Two kinds of porous magnetic ferrite nanowires containing manganese (MnFe₂O₄ and Mn doped Fe₃O₄) have been successfully synthesized by thermal decomposition of organometallic compounds, using nitrilotriacetic acid (NA) as a chelating agent to coordinate with various ratios of Fe(II) and Mn(II) ions. The resultant MnFe₂O₄ and Mn doped Fe₃O₄ nanostructures are superparamagnetic, and have magnetization saturation values of about 45.9 and 48.7 emu g⁻¹ for MnFe₂O₄ and Mn doped Fe₃O₄, respectively. The Brunauer–Emmett–Teller specific surface areas of the MnFe₂O₄ and Mn doped Fe₃O₄ are 37.8 and 45.4 m² g⁻¹, respectively. The as-prepared porous MnFe₂O₄ and Mn doped Fe₃O₄ nanowires exhibit excellent ability to remove heavy metal ions and organic pollutant in waste water. In addition, these porous magnetic ferrites may be useful in other fields such as biomedicine and Li-ion batteries.

Solar-driven steam generation is an emerging, attractive, and sustainable technology for potential seawater desalination and wastewater purification. Despite the tremendous progress to date, some technological gaps still remain such as the seemingly unavoidable salt accumulation on the solar absorbers and the generally costly and delicate nanostructures. Here, a cost-effective biomass-derived hydrogel with rationally architected sponge-like skeletons is fabricated through a facile and scalable foaming-polymerization strategy. With advantageous features of organic-polymer chains, inorganic-particles and hierarchical bubble templates, the constructed hydrogel exhibits well-interpenetrative channels and unique porous topography with excellent resilience, fast water-transfer and enhanced light-trapping performances, leading to an ultrahigh and long-term stable evaporation rate of 1.77 ± 0.05 kg m⁻² h⁻¹ at 1 sun illumination out of high-salinity seawater (25 wt%) over the entire 7 12 h cycles without deterioration. This promising performance outperforms all the pioneering reported low-cost carbon-based solar absorbers for high-salinity desalination. Importantly, the salt accumulation prefers to crystalize around the edges, spatially isolated from the steam generation surface, achieving complete separation between water and solute. This simple technology to turn “waste” biomass to efficient solar-driven evaporators is anticipated to offer new possibilities to continuously and economically produce pure water from seawater and solute recovery.