Multifunctional carbon nanowebs for solar-driven desalination and water purification with integrated Photothermal, antibacterial, and adsorptive capabilities

Abstract

Harnessing solar energy for water vaporization offers a sustainable approach to address global freshwater scarcity. However, existing photothermal nanoweb systems often exhibit trade-offs between evaporation performance, contaminant removal, and resistance to microbial fouling, limiting their practical deployment. In this study, a multifunctional carbon nanoweb engineered via scalable electrospinning and carbonization demonstrates the simultaneous achievement of high solar-driven water evaporation, selective dye adsorption, and broad-spectrum antimicrobial activity. The nanoweb exhibits an outstanding methyl orange adsorption capacity of 1202.04 mg·g⁻¹, effectively localizing pollutants and maintaining stable vapor transport. Optimized photothermal conversion achieves a solar-to-vapor efficiency of 95.25 % with an evaporation rate of 1.58 kg·m⁻²·h⁻¹ under one-sun irradiation, enabling clean water production of 10.18 kg·m⁻²·day⁻¹ from dye-contaminated water (50 mg·L⁻¹) under outdoor conditions. Performance remains stable over extended operation with actual wastewater. Under saline conditions, the system facilitates effective desalination, yielding ion-free condensate while sustaining evaporation rates comparable to deionized water. In parallel, embedded metallic nanoparticles impart potent antimicrobial functionality, achieving inhibition efficiencies of 98.38 % against Escherichia coli and 97.38 % against Staphylococcus aureus through synergistic oxidative and contact-based mechanisms. The integration of high-efficiency evaporation, selective pollutant removal, and microbial resistance into a single solar-responsive nanoweb represents a distinctive advancement in photothermal water treatment platforms, offering scalable and multifunctional solutions for decentralized, off-grid clean water production.