Water-soluble volatile organic compounds (VOCs) are among the most difficult-to-treat species during wastewater treatment. The current purification and removal of high-concentration VOCs still rely on the energy-consuming distillation and high-pressure driven reverse osmosis technology. There is an urgent need for an advanced technology that can effectively remove high-concentration VOCs from water. Here, we report a metal–organic framework (MOF)/polyaniline (PANI) nanofiber array composite photothermal membrane for removal of high-concentration VOCs from water via molecular sieving during a solar-driven evaporation process. The modified zeolitic imidazole framework-8 (ZIF-8) layer grown on a PANI nanofiber array acts as a molecular sieving layer to evaporate water but intercept VOCs. The composite membrane exhibits high VOCs rejection and a high-water evaporation rate for water containing different concentrations of VOCs. When treating water containing VOCs with a concentration of up to 400 mg L–1, the VOCs rejection rate is up to 99% and the water evaporation rate is 1.0 kg m–2 h–1 under 1 sun irradiation (1 kW m–2). Our work effectively combines the molecular sieve effect with a solar-driven evaporation process, which provides an effective strategy for the treatment of water containing VOCs.

Water-soluble volatile organic compounds (VOCs) widely exist in wastewater and are among the most difficult-to-treat contaminants. Purification and removal of VOCs rely on energy-intensive technologies like distillation, reverse osmosis, or...

The employing of a microporous layer (MPL) with an appropriate pore size distribution and hydrophobicity between the carbon paper substrate and catalyst layer of proton exchange membrane fuel cells (PEMFCs) plays a decisive role in the management of gas transport and the crucial prevention of water flooding. However, enhancing the performance of PEMFCs by directly altering the structure of MPL has rarely been reported. The present work addresses this issue by fabricating hierarchical porous carbon (HPC) enabled MPLs via a dual template method employing zinc oxide and sodium chloride, and a silane-coupling agent is chemically grafted to HPC components of the MPL to improve water drainage instead of applying a conventional hydrophobic treatment. The physical and electrochemical properties of gas diffusion layers formed with different MPLs are analyzed, and the results indicate that the proposed MPL with excellent water drainage and efficient gas transport capability facilitates a higher output power density (863.62 mW cm–2) and lower mass transport impedance superior to a conventional MPL. This work provides a generic and feasible structure design for the development of MPLs that significantly improves the performance of PEMFCs.

The demand for lithium extraction from salt-lake brines is increasing to address the global lithium supply shortage. Nanofiltration membrane-based separation technology with high Mg2+/Li+ separation efficiency has shown great potential for lithium extraction. However, it usually requires diluting the brine with a large quantity of freshwater in the pre-treatment stage and only yields Li+-enriched solution. Inspired by the process of selective water/ion uptake and salt secretion in mangroves, we report here the direct extraction of lithium chloride (LiCl) powder from salt-lake brines by utilizing the synergistic effect of ion separation membrane and solar-driven evaporator. The ion separation membrane-based solar evaporator is a sandwich structure consisting of an upper photothermal layer to evaporate water, a hydrophilic macroporous membrane in the middle to generate capillary pressure as the driving force for water transport, and an ultrathin ion separation membrane at the bottom to allow Li+ to pass through and block other multivalent ions. This process exhibits outstanding lithium extraction capability. LiCl powder with a purity of 94.2% can be directly collected on the surface of the evaporator. When treating simulated salt-lake brine with ion concentration as high as 348.4 g L− 1, the Mg2+/Li+ ratio is reduced by 66 times (from 19.8 to 0.3). This research combines ion separation with solar-driven evaporation to directly obtain LiCl powder, providing a new and efficient approach for lithium extraction.