Electricity generation from moss with light-driven microbial fuel cells

Fossil fuel depletion, increasing energy demands and concerns on greenhouse gas emissions heavily stress the search for sustainable and green energy alternatives. Plant microbial fuel cells (PMFCs) are an attractive carbon-neutral energy conversion technology that can generate useful electricity from microorganisms naturally present in soil and from the organic matter produced by plants during photosynthesis. We report an innovative membrane-less light-driven PMFC and demonstrate its ability to harvest energy from moss. The PMFC implements a CuO-Cu2O photocatalyst at the cathode, leading to a peak power output approximately 14 times higher than the case of no photocatalyst and a reduction in the Ohmic losses of approximately 50%. A light/dark cycle trend is observed, which help distinguish between the anodic and the photocatalytic contribution to the overall current generated. The use of a protective layer to prevent the photocatalyst leaching is also tested. The simplicity and cost-effectiveness of the design proposed overcomes the cost limitations of other PMFCs previously reported, thus facilitating their future scale up.