4 research outputs found

    Willow Catkins-Derived Porous Carbon Membrane with Hydrophilic Property for Efficient Solar Steam Generation

    No full text
    Biomass wastes are abundant and common in our daily life, and they are cost-effective, promising, and renewable. Herein, collected willow catkins were used to prepare a hydrophilic biochar composite membrane, which was placed in a tree-like evaporation configuration to simulate a natural transpiration process. The strong light absorption (∼96%) of the biochar layer could harvest light and convert it into thermal energy, which then is used to heat the surrounding water pumped by a porous water channel via capillary action. A hydrophilic light-absorber layer remarkably increased the attachment sites of water molecules, thereby maximizing the use of thermal energy. At the same time, hierarchically porous structure and large specific surface area (∼1380 m2 g–1) supplied more available channels for rapid water vapor diffusion. The as-prepared composite membrane with a low-cost advantage realized a high evaporation rate (1.65 kg m–2 h–1) only under 1 sun illumination (1 kW m–2), which was improved by roughly 27% in comparison with the unmodified hydrophobic composite membrane. The tree-like evaporation configuration with excellent heat localization resulted in the evaporator achieving a high solar-to-vapor conversion efficiency of ∼90.5%. Besides, the composite membrane could remove 99.9% sodium ions from actual seawater and 99.5% heavy metal ions from simulated wastewater, and the long-term stable evaporation performance proved its potential in actual solar desalination. This work not only fabricated an efficient evaporator but also provided a strategy for reusing various natural wastes for water purification

    Willow Catkins-Derived Porous Carbon Membrane with Hydrophilic Property for Efficient Solar Steam Generation

    No full text
    Biomass wastes are abundant and common in our daily life, and they are cost-effective, promising, and renewable. Herein, collected willow catkins were used to prepare a hydrophilic biochar composite membrane, which was placed in a tree-like evaporation configuration to simulate a natural transpiration process. The strong light absorption (∼96%) of the biochar layer could harvest light and convert it into thermal energy, which then is used to heat the surrounding water pumped by a porous water channel via capillary action. A hydrophilic light-absorber layer remarkably increased the attachment sites of water molecules, thereby maximizing the use of thermal energy. At the same time, hierarchically porous structure and large specific surface area (∼1380 m2 g–1) supplied more available channels for rapid water vapor diffusion. The as-prepared composite membrane with a low-cost advantage realized a high evaporation rate (1.65 kg m–2 h–1) only under 1 sun illumination (1 kW m–2), which was improved by roughly 27% in comparison with the unmodified hydrophobic composite membrane. The tree-like evaporation configuration with excellent heat localization resulted in the evaporator achieving a high solar-to-vapor conversion efficiency of ∼90.5%. Besides, the composite membrane could remove 99.9% sodium ions from actual seawater and 99.5% heavy metal ions from simulated wastewater, and the long-term stable evaporation performance proved its potential in actual solar desalination. This work not only fabricated an efficient evaporator but also provided a strategy for reusing various natural wastes for water purification

    Solvothermal Synthesis of Uniform Covalent Organic Framework Microspheres Enabling High-Loading Palladium for Oxygen Reduction Reaction

    No full text
    Although the solvothermal synthesis has become a prevailing strategy for the preparation of diverse spherical covalent organic frameworks (COFs), synthesis of uniform COF microspheres has still been a grand challenge due to the uncontrollable kinetics. Herein, we introduced 2,4,6-trimethylbenzaldehyde (TBA) as a molecular regulator in the reaction system, where the size and uniformity of spherical COFs were controlled by dynamic reversibility of imine exchange between TBA and building units and depended on the addition amount, molecular structure, and synthesis temperature. The applicability of the synthetic strategy was demonstrated by varying different structural units. Moreover, imine linkages of COF microspheres function as active sites suitable for coordinating with Pd single atoms and atomic clusters to promote electron transfer and synergistically enhance electrocatalytic oxygen reduction reaction. This work addressed the problems of poor uniformity and untunable size of COF spheres previously faced by the solvothermal method, thereby providing guidance for the construction of spherical COF-based catalyst supports
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