Acid-resistant bilayer MXene/attapulgite-g-C3N4/BiOBr aerogel for high-efficiency solar-driven interfacial evaporation and photocatalytic water treatment

Abstract

Solar-driven interfacial evaporation technology constitutes a significant advancement in addressing global water scarcity. However, its large-scale application is constrained by the persistent challenge of organic compound contamination in water sources. To surmount this limitation, the present study innovatively integrates photocatalytic degradation with solar interfacial evaporation via the development of a bifunctional material. Specifically, a dual-layer aerogel (MXene/PPAL-g-C₃N₄/BiOBr) incorporating a type-II g-C₃N₄/BiOBr heterojunction, polymer matrix, and MXene was designed and fabricated, featuring abundant porosity, excellent hydrophilicity, and low thermal conductivity. Capitalizing on these inherent advantages, the as-prepared aerogel exhibits superior evaporation performance in both pure water and simulated acidic wastewater. Under 1 kW m⁻² illumination, the material achieves an evaporation rate of 1.59 kg m⁻² h⁻¹ with an energy conversion efficiency of 97.1%. Notably, in 3% H₂SO₄ solution, the aerogel maintains a high evaporation rate of 1.50 kg m⁻² h⁻¹ over 1 h, accompanied by an energy conversion efficiency of 91.8%, thereby demonstrating good acid resistance. Additionally, the aerogel exhibits prominent visible-light photocatalytic activity, with the degradation rate of tetracycline reaching up to 91% after 80 min.