Resistance matching materials nanoarchitectonics for better performances in water evaporation-driven generators.

The improvement of electricity production for water evaporation-driven generators (WEGs) remains a challenge. Herein, two types of WEGs were designed to study the resistance matching for improving the electricity production. One type of reduced graphene oxide/carbon nanotube (RGO/CNT) WEG was constructed using RGO with adjustable resistances as working material and CNTs with fixed resistance as electrode material. The other type of graphene oxide (GO)/RGO WEG was constructed using RGO with adjustable resistance as electrode material and GO with fixed resistance was used as working material. The open circuit voltage of RGO/CNT increased from 15 to 56 mV and then decreased to 22 mV with increasing RGO resistance. The short circuit current of RGO/CNT also first increased and then decreased. The performance of GO/RGO was similar with that of RGO/CNT. Typically, the RGO/CNT and GO/RGO WEG showed the highest performance when the working material to electrode material resistance ratio was 2272 and 2365, respectively. It showed that the best resistance ratio of working material to electrode material was in the range of 2000-2500, which helped to improve about 2-5 times of electricity efficiency in the WEG. The present work provides a new direction for optimizing performance of WEGs.