Amphiphilic engineering of MoS2–g–C3N4 nanocomposites into a mangrove-inspired cascade system for sustainable drinking water production

Abstract

Drinking water contamination and water shortages are seriously exacerbated by industrial wastewater discharge. However, due to the high complexity of wastewater treatment systems, effective high-concentration pollutant removal and simplified wastewater recycling remain major challenges. Inspired by mangrove interconnected purification mechanisms, a novel cascade water treatment system has been developed using MoS₂–g–C₃N₄ (MoG), an amphiphilic material, as the main and single component to directly produce drinking water from wastewater with high efficiency. This cascade system integrates membrane filtration and solar-powered water evaporation processes to produce clean water, while also overcoming the requirement for less polluted source water that is typically required for standalone solar evaporation-based clean water production. The MoG membrane, featuring an amphiphilic platform, exhibits a high removal rate for organic and heavy metal contaminants and achieves a water flow of 966 L m⁻² h⁻¹ bar⁻¹ and an 80% efficiency in pollutant removal. The MoG-based aerogel enables nano- and micro-channels and exhibits a clean water production rate of 1.48 kg m⁻² h⁻¹ under 1 sun irradiation. The compact cascade system for practical use can produce drinking water that meets WHO standards from heavily polluted wastewater with an average hourly water production rate of 1.39 kg m⁻² h⁻¹. Life cycle assessment confirms that the cascade system displays significant environmental profile improvement with reduced CO₂ equivalent (CO_2e) levels with only 1/25 of that observed in conventional water treatment systems.