In order to develop a marine engineering material with excellent mechanical properties and corrosion resistance,a novel non-equiatomic Co_(1.5)CrFeNi_(1.5)Ti_(0.6)high-entropy alloy(HEA)was fabricated through mechanic...In order to develop a marine engineering material with excellent mechanical properties and corrosion resistance,a novel non-equiatomic Co_(1.5)CrFeNi_(1.5)Ti_(0.6)high-entropy alloy(HEA)was fabricated through mechanical alloying and spark plasma sintering.The results revealed that the sintering temperature significantly affected the microstructure and phase composition of the HEA owing to the diffusion rate,homogenization,and sluggish diffusion effect of metal atoms.At sintering temperatures below 1050℃,HEA mainly consisted of face-centered cubic(FCC),Ni_(3)Ti(ε),Ni_(2.67)Ti_(1.33)(R),and Fe-Cr(σ)phases.The microstructure of alloy comprised coarse dendritic crystals,whose content and size gradually decreased with increasing sintering temperature.However,the HEA sintered above 1100℃contained only fine equiaxed crystals.HEA sintered at 1100℃featured only the FCC solid solution,while theε-phase precipitated at temperatures above 1150℃.At a sintering temperature of 1050℃,the alloy microstructure consisted of short rod-like dendrites and fine equiaxed crystals.This alloy achieved the highest yield strength of 1198.71 MPa owing to the effects of precipitation strengthening and grain boundary strengthening.Meanwhile,HEA sintered above 1050℃exhibited significantly improved corrosion resistance.Considering the microstructure,mechanical,and corrosion properties,1050℃was identified as the optimal sintering temperature for Co_(1.5)CrFeNi_(1.5)Ti_(0.6)HEA.展开更多
Electrocatalytic toluene(TL)oxidation to produce benzoic acid(BAC)process is largely hindered due to sluggish kinetics associated with the transformation of the rate-determining step,because of weak TL adsorption and ...Electrocatalytic toluene(TL)oxidation to produce benzoic acid(BAC)process is largely hindered due to sluggish kinetics associated with the transformation of the rate-determining step,because of weak TL adsorption and high rate-determining step energy barrier for difficult to dehydrogenate.Herein,we report Mn_(x)Ce_(1-x)O_(2)/CNT catalyst for accelerated reaction kinetics.Theoretical and experimental studies indicate that Ce sites promote TL adsorption and polyvalent Mn modulates the electronic structure of Ce sites reducing the rate-determining step energy barrier.This results in increasing^(*)C_(6)H_(5)CH_(2)coverage and effectively accelerating TL oxidation reaction(TOR)kinetics.Excitingly,the Faraday efficiency(FE)and BAC yield of optimized Mn_(0.6)Ce_(0.4)O_(2)/CNT at 2.6 V vs.RHE could reach 85.9%and 653.9 mg h^(-1)cm^(-2),respectively.In addition,the Mn_(0.6)Ce_(0.4)O_(2)/CNT displays a high selectivity of 96.3%for BAC.Combining the TL oxidation reaction with hydrogen evolution reaction,the anion exchange membrane electrolyzer of Mn_(0.6)Ce_(0.4)O_(2)/CNT(+)||Pt/C(-)can reach 100 mA cm^(-2)at the voltage of 3.0 V,in which the BAC yield is 579.4 mg h^(-1)cm^(-2)and the FE is 83.6%.This work achieved high selectivity of TOR at industrial-relevant current densities of 100 mA cm^(-2)at the low voltage for the first time.展开更多
Herein,UiO-66-NH_(2) nanoparticles were solvothermally immobilized onto Zn_(0.4)Cd_(0.6)S nanorods in varying amounts.The resulting UiO-66-NH_(2)/Zn_(0.4)Cd_(0.6)S hybrid architectures demonstrated UiO-66-NH_(2) conte...Herein,UiO-66-NH_(2) nanoparticles were solvothermally immobilized onto Zn_(0.4)Cd_(0.6)S nanorods in varying amounts.The resulting UiO-66-NH_(2)/Zn_(0.4)Cd_(0.6)S hybrid architectures demonstrated UiO-66-NH_(2) contentdependent photocatalytic activity for visible-light-driven hydrogen peroxide(H_(2)O_(2))production from pure water.Notably,the optimized UiO-66-NH_(2)/Zn_(0.4)Cd_(0.6)S-0.2 catalyst achieved the highest H_(2)O_(2) yield under visible-light illumination,surpassing those of pure UiO-66-NH_(2) and bare Zn_(0.4)Cd_(0.6)S by factors of 81.12 and 2.22,respectively.In addition,the UiO-66-NH_(2)/Zn_(0.4)Cd_(0.6)S-0.2 sample exhibited outstanding photocatalytic efficiency,achieving an NH3 concentration of 25.02±0.68 mg L^(−1) after 1 h of visible-light exposure and an H_(2) evolution of 487.12 mmol g^(−1) following 3 h of irradiation.The notable enhancement in the photocatalytic performance was attributed to efficient S-scheme charge transfer,as confirmed by transient absorption spectroscopy.The S-scheme charge migration mechanism in the UiO-66-NH_(2)/Zn_(0.4)Cd_(0.6)S system was further validated by electron paramagnetic resonance,density functional theory calculations,and in situ irradiated X-ray photoelectron spectroscopy.Overall,this study presents a promising strategy for designing highly efficient hybrid architectures for photocatalytic applications.展开更多
基金supported by Special Fund for the Development of 1500-Meter Subsea Christmas Trees and Control Systems.
