Hierarchical Bi/S-modified Cu/brass mesh used as structured highly performance catalyst for CO_(2) electroreduction to formate

Electrocatalytic CO_(2) reduction reaction(ECO_(2)RR)converts CO_(2) to high-value chemical products and promotes the carbon cycle.Sulfur(S)-modified copper(Cu)and bismuth(Bi)-based catalysts have been recognized as promising catalysts for ECO_(2)RR.Both of them are highly active for selective formate generation,however,their poor stability and severe competing hydrogen evolution reaction(HER)remain challenging.Herein,S-doped Cu coated with Bi(Bi/Cu-S)is developed to improve ECO_(2)RR selectivity to formate.Bi/Cu-S/brass mesh(BM)electrode material for ECO_(2)RR was prepared by electrodepositing Bi on the surface of Cu-S/BM nanowires obtained from CuS/BM after the electroreduction.The Faradaic efficiency(FE)of the formate reaches the maximum of 94.3%at-0.9 V vs.reversible hydrogen electrode(RHE)with a partial current density as high as-50.7 mA·cm^(-2) and a yield of 30.7 mmol·h^(-1)·cm^(-2) under 0.5 M KHCO_(3) electrolyte.Meanwhile,the FE of formate is higher than 90%in the voltage range of-0.8 to-1.0 V vs.RHE.It also shows good stability at-0.9 V vs.RHE with the FE of formate remaining above 93%after a 10 h reaction.Density functional theory(DFT)calculations demonstrate that the Bi/Cu-S structure promotes the adsorption of CO_(2) and effectively inhibits HER by enhancing the adsorption of^(*)H to a great extent,improving the selective conversion of CO_(2) to formate.This work deepens the understanding of the mechanism of Cu-Bi-based catalysts and S-modified Cu-based catalysts in selective ECO_(2)RR to formate,and also provides a new strategy for catalyst design.

知识驱动的人力资源管理与员工越轨创新行为关系研究:基于自我决定理论的视角

越轨创新是促进企业创新的重要策略之一。基于自我决定理论,本研究探索了知识驱动的人力资源管理与员工越轨创新之间的关系,分析了内在动机和创新激情的中介作用及创新自我效能感的调节作用。研究显示知识驱动的人力资源管理有助于促进员工越轨创新,内在动机和创新激情是知识驱动的人力资源管理与员工越轨创新之间的中介变量,创新自我效能感会提升员工内在动机、创新激情在知识驱动的人力资源管理与越轨创新之间的中介效应。研究表明企业应当实施知识驱动型人力资源管理模式,提升员工的内在工作动机,并通过培育员工创新自我效能感,激发员工越轨创新行为。

Fabrication of a three-dimensional micro/nanocarbon structure with sub-10 nm carbon fiber arrays based on the nanoforming and pyrolysis of polyacrylonitrile-based jet fibers

To produce a three-dimensional micro/nanocarbon structure,a manufacturing design technique for sub-10 nm carbon fiber arrays on three-dimensional carbon micropillars has been developed;the method involves initiating electrostatic jetting,forming submicron-to-nanoscale PAN-based fibers,and maximizing the shrinkage from polyacrylonitrile(PAN)-based fibers to carbon fibers.Nanoforming and nanodepositing methods for polyacrylonitrilebased jet fibers as precursors of carbon fibers are proposed for the processing design of electrostatic jet initiation and for the forming design of submicron-to-nanoscale PAN-based fibers by establishing and analyzing mathematical models that include the diameter and tensile stress values of jet fibers and the electric field intensity values on the surfaces of carbon micropillars.In accordance with these methods,an array of jet fibers with diameters of~80 nm is experimentally formed based on the thinning of the electrospinning fluid on top of a dispensing needle,the poking of drum into an electrospinning droplet,and the controlling of the needle–drum distance.When converting thin PANbased jet fibers to carbon fibers,a pyrolysis method consisting of the suspension of jet nanofibers between carbon micropillars,the bond between the fibers and the surface of the carbon micropillar,and the control of micropillar spacing,stabilization temperature,and carbonation rate is presented to maximize the shrinkage from PAN-based fibers to carbon fibers and to form sub-10 nm carbon fiber arrays between three-dimensional carbon micropillars.The manufacturing design of a three-dimensional micro/nanocarbon structure can produce thin PAN-based jet nanofibers and nanofiber arrays aligned on micropillar surfaces,obtain shrinkage levels reaching 96%and incorporate sub-10 nm carbon fibers into three-dimensional carbon micropillars;these actions provide new research opportunities for correlated three-dimensional micro/nanocarbon structures that have not previously been technically possible.

Fabrication of crystalline submicro-to-nano carbon wire for achieving high current density and ultrastable current

Crystalline carbon nanowire arrays were fabricated taking advantage of near-field electrospinning and stress decyanation.A novel fabrication method for carbon nanowires with radii ranging from~2.15μm down to~25 nm was developed based on implementing nitrogen pretreatment on the silica surface and then aligning polymer nanofibers during near-field electrospinning at an ultralow voltage.Stress decyanation was implemented by subsequently pyrolyzing a polymer nanofiber array on the silica surface at 1000°C for 1 h in an N_(2)atmosphere,thus obtaining a crystalline carbon nanowire array with a nanostructured surface.Various crystalline nanostructures were fabricated on the nanowire surface,and their electrochemical performance was evaluated by cyclic voltammetry(CV)and electrochemical impedance spectroscopy(EIS).Crystalline carbon wires with diameters ranging from micrometers to submicrometers displayed carbon nanoelectrode-like behavior with their CV curve having a sigmoidal shape.A highly crystalline carbon nanowire array showed distinct behavior,having a monotonically increasing straight line as its CV curve and a semicircular EIS spectrum;these results demonstrated its ultrastable current,as determined by electron transfer.Furthermore,nanocrystalline-structured carbon wires with diameters of~305 nm displayed at least a fourfold higher peak current density during CV(4000 mA/m2)than highly crystalline carbon nanowires with diameters of~100 nm and porous microwires with diameters of~4.3μm.