Copper Nanoparticle Doped Reduced Graphene Oxide (CuNP@rGO) Coated Poplar Wood for Solar-driven Interfacial Desalination of Saline Water

Abstract

Global freshwater scarcity is one of the most pressing problems of the modern society. Solar driven interfacial desalination technology, which concentrates heat at the air-water interface and decreases thermal losses has gained an increasing attention owing to its high photothermal conversion efficiency and transformative environmental applications. However, there are still challenges of producing efficient and scalable photothermal materials with high evaporation rate, photothermal conversion efficiency and low cost. Graphene and its derivatives are ideal photothermal materials owing to their stability, excellent thermal and electrical conductivity, efficient broadband light absorption potential, lightweight and low cost. Conversion of graphene to reduced graphene oxide /plasmonic hybrid nanocomposites increases its performance and photothermal conversion efficiency. In the currents study copper nanoparticle doped reduced graphene oxide (CuNP@rGO) layered 3D poplar wood based interfacial desalination system was setup by depositing CuNP@rGO photothermal layer on porous hydrophilic poplar wood substrate and used for interfacial desalination of hypersaline water. The photothermal material displayed strong broadband solar absorption of ~95%, high evaporation rate of 1.39 kg.m-2.h-1, corresponding to photothermal conversion efficiency of ~96%, under 1-Sun solar irradiation, demonstrating the high energy efficiency and water generation potential. The results of the study demonstrated promising potential of the cost effective, environmentally sound, and scalable photothermal material for large scale real world saline water desalination and brackish water purification applications.