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.

Three-dimensional MXenes heterostructures and their applications

Due to their unique surface chemistry,highly adjustable metal components,hydrophilicity,and high carrier concentrations,MXenes are applied in a variety of scenarios.Similar to other two-dimensional(2D)materials,building heterostructures with additional materials to form a 3D porous architecture for MXenes can significantly enhance their functionality and reactivity.Notably,the open structures and well-defined pathways of these 3D structured MXenes can improve ionic and electronic transport,thereby promoting their applications in electrochemical energy storage,sensing,catalysis,and environment.In this review,the recent efforts made on preparing 3D porous MXenes with heterostructures,focusing on MXenes/C,MXenes/inorganics,and MXenes/polymers were summarized.The discussion covers aspects ranging from the design to synthesis of 3D porous MXenes,and their applications in photocatalysis,environmental monitoring and electrochemical energy storage.This review is concluded by presenting the prospects and insights on exploring the relationships between the porosity formation mechanisms,properties and applications of the 3D porous MXenes heterostructures.This review can provide meaningful guidance for the design,fabrication and application of 3D porous MXenes in high-performance materials and devices.

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.