Electrocatalytic overall water splitting(OWS),a pivotal approach in addressing the global energy crisis,aims to produce hydrogen and oxygen.However,most of the catalysts in powder form are adhesively bounding to the e...Electrocatalytic overall water splitting(OWS),a pivotal approach in addressing the global energy crisis,aims to produce hydrogen and oxygen.However,most of the catalysts in powder form are adhesively bounding to the electrodes,resulting in catalyst detachment by bubble generation and other uncertain interference,and eventually reducing the OWS performance.To surmount this challenge,we synthesized a hybrid material of Co_(3)S_(4)-pyrolysis lotus fiber(labeled as Co_(3)S_(4)-p LF)textile by hydrothermal and hightemperature pyrolysis processes for electrocatalytic OWS.Owing to the natural LF textile exposing the uniformly distributed functional groups(AOH,ANH_(2),etc.)to anchor Co_(3)S_(4)nanoparticles with hierarchical porous structure and outstanding hydrophily,the hybrid Co_(3)S_(4)-p LF catalyst shows low overpotentials at 10 m A cm^(-2)(η_(10,HER)=100 m Vη_(10,OER)=240 mV)alongside prolonged operational stability during electrocatalytic reactions.Theoretical calculations reveal that the electron transfer from p LF to Co_(3)S_(4)in the hybrid Co_(3)S_(4)-p LF is beneficial to the electrocatalytic process.This work will shed light on the development of nature-inspired carbon-based materials in hybrid electrocatalysts for OWS.展开更多
Hierarchical nanostructure construction and electronic structure engineering are commonly employed to increase the electrocatalytic activity of HER electrocatalysts.Herein,Ni doped Co_(3)S_(4) hierarchical nanosheets ...Hierarchical nanostructure construction and electronic structure engineering are commonly employed to increase the electrocatalytic activity of HER electrocatalysts.Herein,Ni doped Co_(3)S_(4) hierarchical nanosheets on Ti mesh(Ni doped Co_(3)S_(4) HNS/TM)were successfully prepared by using metal organic framework(MOF)as precursor which was synthesized under ambient condition.Characterization results confirmed this structure and Ni incorporation into Co_(3)S_(4) lattice as well as the modified electronic structure of Co_(3)S_(4) by Ni doping.Alkaline HER performance showed that Ni doped Co_(3)S_(4) HNS/TM presented outstanding HER activity with 173 m V overpotential at-10 m A·cm^(-2),surpassing most of metal sulfide-based electrocatalysts.The hierarchical structure,superior electrical conductivity and electronic structure modulation contributed to the accelerated water dissociation and enhanced intrinsic activity.This work provides a new avenue for synthesizing hierarchical nanostructure and simultaneously tuning the electronic structure to promote HER performance,which has potential application in designing highly efficient and cost-effective HER nanostructured electrocatalyst.展开更多
The rechargeable Mg-S batteries are attractive because of their resource abundances of Mg and S,high volumetric energy density,and less dendrite property of Mg anodes.However,the development is barred by the intrinsic...The rechargeable Mg-S batteries are attractive because of their resource abundances of Mg and S,high volumetric energy density,and less dendrite property of Mg anodes.However,the development is barred by the intrinsic low electronic conductivity of S and the discharge products as well as the lack of understanding the hidden electrochemical kinetics.Here,a Co_(3)S_(4)@MXene heterostructure is proposed as effective sulfur host for reversible Mg-S batteries.XPS results and density functional theory(DFT)calculation confirm that the chemical interaction between the decorated Co_(3)S_(4)nanocrystals host and polysulfide intermediates could well absorb and catalyze the polysulfides conversion,thus improve the electrochemical redox kinetics.Meanwhile,the MXene matrix could promote Mg ion diffusion dynamics greatly.As a result,the developed Mg-S batteries using the Co_(3)S_(4)@MXene-S as the cathode material could demonstrate high sulfur utilization with specific capacity of 1220 mAh g^(-1) and retain a capacity of 528 mAh g^(-1) after 100 cycles,together with a satisfactory rate performance even at 2 C.This work shed light on the advanced cathode design for reversible high energy Mg-S batteries.展开更多
