Unassisted photocatalytic hydrogen peroxide fuel cell based on dual photoelectrodes with high performance and stability

The exploitation of renewable sources, such as solar light, is strategically attractive in the current global energy crisis scenario. However, solar technologies that use earth-abundant materials that can efficiently harvest sunlight still need to be investigated. In this regard, photocatalytic fuel cells (PFCs) with dual-photoelectrode design are promising technologies able to efficiently generate electricity and/or chemical energy from solar irradiation. Both electrodes can absorb sunlight in a typical dual-photoelectrode PFC design, theoretically improving cell absorption and performance. Unfortunately, in practice, a suitable combination of electrodes, electrolytes, and fuel is still challenging regarding dual-photoelectrode PFCs. Herein, we investigated a dual-photoelectrode H2O2 fuel cell using a BiVO4-based photoanode and a CuO-based photocathode under different electrolyte conditions. The results have shown that electrolyte choice plays a significant role in cell performance and stability. In acetate electrolyte, the cell has delivered a stable short circuit photocurrent density as high as 3.4 mA cm(-2), a power density of 0.26 mW cm(-2), and 0.48 V open-circuit potential. In such a way, this device can provide a high unassisted performance to convert sunlight using earth-abundant materials in both anode and cathode, and at the expense of carbon-free fuel. Therefore, these findings establish promising directions toward the practical application of cost-effective unbiased photoelectrochemical technologies. [GRAPHICS] .