Superwetting Ag/α-Fe_(2)O_(3) anchored mesh with enhanced photocatalytic and antibacterial activities for efficient water purification

Superwetting materials have drawn unprecedented attention in the treatment of oily wastewater due to their preferable anti-fouling property and selective oil/water separation.However,it is still a challenge to fabricate multifunctional and environmentally friendly materials,which can be stably applied to purify the actual complicated wastewater.Here,a Ag/Ag/α-Fe_(2)O_(3) heterostructure anchored copper mesh was intentionally synthesized using a facile two-step hydrothermal method.The resultant mesh with superhydrophilicity and underwater superoleophobicity was capable of separating various oil/water mixtures with superior separation efficiency and high permeationflux driven by gravity.Benefiting from the joint effects of the smaller band gap of Ag/α-Fe_(2)O_(3) heterojunction,inherent antibacterial capacity of Ag/α-Fe_(2)O_(3) and Ag nanoparticles,favorable conductive substrate,as well as the hierarchical structure with superwettability,such mesh presented remarkably enhanced degradation capability toward organic dyes under visible light irradiation and antibacterial activity against both Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)compared with the pure Ag/α-Fe_(2)O_(3) coated mesh.Impressively,the mesh exhibited bifunctional water purification performance,in which organic dyes were eliminated simultaneously from water during oil/water separation in onefiltration process.More importantly,this mesh behaved exceptional chemical resistance,mechanical stability and long-term reusability.Therefore,this material with multifunctional integration may hold promising potential for steady water purification in practice.

Porous carbon matrix-encapsulated MnO in situ derived from metalorganic frameworks as advanced anode materials for Li-ion capacitors

Conversion-type anode materials hold great potential for Li+storage applications owing to their high specific capacity,while large volume expansion and poor electrical conductivity limit their rate and cycling performances.Herein,a bimetal ZnMn-based metal-organic framework(ZnMn-MOF)is engineered for in situ conversion of MnO-encapsulated porous carbon(MnO/PC)composite.The templating and activation effects of coordinated Zn endow the converted PC matrix with a highly porous structure.This enhances the compatibility of PC matrix with MnO particles,resulting in the full encapsulation of MnO particles in the PC matrix.More significantly,the PC matrix provides enough void space to buffer the volume change,which fully wraps the MnO without crack or fracture during repeated cycling.As a result,MnO/PC shows high charge storage capability,extraordinary rate performance,and long-term cycling stability at the same time.Thus MnO/PC exhibits high delithiation capacities of 768mA h g^(-1)at 0.1Ag^(-1)and 487mA h g^(-1)at a high rate of 0.7Ag^(-1),combined with an unattenuated cycling performance after 500 cycles at 0.3Ag^(-1).More significantly,MnO/PC demonstrates a well-matched performance with the capacitive activated carbon electrode in a Li-ion capacitor(LIC)full cell.LIC demonstrates a high specific energy of 153.6W h kg^(-1)at 210W kg^(-1),combined with a specific energy of 71.8W h kg^(-1)at a high specific power of 63.0kW kg^(-1).

具有优越镍-锌电池性能的低结晶镍钴氢氧化物

因具有大量的晶界和离子扩散通道,低结晶度的电极活性材料有望在储能领域中实现更好的性能.然而在大多数应用中通常是结晶良好的样品具有更好的稳定性,稳定性较差限制了低结晶样品在相关研究领域的应用.本文利用一种溶剂热法调控N-甲基吡咯烷酮和水混合溶剂的体积比以合成低结晶度的镍钴氢氧化物(NiCo-OH-L).研究发现,将合成的镍钴氢氧化物用作镍-锌电池正极时,NiCo-OH-L不仅表现出与高结晶度的同类样品相当的循环稳定性能,而且在1-50 A g^(-1)的电流范围内显示出更高的容量以及容量保持率.其优异的电化学性能可归因于低结晶的结构,显著提高的比表面积和降低的电荷转移电阻.此外,NiCo-OH-L的钴组分进一步提高了倍率和循环稳定性能.NiCo-OH-L在1 A g^(-1)时的比容量达到238.9 mA h g^(-1),当电流密度升至50 A g^(-1)时的容量仍有116.4 mA h g^(-1),显示出高容量和高倍率性能.不仅如此,由NiCo-OH-L组装成的镍-锌电池在不同的电流和循环周期下也表现出较高的性能.