制备高效的OER电催化剂对水裂解制氢至关重要.具有丰富配位构型的MOFs可以衍生出各种优良的电催化材料.由于石墨炔(GDY)具有独特的可控合成特性,我们将其原位复合在MOF衍生的Co_(3)S_(4)/NF材料上,获得了自支撑电极GDY/Co_(3)S_(4)/NF,...制备高效的OER电催化剂对水裂解制氢至关重要.具有丰富配位构型的MOFs可以衍生出各种优良的电催化材料.由于石墨炔(GDY)具有独特的可控合成特性,我们将其原位复合在MOF衍生的Co_(3)S_(4)/NF材料上,获得了自支撑电极GDY/Co_(3)S_(4)/NF,大大提高了其OER催化性能.研究表明,GDY/Co_(3)S_(4)/NF在10 mA cm^(-2)电流密度下表现出223 mV的低过电位,在100 mA cm^(-2)的大电流密度下,能够稳定电解45小时左右,该材料显示出了巨大的实际应用潜力.结果表明,由于GDY独特的炔键和大孔结构,它可以通过强电子相互作用与Co_(3)S_(4)相互作用,从而调节电子结构并提供有效的电荷转移通道,从而大大提高了其电催化OER的性能.展开更多
Exploring new and efficient photocatalysts to boost photocatalytic CO_(2) reduction is of critical importance for solar-to-fuel conversion.In this study,through the in-situ growth method,a series of S-scheme mechanism...Exploring new and efficient photocatalysts to boost photocatalytic CO_(2) reduction is of critical importance for solar-to-fuel conversion.In this study,through the in-situ growth method,a series of S-scheme mechanism Bi_(2)S_(3)/BiVO_(4)/Mn_(0.5)Cd_(0.5)S-DETA nanocomposites with good photocatalytic activity were synthesized.The extremely small size of Mn_(0.5)Cd_(0.5)S-DETA nanoparticles provides more active sites for photocatalytic reactions.In order to solve the serious shortcomings of sulfide photo-corrosion,BiVO_(4) were introduced as oxidation catalyst to consume too many holes and improve the stability of the material.In addition,the in-situ growth method produces the reduction cocatalyst Bi_(2)S_(3) during the BiVO_(4) and Mn_(0.5)Cd_(0.5)S-DETA recombination process,thereby improving the efficiency of charge transfer at their interface contact.The ternary composite unveils a higher CO_(2)-reduction rate(44.74μmol g^(−1) h^(−1))comparing with pristine BiVO_(4)(14.11μmol g^(−1) h^(−1)).The enhanced photocatalytic CO_(2) reduction performance is due to the special interface structure of the S-scheme Bi_(2)S_(3)/BiVO_(4)/Mn_(0.5)Cd_(0.5)S-DETA photocatalyst,which facilitates the charge separation at the interface and improves its photocatalytic activity and stability.展开更多
Effects of the Co_(3)O_(4)nanoparticle on the phase formation,microstructure and dielectric properties of barium titanate ceramics are investigated in this study.Co_(3)O_(4)-doped BaTiO_(3)ceramics were prepared by th...Effects of the Co_(3)O_(4)nanoparticle on the phase formation,microstructure and dielectric properties of barium titanate ceramics are investigated in this study.Co_(3)O_(4)-doped BaTiO_(3)ceramics were prepared by the conventional mixed oxide method followed by normal sintering in air.Systematic studies of X-ray diffraction(XRD),scanning electron microscopy and dielectric spectroscopy with varying doping levels were performed.The cell parameters,tetragonality and crystallite size of doped ceramics also were calculated from XRD data.Results showed that the single phase of BaTiO_(3)gave no evidence of unwanted peak forms in any of the samples.Cubic phase occurred after adding Co_(3)O_(4)at 0.25 mol%.Various grain sizes and shapes were found in this system.Finally,adding Co_(3)O_(4)in BaTiO_(3)ceramics resulted in shifting of the Curie point to a lower temperature.The composition,x=0.25,showed different dielectric behavior,which related to appearance of the cubic phase and¯ne grain microstructure.展开更多
基金supported by the Scientific Research Foundation of Hunan Provincial Education Department,China(22B0893)the Scientific Research Foundation of Hunan Provincial Education Department,China(20A060)。
