Solar vapour generation (SVG) represents a promising technique for seawater desalination to alleviate the global water crisis and energy shortage. One of its main bottleneck problems is that the evaporation efficiency and stability are limited by salt crystallization under high-salinity brines. Herein, we demonstrate that the 3D porous melamine-foam (MF) wrapped by a type of self-assembling composite materials based on reduced polyoxometalates (i.e. heteropoly blue, HPB), oleic acid (OA) and polypyrrole (PPy) (labeled with MF@HPB-PPyn-OA) can serve as efficient and stable SVG material at high-salinity. Structural characterizations of MF@HPB-PPyn-OA indicate that both hydrophilic region of HPBs and hydrophobic region of OA co-exist on the surface of composite materials, optimizing the hydrophilic and hydrophobic interfaces of the SVG materials, and fully exerting its functionality for ultrahigh water-evaporation and anti-salt fouling. The optimal MF@HPB-PPy10-OA operates continuously and stably for over 100 h in 10 wt% brine. Furthermore, MF@HPB-PPy10-OA accomplishes complete salt-water separation of 10 wt% brine with 3.3 kg m-2 h-1 under 1-sun irradiation, yielding salt harvesting efficiency of 96.5%, which belongs to the record-high of high-salinity systems reported so far and reaches zero liquid discharge. Moreover, the low-cost of MF@HPB-PPy10-OA (2.56 $/m2) suggests its potential application in the practical SVG technique.

Transition metal-based nanomaterials exhibit promising potential as highly active and low-cost electrocatalyst for alkaline water splitting, which can be achieved via elaborating compositional modulation and structural manipulation. This, however, normally involves multiple or even complex synthetic procedures. Herein, we report a simple one-step sulfidation of FeMnZn multi–metal skeletons for the preparation of highly efficient electrocatalysts. The incorporation of Mn and Zn induced hierarchical nano/micro sheet–to–sheet supported on open porous skeleton (FeMnZn/Mn-FeS, FMZS2), which not only facilitates electron/ion transport but also expands the accessible surface. Meanwhile, the Mn is introduced to optimize the adsorption/desorption ability of intermediates on the S sites in FeS. The resultant effect leads to remarkable electrocatalytic performance with good durability. Notably, the optimized FMZS2 delivers a 20 mA cm–2 at low overpotential of 118 mV for HER and a 100 mA cm–2 at overpotential of 390 mV for OER, outperfoming Pt/C and IrO2 catalyst, respectively. Moreover, the assembled alkaline electrolyzer also has good overall water splitting capability, which is better than that of the noble metal ones.