Asymmetrical electrode modified by metal oxide nanoparticles for power generation devices from water evaporation

Water evaporation-driven power generation has attracted wide attention in recent years due to its capability to obtain electricity from the natural water evaporation. However, low output power and difficulties in large-scale manufacturing are still changeable for further development. Here, we design an asymmetric electrode with the three-layer structure (carbon cloth/filter paper/copper plate) for an evaporation-driven generator. Mesoporous NiCo₂O₄ nanoparticles are loaded on the net-like structured carbon cloth to provide more ion exchange microchannels, which can promote water evaporation. As a result, the generator can output electricity at room temperature with a stable open circuit voltage of 200 mV for about 24 h. The output current density and the output power of the generator can reach 90 μA/cm² and 14 μW/cm², respectively. This research provides an effective strategy for sustainable energy harvesting based on the water evaporation device without the limitation of dimension.