文摘Electrocatalytic overall water splitting(OWS),a pivotal approach in addressing the global energy crisis,aims to produce hydrogen and oxygen.However,most of the catalysts in powder form are adhesively bounding to the electrodes,resulting in catalyst detachment by bubble generation and other uncertain interference,and eventually reducing the OWS performance.To surmount this challenge,we synthesized a hybrid material of Co_(3)S_(4)-pyrolysis lotus fiber(labeled as Co_(3)S_(4)-p LF)textile by hydrothermal and hightemperature pyrolysis processes for electrocatalytic OWS.Owing to the natural LF textile exposing the uniformly distributed functional groups(AOH,ANH_(2),etc.)to anchor Co_(3)S_(4)nanoparticles with hierarchical porous structure and outstanding hydrophily,the hybrid Co_(3)S_(4)-p LF catalyst shows low overpotentials at 10 m A cm^(-2)(η_(10,HER)=100 m Vη_(10,OER)=240 mV)alongside prolonged operational stability during electrocatalytic reactions.Theoretical calculations reveal that the electron transfer from p LF to Co_(3)S_(4)in the hybrid Co_(3)S_(4)-p LF is beneficial to the electrocatalytic process.This work will shed light on the development of nature-inspired carbon-based materials in hybrid electrocatalysts for OWS.
基金funded by National Natural Science Foundation of China(Nos.21906008 and 51571076)Open Project of State Key Laboratory of Urban Water Resource and Environment of Har-bin Institute of Technology(No.HCK201716)+1 种基金Chongqing Basic and Frontier Research Program(cstc2018jcyjAX0774)Science and Technology Research Program of Chongqing Municipal Education Commission(Nos.KJQN201901420 and KJQN202001413).
文摘Hierarchical nanostructure construction and electronic structure engineering are commonly employed to increase the electrocatalytic activity of HER electrocatalysts.Herein,Ni doped Co_(3)S_(4) hierarchical nanosheets on Ti mesh(Ni doped Co_(3)S_(4) HNS/TM)were successfully prepared by using metal organic framework(MOF)as precursor which was synthesized under ambient condition.Characterization results confirmed this structure and Ni incorporation into Co_(3)S_(4) lattice as well as the modified electronic structure of Co_(3)S_(4) by Ni doping.Alkaline HER performance showed that Ni doped Co_(3)S_(4) HNS/TM presented outstanding HER activity with 173 m V overpotential at-10 m A·cm^(-2),surpassing most of metal sulfide-based electrocatalysts.The hierarchical structure,superior electrical conductivity and electronic structure modulation contributed to the accelerated water dissociation and enhanced intrinsic activity.This work provides a new avenue for synthesizing hierarchical nanostructure and simultaneously tuning the electronic structure to promote HER performance,which has potential application in designing highly efficient and cost-effective HER nanostructured electrocatalyst.
基金This work was financially supported by the National Natu-ral Science Foundation of China(No.21603019)the Opening Project of State Key Laboratory of High Performance Ce-ramics and Superfine Microstructure(SKL201807SIC)program for the Hundred Talents Program of Chongqing University.
文摘The rechargeable Mg-S batteries are attractive because of their resource abundances of Mg and S,high volumetric energy density,and less dendrite property of Mg anodes.However,the development is barred by the intrinsic low electronic conductivity of S and the discharge products as well as the lack of understanding the hidden electrochemical kinetics.Here,a Co_(3)S_(4)@MXene heterostructure is proposed as effective sulfur host for reversible Mg-S batteries.XPS results and density functional theory(DFT)calculation confirm that the chemical interaction between the decorated Co_(3)S_(4)nanocrystals host and polysulfide intermediates could well absorb and catalyze the polysulfides conversion,thus improve the electrochemical redox kinetics.Meanwhile,the MXene matrix could promote Mg ion diffusion dynamics greatly.As a result,the developed Mg-S batteries using the Co_(3)S_(4)@MXene-S as the cathode material could demonstrate high sulfur utilization with specific capacity of 1220 mAh g^(-1) and retain a capacity of 528 mAh g^(-1) after 100 cycles,together with a satisfactory rate performance even at 2 C.This work shed light on the advanced cathode design for reversible high energy Mg-S batteries.
