A Continuous Gradient Chemical Reduction Strategy of Graphene Oxide for Highly Efficient Evaporation-Driven Electricity Generation.

Abstract

Spontaneously harvesting electricity through a water evaporation process is renewable and environmentally friendly, and provides a promising way for self-powered electronics. However, most of evaporation-driven generators are suffering from a limited power supply for practical use. Herein, a high-performance textile-based evaporation-driven electricity generator based on continuous gradient chemical reduced graphene oxide (CG-rGO@TEEG) is obtained by a continuous gradient chemical reduction strategy. The continuous gradient structure not only greatly enhances the ion concentration difference between the positive and negative electrodes but also significantly optimizes the electrical conductivity of the generator. As a result, the as-prepared CG-rGO@TEEG can generate a voltage of 0.44V and a considerable current of 590.1µA with an optimized power density of 0.55mW cm-3 when 50µL of NaCl solution is applied. Such scale-up CG-rGO@TEEGs can supply sufficient power to directly drive a commercial clock for more than 2h in ambient conditions. This work offers a novel approach for efficient clean energy harvesting based on water evaporation.