Enhanced waste water purification performance of solar-driven interfacial water evaporation through the integration of electrocatalysis

Abstract

Solar-driven interfacial water evaporation (SDIWE) has been proven to be an effective method for purifying polluted water. However, the challenging issue of removing volatile organic compounds (VOCs) from wastewater is frequently encountered. In this study, the SDIWE-electrocatalysis coupling system is established by employing defective TiO2 as both photothermal and electrode materials, and significant enhancements are achieved in terms of water evaporation rate and distilled water quality. The application of voltage not only generates joule heat but also reduces water evaporation enthalpy, contributing to the improved water evaporation rate. Under solar irradiation of 1.0 kW·m−2, the water evaporation rate increases from 1.43 kg·m−2·h−1 at 0 V to 1.63 kg·m−2·h−1 at 2.0 V. With the utilization of Ti@R-TiO2 foam as the anode and Ti@TiO2 foam as the cathode, it becomes feasible to directly oxidize VOCs at the anode and electrocatalytically reduce O2 at the cathode. Consequently, the VOCs can be effectively eliminated from distilled water. Applying 2.0 V under 1.0 kW·m−2 with oxygen inlet, approximately 25 % removal efficiency was achieved through electrolysis-SDIWE coupling system. This study's approach combining electrolysis with SDIWE presents a promising avenue for advancing SDIWE technology in order to achieve efficient wastewater treatment.