Engineering single atomic ruthenium on defective nickel vanadium layered double hydroxide for highly efficient hydrogen evolution

Fabricating single-atom catalysts(SACs)with high catalytic activity as well as great stability is a big challenge.Herein,we propose a precise synthesis strategy to stabilize single atomic ruthenium through regulating vanadium defects of nickel vanadium layered double hydroxides(NiV-LDH)ultrathin nanoribbons support.Correspondingly,the isolated atomically Ru doped NiV-LDH ultrathin nanoribbons(NiVRu-R)were successfully fabricated with a super-high Ru load of 12.8 wt.%.X-ray absorption spectrum(XAS)characterization further confirmed atomic dispersion of Ru.As catalysts for electrocatalytic hydrogen evolution reaction(HER)in alkaline media,the NiVRu-R demonstrated superior catalytic properties to the commercial Pt/C.Moreover,it maintained exceptional stability even after 5,000 cyclic voltammetry cycles.In-situ XAS and density functional theory(DFT)calculations prove that the Ru atomic sites are stabilized on supports through forming the Ru-O-V structure,which also help promote the catalytic properties through reducing the energy barrier on atomic Ru catalytic sites.

NiCoP 1D nanothorns grown on 3D hierarchically porous Ni films for high performance hydrogen evolution reaction

Highly efficient,cost-effective,and durable electrocatalysts for hydrogen evolution reaction(HER)in water splitting is crucial for ene rgy conversion and sto rage.Herein,we report NiCoP 1D nanothorn arrays grown on 3D porous Ni film current collectors(Ni/NiCoP)as the novel electrocatalytic electrodes.The 3D hierarchically porous nickel films containing large 7±2μm pores and small pores less than 1μm are obtained through using hydrogen bubbles dynamic template method.The NiCoP 1D nanothorns are about 70 nm in diameter and 4-8μm in length.The porous Ni/NiCoP electrocatalytic electrodes demonstrate much higher catalytic activity and remarkable stability for long-term HER.The excellent electrocatalytic performance might be attributed to the inherent nature of highly catalytic active NiCo bimetal phosphides and the unique architecture of 1D nanothorn active materials directly integrated on the 3D hierarchically porous metallic nickel conductive skeletons.The developed electrode has been fabricated to the integrated solar-driven seawater-splitting system.

三维MXenes异质结及其应用

MXenes因其独特的表面化学性质、可调的金属组份、良好的亲水性和较高的载流子浓度,近年来被广泛应用于诸多研究领域.与其他二维材料类似,MXenes可与其他材料进行复合构建异质结,形成MXenes基三维多孔材料,从而显著增强其反应活性,提升其相关性能.尤其是这些三维多孔MXenes材料所具有的三维结构和明确的孔径,可显著提高电化学过程中各种离子和电子的传输速率,因此在电化学能量存储、传感、催化和环境领域应用前景广阔.在这篇综述中,作者以MXenes/碳、MXenes/无机物和MXenes/聚合物这三种主要的MXenes基异质结为研究对象,系统地总结了近年来三维多孔MXenes基异质结的构建方法的研究进展.同时,深入探讨了三维多孔MXenes基异质结在光催化、环境监测和电化学储能中的应用进展.最后,详细归纳了三维多孔MXenes基异质结的孔隙形成机制、性质和应用之间的关系,并提出了作者独到的见解.本综述可为三维多孔MXenes基异质结在高性能材料和器件中的设计、制造和应用等方面提供指导.