Three-Dimensional Graphene Matrix-Supported and Thylakoid Membrane-Based High-Performance Bioelectrochemical Solar Cell

A combination of thylakoid membranes (TMs) as photobiocatalysts with high-surface-area electroactive materials could hold great potential for sustainable “green” solar energy conversion. We have studied the orientated immobilization of TMs on high-surface-area graphene electrodes, which were fabricated by electroreduction of graphene oxide and simultaneous electrodeposition with further aminoaryl functionalization. We have achieved the highest performance to date under direct electron transfer conditions through a biocompatible “wiring” of TMs to graphene sheets. The photobiocurrent density generated by the optimized mediator-free TM-based bioanodes yielded up to 5.24 ± 0.50 μA cm –2 . The photobioelectrochemical cell integrating the photobioanode in combination with an oxygen reducing enzymatic biocathode delivered a maximum power output of 1.79 ± 0.19 μW cm –2 . Our approach ensures a simplified cell design, a greater load of photosynthetic units, a minimized overpotential loss, and an enhanced overall performance.