedthylakoids from spinach leaves as the biocatalyst.