The design and preparation of electrode materials with excellent performance is particularly important due to the current global scarcity of energy supplies, especially those using sustainable and renewable materials. In this work, it is first proposed to apply iron silicate (FeSi), which is synthesized using environmentally friendly biomass as a raw material, as an electrode material for supercapacitors (SCs). FeSi is derived from the calcination of reed leaves (RLs) in combination with a hydrothermal method, and spherical FeSi retains the porosity of the RL precursors and shows remarkable electrochemical performance. The specific capacitance of FeSi as a SC electrode can reach 575 F g−1 at 0.5 A g−1 in the voltage window from −1 to −0.5 V. Simultaneously, the FeSi electrode exhibits favorable cycling stability with 76% capacitance retention after 10 000 cycles and outstanding electrical conductivity. This finding provides a novel method of preparing a kind of untapped electrode material, porous FeSi nanoparticles derived from RLs, and the resulting FeSi material shows enormous potential for energy storage via high-performance SCs.
Wang Weiming,Wu Yuming,Yi Jie,Yang Yuhan,Shen Meiling,Yang Zhihui,Peng Shuai,Min Xue,Yang Xixian,Xiong Jun,Li Ming
Solar vapor production is considered an effective and environmentally friendly method of reducing freshwater shortages. However, designing an affordable solar evaporator with a simple method is still a challenge. Herein, motivated by the transpiration of plants, a full cattail leaf-based solar evaporator has been developed. In this solar evaporator, the photothermal membrane has been exploited by simply cross-linking the carbonized cattail leaf and the fibers from the alkali-treated cattail leaf with sodium alginate. The original cattail leaf with its square water transport channels and inherent hydrophilicity is employed to pump the bottom water to the upper photothermal membrane. Thanks to the synergistic effect between the photothermal membrane and the cattail leaf-based water transporter, the full cattail leaf-derived solar evaporator acquires an evaporation rate of 1.46 kg m –2 h –1 with a solar thermal efficiency of 87.48% under 1-solar (1 kW m –2 ). Fifteen-cycle experiments indicate that this solar evaporator has excellent stability. Outdoor experiments demonstrate that the full cattail leaf-based solar evaporator can effectively desalinate seawater and purify dyeing wastewater. Moreover, the total cost of the chemicals applied to manufacture 1 m 2 of cattail leaf-based photothermal membrane is approximately 3.1 dollars. This strategy is expected to turn freely available biomass into a potentially valuable solar evaporator with a simple cross-linking method and an affordable price that offers a promising future for alleviating the global freshwater crisis. Graphical abstract
危险品化学品经营许可证（带存储）