Ni coating and Ni-Co alloy coatings were produced by adjusting the composition of the plating solution using a direct current electrodepositing process. The oxidation behaviors of nickel and nickel-cobalt alloys in ai...Ni coating and Ni-Co alloy coatings were produced by adjusting the composition of the plating solution using a direct current electrodepositing process. The oxidation behaviors of nickel and nickel-cobalt alloys in air at 960 ℃ were studied by thermogravimetric （TG） analyzer and then the formed oxide scales were examined by scanning electron microscopy/energy dispersive spectroscopy （SEM/EDS）, X-ray diffractometry （XRD）, and Raman spectroscopy. The scale morphologies, composition, grain size and mechanism of oxidation were discussed in detail. The results show that oxidation rates ofNi, Ni-7%Co （mass fraction） and Ni-15%Co generally follow parabolic relationship, whereas that of Ni-30% Co alloy follows cubic relationship. The higher the Co content of the alloys is, the faster the oxidation rate is. Metal concentration profiles reveal cobalt depletion in the alloy surface beneath oxide scales, and a progressive＇enrichment in cobalt towards the outer surface of the scale.展开更多
The hierarchical structure of molybdenum disulfide(MoS2)nanosheet arrays stemmed from nickelcobalt layered double hydroxide(NiCo-LDH)/carbon cloth was prepared by growing the MoS_(2) nanosheet arrays onto the NiCo-LDH...The hierarchical structure of molybdenum disulfide(MoS2)nanosheet arrays stemmed from nickelcobalt layered double hydroxide(NiCo-LDH)/carbon cloth was prepared by growing the MoS_(2) nanosheet arrays onto the NiCo-LDH template which was pre-deposited onto the carbon cloth substrate.In this electrode configuration,carbon cloth is the three dimensional and conductive skeleton;NiCo-LDH nanosheets,as the template,ensure the oriented growth of MoS2 nanosheet arrays.Therefore,more MoS_(2) active sites are exposed and the catalyst exhibits good hydrogen evolution reaction activity.展开更多
1,8-Dioxo-octahydroxanthenes (4a-4f) and 1,8-dioxohexahydroacridines (5a-5c) were synthesized by novel, simple and eco-friendly method with higher yields in the presence of magnetically separable nano nickel-cobalt fe...1,8-Dioxo-octahydroxanthenes (4a-4f) and 1,8-dioxohexahydroacridines (5a-5c) were synthesized by novel, simple and eco-friendly method with higher yields in the presence of magnetically separable nano nickel-cobalt ferrite catalyst (Ni0.5Co0.5Fe2O4). The former, 1,8-dioxo-octahydroxanthenes have been synthesized from dimedone and different aromatic aldehydes, while the latter from this mixture are along with ammonium acetate. The main advantage of this method is that the nano catalyst can be reused up to five reaction cycles without losing the catalytic activity.展开更多
We describe here an electro-reforming strategy to upcycle polyethylene terephthalate(PET)waste with simultaneous hydrogen production by a bifunctional nickel-cobalt nitride nanosheets electrocatalyst.PET plastics are ...We describe here an electro-reforming strategy to upcycle polyethylene terephthalate(PET)waste with simultaneous hydrogen production by a bifunctional nickel-cobalt nitride nanosheets electrocatalyst.PET plastics are digested in alkaline solution giving an electrochemically active monomer ethylene glycol(EG).The introduction of Co in Co-Ni3N/carbon cloth(CC)promotes the redox behavior of Ni2+/Ni3+,which is beneficial for EG oxidation at an ultra-low potential(1.15 V vs.reversible hydrogen electrode(RHE))and breaks through the limitation of high catalytic potentials of simple Ni-based electrocatalysts(1.30 V).In PET hydrolysate with Co-Ni3N/CC couples,an integrated EG oxidation-hydrogen production system achieves a current density of 50 mA·cm^(−2)at a cell voltage of 1.46 V,which is 370 mV lower than the conventional water splitting.The in-situ Raman and Fourier transform infrared(FTIR)spectroscopies and density functional theory(DFT)calculations identify the catalytic mechanism and point to advantages of heterostructure engineering in optimizing adsorption energies and promoting catalytic activities for EG oxidation.展开更多
With increasing emphasis on green chemistry,biomass-based materials have attracted increased attention regarding the development of highly efficient functional materials.Herein,a new pore-rich cellulose nanofibril aer...With increasing emphasis on green chemistry,biomass-based materials have attracted increased attention regarding the development of highly efficient functional materials.Herein,a new pore-rich cellulose nanofibril aerogel is utilized as a substrate to integrate highly conductive polypyrrole and active nanoflower-like nickel-cobalt layered double hydroxide through in situ chemical polymerization and electrodeposition.This ternary composite can act as an effective self-supported electrode for the electrocatalytic oxidation of glucose.With the synergistic effect of three heterogeneous components,the electrode achieves outstanding glucose sensing performance,including a high sensitivity(851.4μA·mmol^(−1)·L·cm^(−2)),a short response time(2.2 s),a wide linear range(two stages:0.001−8.145 and 8.145−35.500 mmol·L^(−1)),strong immunity to interference,outstanding intraelectrode and interelectrode reproducibility,a favorable toxicity resistance(Cl^(‒)),and a good long-term stability(maintaining 86.0%of the original value after 30 d).These data are superior to those of some traditional glucose sensors using nonbiomass substrates.When determining the blood glucose level of a human serum,this electrode realizes a high recovery rate of 97.07%–98.89%,validating the potential for highperformance blood glucose sensing.展开更多
