The development of efficient catalytic electrode toward oxygen reduction reaction(ORR)is still a great challenge for the wide use of zinc–air batteries.Herein,Co_(2)N nanoparticles(NPs)anchored on N-doped carbon from...The development of efficient catalytic electrode toward oxygen reduction reaction(ORR)is still a great challenge for the wide use of zinc–air batteries.Herein,Co_(2)N nanoparticles(NPs)anchored on N-doped carbon from cattail were verified with excellent catalytic performances for ORR.The onset and half-wave potentials over the optimal catalyst reach to 0.96 V and 0.84 V,respectively.Current retention rates of 96.8%after 22-h test and 98.8%after running 1600 s were obtained in 1 M methanol solution.Density functional theory simulation proposes an apparently increased electronic states of Co_(2)N in N-doped carbon layer close to the Fermi level.Higher charge density,favorable adsorption,and charge transfer of intermediates originate from the coexistence of Co_(2)N NPs and N atoms in carbon skeleton.The superior catalytic activity of composites also was confirmed in zinc–air batteries.This novel catalytic property and controllable preparation approach of Co_(2)Ncarbon composites provide a promising avenue to fabricate metal-containing catalytically active carbon from biomass.展开更多
Pressure-related sensing materials in mechanochromic luminescent materials have received wide attention.However,at present,most piezochromic luminescence(PCL)materials have problems such as aggregation-caused quenchin...Pressure-related sensing materials in mechanochromic luminescent materials have received wide attention.However,at present,most piezochromic luminescence(PCL)materials have problems such as aggregation-caused quenching(ACQ)effect due to the presence of powder form,complicated preparation methods and fluorescence quenching effect under high pressure.To solve these problems,we employ three components containing carbon dots(CDs),layered double hydroxides(LDHs)and polyvinyl alcohol(PVA)to construct the CDs-LDHs/PVA film.The LDHs can provide a rigid environment for CDs and improve the luminescent efficiency of CDs.The film shows high sensitivity,stability and reversibility.Moreover,the compressed film can recover to its original state by heating.Therefore,the PCL film with dual emission(fluorescence and phosphorescence)characteristic is constructed,which boosts the sensitivity of pressure-sensing.展开更多
基金Financial supports from the National Natural Science Foundation of China(no.31901272,no.22075254)the Jiangsu Province Key Laboratory of Biomass Energy and Materials(no.JSBEM-S-201906)。
文摘The development of efficient catalytic electrode toward oxygen reduction reaction(ORR)is still a great challenge for the wide use of zinc–air batteries.Herein,Co_(2)N nanoparticles(NPs)anchored on N-doped carbon from cattail were verified with excellent catalytic performances for ORR.The onset and half-wave potentials over the optimal catalyst reach to 0.96 V and 0.84 V,respectively.Current retention rates of 96.8%after 22-h test and 98.8%after running 1600 s were obtained in 1 M methanol solution.Density functional theory simulation proposes an apparently increased electronic states of Co_(2)N in N-doped carbon layer close to the Fermi level.Higher charge density,favorable adsorption,and charge transfer of intermediates originate from the coexistence of Co_(2)N NPs and N atoms in carbon skeleton.The superior catalytic activity of composites also was confirmed in zinc–air batteries.This novel catalytic property and controllable preparation approach of Co_(2)Ncarbon composites provide a promising avenue to fabricate metal-containing catalytically active carbon from biomass.
基金supported by the National Key R&D Program of China(No.2019YFC1906100)the National Natural Science Foundation of China(Nos.21571014 and 21521005)+2 种基金the Beijing Municipal Natural Science Foundation(No.2172044)the Open Research Fund Program of Key Laboratory of Cosmetic,China National Light Industry,Beijing Technology and Business University(No.KLC-2019-ZD1)the Fundamental Research Funds for the Central Universities(No.12060093063)。
文摘Pressure-related sensing materials in mechanochromic luminescent materials have received wide attention.However,at present,most piezochromic luminescence(PCL)materials have problems such as aggregation-caused quenching(ACQ)effect due to the presence of powder form,complicated preparation methods and fluorescence quenching effect under high pressure.To solve these problems,we employ three components containing carbon dots(CDs),layered double hydroxides(LDHs)and polyvinyl alcohol(PVA)to construct the CDs-LDHs/PVA film.The LDHs can provide a rigid environment for CDs and improve the luminescent efficiency of CDs.The film shows high sensitivity,stability and reversibility.Moreover,the compressed film can recover to its original state by heating.Therefore,the PCL film with dual emission(fluorescence and phosphorescence)characteristic is constructed,which boosts the sensitivity of pressure-sensing.
