Fast Seawater Desalination Integrated with Electrochemical CO2 Reduction.

Abstract

Coupling desalination with electrocatalytic reactions is an emerging approach to simultaneously addressing freshwater scarcity and greenhouse gas emissions. However, the salt removal rate in such processes is slow, and the applicable water sources are often limited to those with high salt concentrations. Herein, we show high-performance electrocatalytic desalination by coupling with electrochemical CO2 reduction using a carbon catalyst. A ZIF-8-derived carbon catalyst embedded with Cu nanoparticles delivers a high Faradaic efficiency of 94.3% for CO production at 288 μmol cm-2 h-1. The efficient CO2 electroreduction generates high current densities, which drive fast salt ion transfer across ion exchange membranes. The integrated device enables one of the quickest salt removal rates of 1043.49 μg cm-2 min-1 among various desalination methods. Drinking water can be obtained with an ion removal rate of 99% when natural seawater is used as the water source.