Cobalt has excellent electrochemical,magnetic,and heat properties.As a strategic resource,it has been applied in many hightech products.However,the recent rapid growth of the battery industry has substantially deplete...Cobalt has excellent electrochemical,magnetic,and heat properties.As a strategic resource,it has been applied in many hightech products.However,the recent rapid growth of the battery industry has substantially depleted cobalt resources,leading to a crisis of cobalt resource supply.The paper examines cobalt ore reserves and distribution,and the recent development and consumption of cobalt resources are summarized as well.In addition,the principles,advantages and disadvantages,and research status of various methods are discussed comprehensively.It can be concluded that the use of diverse sources(Cu-Co ores,Ni-Co ores,zinc plant residues,and waste cobalt products)for cobalt production should be enhanced to meet developmental requirements.Furthermore,in recovery technology,the pyro-hydrometallurgical process employs pyrometallurgy as the pretreatment to modify the phase structure of cobalt minerals,enhancing its recovery in the hydrometallurgical stage and facilitating high-purity cobalt production.Consequently,it represents a promising technology for future cobalt recovery.Lastly,based on the above conclusions,the prospects for cobalt are assessed regarding cobalt ore processing and sustainable cobalt recycling,for which further study should be conducted.展开更多
基金Project (2005CB623703) supported by the National Basic Research Program of China Project (50474051) supported by the National Natural Science Foundation of China+2 种基金 Project (CX2009B032) supported by Innovation Foundation for Postgraduate of Hunan Province, China Project (ZKJ2008018) supported by the Precious Apparatus Open Share Foundation of Central South University, China Project (2009ybfz02) supported by the Outstanding Doctoral Dissertation Support Foundation of Central South University, China
文摘Ni coating and Ni-Co alloy coatings were produced by adjusting the composition of the plating solution using a direct current electrodepositing process. The oxidation behaviors of nickel and nickel-cobalt alloys in air at 960 ℃ were studied by thermogravimetric （TG） analyzer and then the formed oxide scales were examined by scanning electron microscopy/energy dispersive spectroscopy （SEM/EDS）, X-ray diffractometry （XRD）, and Raman spectroscopy. The scale morphologies, composition, grain size and mechanism of oxidation were discussed in detail. The results show that oxidation rates ofNi, Ni-7%Co （mass fraction） and Ni-15%Co generally follow parabolic relationship, whereas that of Ni-30% Co alloy follows cubic relationship. The higher the Co content of the alloys is, the faster the oxidation rate is. Metal concentration profiles reveal cobalt depletion in the alloy surface beneath oxide scales, and a progressive＇enrichment in cobalt towards the outer surface of the scale.
基金financial support for this work from the Strategic Priority Research Program of CAS(XDB36030000)the National Natural Science Foundation of China(21422303,21573049,21872043,22002028)+3 种基金the National Basic Research Plan of China(2016YFA0201600)the Beijing Natural Science Foundation(2142036)the Youth Innovation Promotion Associationthe Special Program of “One Belt One Road”of CAS。
文摘The hierarchical structure of molybdenum disulfide(MoS2)nanosheet arrays stemmed from nickelcobalt layered double hydroxide(NiCo-LDH)/carbon cloth was prepared by growing the MoS_(2) nanosheet arrays onto the NiCo-LDH template which was pre-deposited onto the carbon cloth substrate.In this electrode configuration,carbon cloth is the three dimensional and conductive skeleton;NiCo-LDH nanosheets,as the template,ensure the oriented growth of MoS2 nanosheet arrays.Therefore,more MoS_(2) active sites are exposed and the catalyst exhibits good hydrogen evolution reaction activity.
文摘1,8-Dioxo-octahydroxanthenes (4a-4f) and 1,8-dioxohexahydroacridines (5a-5c) were synthesized by novel, simple and eco-friendly method with higher yields in the presence of magnetically separable nano nickel-cobalt ferrite catalyst (Ni0.5Co0.5Fe2O4). The former, 1,8-dioxo-octahydroxanthenes have been synthesized from dimedone and different aromatic aldehydes, while the latter from this mixture are along with ammonium acetate. The main advantage of this method is that the nano catalyst can be reused up to five reaction cycles without losing the catalytic activity.
