The g-C3N4 decorated carbon aerogel with integrated solar steam generation and photocatalysis for effective desalination and water purification

Abstract

Although solar steam generation (SSG) technology has shown promising advantages in the desalination of seawater, the treatment of organic pollutants in wastewater using SSG technology remains a challenge. Furthermore, the efficacy of evaporation materials is often hindered by the presence of organic pollutants, thereby limiting their practical application in the desalination of high-salinity wastewater. To address this issue, a synergistic approach combining photoevaporation and photocatalysis has been proposed as a potential solution. In this study, a novel rGO/MWCNTs aerogel (GMA) modified by photocatalyst g-C3N4 was fabricated by hydrothermal synthesis in the integrated treatment of unconventional waters. At one solar radiation (1 kW·m−2), GMA achieved an evaporation rate of 2.07 kg·m−2·h−1 and a remarkable solar evaporation efficiency of 92.7 %. In addition, GMA demonstrated excellent desalination performance with over 98 % removal of waste metal ions from seawater and brackish water after desalination. First applied aerogel to the lithium chloride wastewater evaporation and concentration, achieving the concentration of lithium chloride wastewater from 700 mg/L to 5.18 g/L. Additionally, the coordinated photocatalysis of g-C3N4 and rGO resulted in catalytic degradation rates of RhB and TB up to 91.6 % and 87.9 %, respectively. This study provides a new idea for SSG technology in high-salinity wastewater treatment.