Synergistic High‐Rate Solar Steaming and Mercury Removal with MoS₂/C @ Polyurethane Composite Sponges

Abstract

Solar steam generation, a sustainable water‐purification technology, holds substantial promise in resolving the global issue of shortage of drinkable water. Here, the design, fabrication, and high‐performance of an innovative 3D solar steamer, offering synergistic high‐efficiency steaming and heavy metal removal functions are reported. The device is made of synthesized carbon‐molybdenum‐disulfide microbeads electrostatically assembled on a 3D 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 sculpted into a 3D 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 levels from 200 to 1 ppb, 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 can inspire new paradigms of water treatment technologies.

Biomass‐Derived Hybrid Hydrogel Evaporators for Cost‐Effective Solar Water Purification

“…Thus, the overall concentrations of heavy metal ions were reduced by six to nine orders of magnitude (ppb) after simultaneous one‐step adsorption and solar distillation (Figure 5f), which is comparable with current purification techniques . In addition, Hg 2+ is well‐recognized for its evaporative property that is different to remove by simple distillation process . From Figure 5d,f, the concentration of Hg 2+ was lowered by seven orders of magnitudes due to the adsorption function.…”

Portable Low‐Pressure Solar Steaming‐Collection Unisystem with Polypyrrole Origamis

“…Besides developing low‐cost photothermal materials, it is of paramount importance to design solar steaming‐collection systems that can be efficient as well as portable to address the needs of people on individual levels. 3D superstructures with large surface areas, which are often designed for energy and environment applications, have also demonstrated enhanced water evaporation rates due to the improved transpiration pathways compared to 2D structures . Some 3D solar steamers also exploit environmental energy and reach 100% efficiency in solar‐to‐vapor energy transfer .…”

“…In addition to the above study and analysis, the outstanding evaporation rates and energy conversion efficiency of the origami rose can also be understood from the perspective of operating temperatures of a solar steamer (Figure c,d). It has been observed that operating temperatures of 3D solar steamers are lower than those of their 2D counterparts . This can be attributed to the enlarged specific surface areas that allow more solar induced thermal energy to vaporize water, resulting in lower surface temperature.…”

Carbonized Tree‐Like Furry Magnolia Fruit‐Based Evaporator Replicating the Feat of Plant Transpiration

“…The solar evaporation rate is calculated to be 2.28 kg m −2 h −1 (Figure S9, Supporting Information). The performance of the 3D CMF was compared to the recently reported evaporators (Figure c) . Obviously, the 3D CMF shows excellent evaporation rates both in dark and under illumination.…”

“…The performance of the 3D CMF was compared to the recently reported evaporators (Figure 4c). [30][31][32][33][34][35] Global Challenges 2019, 3,1900040 Obviously, the 3D CMF shows excellent evaporation rates both in dark and under illumination. What's more, the evaporation rate shows no dependence on water quantity ( Figure S15, Supporting Information) and responses fast to the irradiation change ( Figure S16, Supporting Information).…”