Sodium alginate-integrated MXene sediment /Fe₃O₄ evaporator for salt-resistant and efficient continuous water...

Solar-driven interfacial evaporation (SDIE) has become a viable method to alleviate the freshwater crisis by effectively utilizing green and environmentally friendly solar energy, among other advantages. However，achieving cost-effectiveness, salt tolerance, and operational stability remains the primary challenge for evaporator technologies in large-scale seawater desalination. Herein, we fabricated a low-cost, salt-resistant, and highly efficient solar evaporator by encapsulating low-cost MXene sediment (MS) and Fe₃O₄ nanoparticles with the natural polysaccharide sodium alginate (SA) and loading them onto a melamine foam (MF) substrate via a simple immersion method. The resulting Fe₃O₄/SA/MS/MF (FSMM) evaporator enables continuous seawater purification. Owing to the framework and porosity of MF, the FSMM exhibits excellent hydrophilicity, salt resistance, and anti-shrinkage properties. Under one-sun illumination, the evaporation rate reaches 2.26 kg·m^-2·h^-1; even in 15 wt% NaCl solution, it still maintains a relatively high evaporation rate of 1.94 kg·m^-2·h^-1. Furthermore, FSMM can be employed in various environments, such as those containing dye wastewater and acid-base wastewater. Therefore, this work capitalizes on the low cost of MS and Fe₃O₄, as well as the hydrophilicity of SA, to propose a practical and feasible solution for addressing challenges such as salt accumulation encountered by evaporators.