Electricity generation from the interaction between water and carbon materials is a new approach in the pursuit of high-efficiency energy conversion. Here, we report that a water droplet dropping onto a piece of porous carbon film can spontaneously generate electricity under ambient conditions. Twelve 5-μL water droplets can generate a voltage up to 5.2 V and illuminate a liquid crystal display. The voltage can be controlled by modulating the direction of the droplet infiltration, the zeta potential of the porous carbon, and the ion concentration. The results demonstrate that a hydrophilic porous carbon film with water droplets may function as a cost-effective electricity generator for harvesting energy from natural resources.

通过水和碳材料之间的相互作用来发电是追求高效能量转换的一种新方法。在这里，我们报告说，水滴在一块多孔碳膜上可以在环境条件下自发发电。十二个5μL水滴可产生高达5.2 V的电压并照亮液晶显示器。可以通过调节液滴渗透的方向，多孔碳的ζ电势和离子浓度来控制电压。结果表明，带有水滴的亲水性多孔碳膜可以用作从自然资源中收集能量的具有成本效益的发电机。