MoS2/C @ Polyurethane Composite Sponges for Synergistic High-Rate Solar Steaming and Mercury Removal

TL;DR

This paper presents a novel 3-D MoS2/C polyurethane sponge solar steamer that achieves high evaporation rates and effectively removes heavy metals like mercury, offering a sustainable solution for water purification.

Contribution

It introduces an innovative 3-D composite sponge with synergistic high-rate solar steaming and mercury removal capabilities, demonstrating a new approach in solar-driven water treatment.

Findings

Evaporation rate of 1.95 kg/m²/h at 1 sun.

Energy efficiency of 88%.

Mercury reduction from 200 ppb to 1 ppb.

Abstract

Solar steam generation, a sustainable water-purification technology, holds substantial promises in resolving the global issue of shortage of drinkable water. Here, we report the design, fabrication, and performance of an innovative three-dimensional (3-D) solar steamer, offering synergistic high-rate steaming and heavy metal removal functions. The device is made of synthesized carbon-molybdenum-disulfide microbeads electrostatically assembled on a 3-D polyurethane sponge. The mesoporous composite sponge also serves as a freestanding water reservoir that avoids one-side contact to bulk water, effectively suppressing the commonly observed parasitic heat loss, and offering a high energy efficiency of 88%. When being sculptured into a 3-D spoke-like structure, the composite sponge achieves one of the highest evaporation rates of 1.95 kg m-2 h-1 at 1 sun. The solar steamer is demonstrated for water treatment, i.e. decontamination of metal ions, disinfection, and reducing alkalinity and hardness of river water. Particularly, the strong mercury adsorption of MoS2 reduces Mercury from 200 to 1ppb, meeting the stringent standard set by the Environmental Protection Agency, which is the first demonstration of mercury-removal powered by solar energy. The unique design, fabrication, water-handling strategy, and mercury-removal function of this high-performance solar steamer could inspire new paradigms of water treatment technologies.