基金supported by the National Natural Science Foundation of China (22375148)the National Key R&D Program of China (2022YFA1502902)。
文摘制备高效的OER电催化剂对水裂解制氢至关重要.具有丰富配位构型的MOFs可以衍生出各种优良的电催化材料.由于石墨炔(GDY)具有独特的可控合成特性,我们将其原位复合在MOF衍生的Co_(3)S_(4)/NF材料上,获得了自支撑电极GDY/Co_(3)S_(4)/NF,大大提高了其OER催化性能.研究表明,GDY/Co_(3)S_(4)/NF在10 mA cm^(-2)电流密度下表现出223 mV的低过电位,在100 mA cm^(-2)的大电流密度下,能够稳定电解45小时左右,该材料显示出了巨大的实际应用潜力.结果表明,由于GDY独特的炔键和大孔结构,它可以通过强电子相互作用与Co_(3)S_(4)相互作用,从而调节电子结构并提供有效的电荷转移通道,从而大大提高了其电催化OER的性能.
基金This work was supported by the National Natural Science Foundation of China(Nos.51572103 and 51973078)the Distinguished Young Scholar of Anhui Province(No.1808085J14)+1 种基金the Major projects of Education Department of Anhui Province(No.KJ2020ZD005)the Key Foundation of Educational Commission of Anhui Province(No.KJ2019A0595).
文摘Exploring new and efficient photocatalysts to boost photocatalytic CO_(2) reduction is of critical importance for solar-to-fuel conversion.In this study,through the in-situ growth method,a series of S-scheme mechanism Bi_(2)S_(3)/BiVO_(4)/Mn_(0.5)Cd_(0.5)S-DETA nanocomposites with good photocatalytic activity were synthesized.The extremely small size of Mn_(0.5)Cd_(0.5)S-DETA nanoparticles provides more active sites for photocatalytic reactions.In order to solve the serious shortcomings of sulfide photo-corrosion,BiVO_(4) were introduced as oxidation catalyst to consume too many holes and improve the stability of the material.In addition,the in-situ growth method produces the reduction cocatalyst Bi_(2)S_(3) during the BiVO_(4) and Mn_(0.5)Cd_(0.5)S-DETA recombination process,thereby improving the efficiency of charge transfer at their interface contact.The ternary composite unveils a higher CO_(2)-reduction rate(44.74μmol g^(−1) h^(−1))comparing with pristine BiVO_(4)(14.11μmol g^(−1) h^(−1)).The enhanced photocatalytic CO_(2) reduction performance is due to the special interface structure of the S-scheme Bi_(2)S_(3)/BiVO_(4)/Mn_(0.5)Cd_(0.5)S-DETA photocatalyst,which facilitates the charge separation at the interface and improves its photocatalytic activity and stability.
文摘Effects of the Co_(3)O_(4)nanoparticle on the phase formation,microstructure and dielectric properties of barium titanate ceramics are investigated in this study.Co_(3)O_(4)-doped BaTiO_(3)ceramics were prepared by the conventional mixed oxide method followed by normal sintering in air.Systematic studies of X-ray diffraction(XRD),scanning electron microscopy and dielectric spectroscopy with varying doping levels were performed.The cell parameters,tetragonality and crystallite size of doped ceramics also were calculated from XRD data.Results showed that the single phase of BaTiO_(3)gave no evidence of unwanted peak forms in any of the samples.Cubic phase occurred after adding Co_(3)O_(4)at 0.25 mol%.Various grain sizes and shapes were found in this system.Finally,adding Co_(3)O_(4)in BaTiO_(3)ceramics resulted in shifting of the Curie point to a lower temperature.The composition,x=0.25,showed different dielectric behavior,which related to appearance of the cubic phase and¯ne grain microstructure.