基金supported by the National Natural Science Foundation of China(Nos.22072107 and 21872105)the Science&Technology Commission of Shanghai Municipality(No.19DZ2271500)the Fundamental Research Funds for the Central Universities.
文摘We describe here an electro-reforming strategy to upcycle polyethylene terephthalate(PET)waste with simultaneous hydrogen production by a bifunctional nickel-cobalt nitride nanosheets electrocatalyst.PET plastics are digested in alkaline solution giving an electrochemically active monomer ethylene glycol(EG).The introduction of Co in Co-Ni3N/carbon cloth(CC)promotes the redox behavior of Ni2+/Ni3+,which is beneficial for EG oxidation at an ultra-low potential(1.15 V vs.reversible hydrogen electrode(RHE))and breaks through the limitation of high catalytic potentials of simple Ni-based electrocatalysts(1.30 V).In PET hydrolysate with Co-Ni3N/CC couples,an integrated EG oxidation-hydrogen production system achieves a current density of 50 mA·cm^(−2)at a cell voltage of 1.46 V,which is 370 mV lower than the conventional water splitting.The in-situ Raman and Fourier transform infrared(FTIR)spectroscopies and density functional theory(DFT)calculations identify the catalytic mechanism and point to advantages of heterostructure engineering in optimizing adsorption energies and promoting catalytic activities for EG oxidation.
基金supported by the National Natural Science Foundation of China(Grant No.31901249),the Hunan Provincial Natural Science Foundation of China(Grant No.2022JJ30079)the Hunan Provincial Technical Innovation Platform and Talent Program in Science and Technology(Grant No.2020RC3041)the Training Program for Excellent Young Innovators of Changsha(Grant No.kq2106056).
文摘With increasing emphasis on green chemistry,biomass-based materials have attracted increased attention regarding the development of highly efficient functional materials.Herein,a new pore-rich cellulose nanofibril aerogel is utilized as a substrate to integrate highly conductive polypyrrole and active nanoflower-like nickel-cobalt layered double hydroxide through in situ chemical polymerization and electrodeposition.This ternary composite can act as an effective self-supported electrode for the electrocatalytic oxidation of glucose.With the synergistic effect of three heterogeneous components,the electrode achieves outstanding glucose sensing performance,including a high sensitivity(851.4μA·mmol^(−1)·L·cm^(−2)),a short response time(2.2 s),a wide linear range(two stages:0.001−8.145 and 8.145−35.500 mmol·L^(−1)),strong immunity to interference,outstanding intraelectrode and interelectrode reproducibility,a favorable toxicity resistance(Cl^(‒)),and a good long-term stability(maintaining 86.0%of the original value after 30 d).These data are superior to those of some traditional glucose sensors using nonbiomass substrates.When determining the blood glucose level of a human serum,this electrode realizes a high recovery rate of 97.07%–98.89%,validating the potential for highperformance blood glucose sensing.
基金the financial support of Guangxi Science and Technology Major Project(Guike AA22068078)the Natural Science Foundation of Henan Province(No.222300420548)+2 种基金Henan Province Science and Technology Research and Development plan joint Fund(No.232301420043)the Key Project of the National Key Research and Development Program of China(No.2021YFC2902604)Modern Analysis and Computing Centre in Zhengzhou University。
文摘Cobalt has excellent electrochemical,magnetic,and heat properties.As a strategic resource,it has been applied in many hightech products.However,the recent rapid growth of the battery industry has substantially depleted cobalt resources,leading to a crisis of cobalt resource supply.The paper examines cobalt ore reserves and distribution,and the recent development and consumption of cobalt resources are summarized as well.In addition,the principles,advantages and disadvantages,and research status of various methods are discussed comprehensively.It can be concluded that the use of diverse sources(Cu-Co ores,Ni-Co ores,zinc plant residues,and waste cobalt products)for cobalt production should be enhanced to meet developmental requirements.Furthermore,in recovery technology,the pyro-hydrometallurgical process employs pyrometallurgy as the pretreatment to modify the phase structure of cobalt minerals,enhancing its recovery in the hydrometallurgical stage and facilitating high-purity cobalt production.Consequently,it represents a promising technology for future cobalt recovery.Lastly,based on the above conclusions,the prospects for cobalt are assessed regarding cobalt ore processing and sustainable cobalt recycling,for which further study should be conducted.
基金supported by the National Natural Science Foundation of China (No. U2033204)Engineering Laboratory of Battery Safety and Accident Control of Petroleum and Chemical Industry, China (No. ELBSAC202304)supported by Youth Innovation Promotion Association, Chinese Academy of Sciences (No. Y201768)
