Rational designs of electrocatalytic active sites and architectures are of great importance to develop cost-efficient non-noble metal electrocatalysts towards efficient oxygen reduction reaction(ORR)for high-performan...Rational designs of electrocatalytic active sites and architectures are of great importance to develop cost-efficient non-noble metal electrocatalysts towards efficient oxygen reduction reaction(ORR)for high-performance energy conversion and storage devices.In this work,active amorphous Fe-based nanoclusters(Fe NC)are elaborately embedded at the inner surface of balloonlike N-doped hollow carbon(Fe NC/Csphere)as an efficient ORR electrocatalyst with an ultrathin wall of about 10 nm.When evaluated for electrochemical performance,Fe NC/Csphere exhibits decent ORR activity with a diffusionlimited current density of~5.0 mA/cm^(2)and a half-wave potential of~0.81 V in alkaline solution,which is comparable with commercial Pt/C and superior to Fe nanoparticles supported on carbon sheet(Fe NP/C sheet)counterpart.The electrochemical analyses combined with electronic structure characterizations reveal that robust Fe-N interactions in amorphous Fe nanoclusters are helpful for the adsorption of surface oxygen-relative species,and the strong support effect of N-doped hollow carbon is benefitial for accelerating the interfacial electron transfer,which jointly contributes to improve ORR kinetics for Fe NC/Csphere.展开更多
ZnO-Au_(25) nanocomposites were synthesized by doping Au_(25) nanoclusters into the porous Zn O nanospheres. It was notable that the ultrasmall Au_(25) nanoclusters possessed uniform sizes and fine dispersibility on t...ZnO-Au_(25) nanocomposites were synthesized by doping Au_(25) nanoclusters into the porous Zn O nanospheres. It was notable that the ultrasmall Au_(25) nanoclusters possessed uniform sizes and fine dispersibility on the porous ZnO supports. A considerable correlation between the loading of Au_(25) nanoclusters and the photocatalytic activity was found. Compared with the pure ZnO nanospheres, the ZnO-Au_(25) nanocomposites exhibited more efficient photocatalytic activity in terms of degradation of Rhodamine B(RhB) in an aqueous solution. In addition, the possible photocatalytic mechanisms are discussed in this work. This strategy may be helpful for preparing other novel hybrid nanocomposites with well-defined structures and superior performances.展开更多
基金supported by the National Natural Science Foundation of China(No.U1632161)the Scientific Research Start-up Fund for Introduction of High-level Talents of HFNU in 2020(No.2020rcjj03)+1 种基金the Anhui Provincial College Students Innovation and Entrepreneurship Plan Project in 2020(No.S202014098170)the Anhui Provincial Natural Science Foundation(No.1708085MA21,No.1808085JQ13,No.2008085MF217)。
文摘Rational designs of electrocatalytic active sites and architectures are of great importance to develop cost-efficient non-noble metal electrocatalysts towards efficient oxygen reduction reaction(ORR)for high-performance energy conversion and storage devices.In this work,active amorphous Fe-based nanoclusters(Fe NC)are elaborately embedded at the inner surface of balloonlike N-doped hollow carbon(Fe NC/Csphere)as an efficient ORR electrocatalyst with an ultrathin wall of about 10 nm.When evaluated for electrochemical performance,Fe NC/Csphere exhibits decent ORR activity with a diffusionlimited current density of~5.0 mA/cm^(2)and a half-wave potential of~0.81 V in alkaline solution,which is comparable with commercial Pt/C and superior to Fe nanoparticles supported on carbon sheet(Fe NP/C sheet)counterpart.The electrochemical analyses combined with electronic structure characterizations reveal that robust Fe-N interactions in amorphous Fe nanoclusters are helpful for the adsorption of surface oxygen-relative species,and the strong support effect of N-doped hollow carbon is benefitial for accelerating the interfacial electron transfer,which jointly contributes to improve ORR kinetics for Fe NC/Csphere.
基金the National Natural Science Foundation of China (51472001, 21201001, 21571001)Anhui Provincial Natural Science Foundation (1208085QB25)+2 种基金the Ph.D. Start-up Fundthe Youth Back-bone Program of Anhui Universitythe 211 Project of Anhui University
文摘ZnO-Au_(25) nanocomposites were synthesized by doping Au_(25) nanoclusters into the porous Zn O nanospheres. It was notable that the ultrasmall Au_(25) nanoclusters possessed uniform sizes and fine dispersibility on the porous ZnO supports. A considerable correlation between the loading of Au_(25) nanoclusters and the photocatalytic activity was found. Compared with the pure ZnO nanospheres, the ZnO-Au_(25) nanocomposites exhibited more efficient photocatalytic activity in terms of degradation of Rhodamine B(RhB) in an aqueous solution. In addition, the possible photocatalytic mechanisms are discussed in this work. This strategy may be helpful for preparing other novel hybrid nanocomposites with well-defined structures and superior performances.
