Salt-Resistant, Self-Floatable Fe2O4/Ppy Nanoparticles Decorated Wood Pulp Sponge for Solar-Driven Seawater Desalination

Abstract

Water scarcity has become a major global challenge in recent years needed to deal with urgently. Solar evaporation has emerged as a renewable energy source and a novel technique for clean water production and wastewater treatment. However, developing a high-performance, environment-friendly, and scalable solar evaporator remains a significant challenge. Herein, we developed a high-performance, self-floatable, environmentally friendly, and single-step manufacturing of a two-dimensional solar steam generator. The developed solar evaporator is composed of facile coating of Fe2O4@PPy nanoparticles (NPs) deposit on low-cost and commercially available super hydrophilic wood pulp sponge which offers a sustainable solution to the ever-growing issues of the energy and water crises. The as-prepared foam exhibits good wettability (zero contact angle), salt-resistance (3 g /180 minutes), low thermal conductivity (0.225 W m−1 K−1), and excellent light absorption of ∼95% due to the omnidirectional porous surface of Fe2O4@PPy NPs. The broadband solar absorption of Fe2O4@PPy solar evaporator is capable to transform into thermal energy (42.3 ˚C) and generate vapors (1.62 kg m-2 h-1) along with 93 % photothermal conversion efficiency under one sun (1 kW m-2). Furthermore, the presented prototype can be directly installed to purify various types of wastewaters with a high rejection ratio of heavy metal ions (nearly 100%). This simple fabrication process with renewable polymer resources and photothermal materials provides fundamental guidance and practical application value toward developing high-performance solar evaporation technologies for remote areas and individuals. Keywords: Fe2O4@PPy, solar steam generation, wood pulp, polypyrrole.