文摘In order to develop a marine engineering material with excellent mechanical properties and corrosion resistance,a novel non-equiatomic Co_(1.5)CrFeNi_(1.5)Ti_(0.6)high-entropy alloy(HEA)was fabricated through mechanical alloying and spark plasma sintering.The results revealed that the sintering temperature significantly affected the microstructure and phase composition of the HEA owing to the diffusion rate,homogenization,and sluggish diffusion effect of metal atoms.At sintering temperatures below 1050℃,HEA mainly consisted of face-centered cubic(FCC),Ni_(3)Ti(ε),Ni_(2.67)Ti_(1.33)(R),and Fe-Cr(σ)phases.The microstructure of alloy comprised coarse dendritic crystals,whose content and size gradually decreased with increasing sintering temperature.However,the HEA sintered above 1100℃contained only fine equiaxed crystals.HEA sintered at 1100℃featured only the FCC solid solution,while theε-phase precipitated at temperatures above 1150℃.At a sintering temperature of 1050℃,the alloy microstructure consisted of short rod-like dendrites and fine equiaxed crystals.This alloy achieved the highest yield strength of 1198.71 MPa owing to the effects of precipitation strengthening and grain boundary strengthening.Meanwhile,HEA sintered above 1050℃exhibited significantly improved corrosion resistance.Considering the microstructure,mechanical,and corrosion properties,1050℃was identified as the optimal sintering temperature for Co_(1.5)CrFeNi_(1.5)Ti_(0.6)HEA.
基金supported by the National Natural Science Foundation of China(52272222)the Taishan Scholar Young Talent Program(tsqn201909114,tsqn201909123)the University Youth Innovation Team of Shandong Province(202201010318)。
文摘Electrocatalytic toluene(TL)oxidation to produce benzoic acid(BAC)process is largely hindered due to sluggish kinetics associated with the transformation of the rate-determining step,because of weak TL adsorption and high rate-determining step energy barrier for difficult to dehydrogenate.Herein,we report Mn_(x)Ce_(1-x)O_(2)/CNT catalyst for accelerated reaction kinetics.Theoretical and experimental studies indicate that Ce sites promote TL adsorption and polyvalent Mn modulates the electronic structure of Ce sites reducing the rate-determining step energy barrier.This results in increasing^(*)C_(6)H_(5)CH_(2)coverage and effectively accelerating TL oxidation reaction(TOR)kinetics.Excitingly,the Faraday efficiency(FE)and BAC yield of optimized Mn_(0.6)Ce_(0.4)O_(2)/CNT at 2.6 V vs.RHE could reach 85.9%and 653.9 mg h^(-1)cm^(-2),respectively.In addition,the Mn_(0.6)Ce_(0.4)O_(2)/CNT displays a high selectivity of 96.3%for BAC.Combining the TL oxidation reaction with hydrogen evolution reaction,the anion exchange membrane electrolyzer of Mn_(0.6)Ce_(0.4)O_(2)/CNT(+)||Pt/C(-)can reach 100 mA cm^(-2)at the voltage of 3.0 V,in which the BAC yield is 579.4 mg h^(-1)cm^(-2)and the FE is 83.6%.This work achieved high selectivity of TOR at industrial-relevant current densities of 100 mA cm^(-2)at the low voltage for the first time.
基金supported by the Natural Science Foundation of Zhejiang Province(LTGS24E020001,LZY24E020001)National Natural Science Foundation of China(52102288)+1 种基金the Project for Science and Technology Innovation Leading Talents of Zhejiang Provincial High-level Talents Special Support Plan(2021R52028)Open Foundation of State Key Laboratory of Environmental Criteria and Risk Assessment,Chinese Research Academy of Environmental Sciences(SKLECRA2022OFP03).
文摘Herein,UiO-66-NH_(2) nanoparticles were solvothermally immobilized onto Zn_(0.4)Cd_(0.6)S nanorods in varying amounts.The resulting UiO-66-NH_(2)/Zn_(0.4)Cd_(0.6)S hybrid architectures demonstrated UiO-66-NH_(2) contentdependent photocatalytic activity for visible-light-driven hydrogen peroxide(H_(2)O_(2))production from pure water.Notably,the optimized UiO-66-NH_(2)/Zn_(0.4)Cd_(0.6)S-0.2 catalyst achieved the highest H_(2)O_(2) yield under visible-light illumination,surpassing those of pure UiO-66-NH_(2) and bare Zn_(0.4)Cd_(0.6)S by factors of 81.12 and 2.22,respectively.In addition,the UiO-66-NH_(2)/Zn_(0.4)Cd_(0.6)S-0.2 sample exhibited outstanding photocatalytic efficiency,achieving an NH3 concentration of 25.02±0.68 mg L^(−1) after 1 h of visible-light exposure and an H_(2) evolution of 487.12 mmol g^(−1) following 3 h of irradiation.The notable enhancement in the photocatalytic performance was attributed to efficient S-scheme charge transfer,as confirmed by transient absorption spectroscopy.The S-scheme charge migration mechanism in the UiO-66-NH_(2)/Zn_(0.4)Cd_(0.6)S system was further validated by electron paramagnetic resonance,density functional theory calculations,and in situ irradiated X-ray photoelectron spectroscopy.Overall,this study presents a promising strategy for designing highly efficient hybrid architectures for photocatalytic applications.
