title: Synthesis of Hierarchical Nanoporous Microstructures via the Kirkendall Effect in Chemical Reduction Process.
abstract: A series of novel hierarchical nanoporous microstructures have been synthesized through one-step chemical reduction of micron size Cu2O and Co3O4 particles. By controlling the reduction time, non-porous Cu2O microcubes sequentially transform to nanoporous Cu/Cu2O/Cu dented cubic composites and hollow eightling-like Cu microparticles. The mechanism involved in the complex structural evolution is explained based on oxygen diffusion and Kirkendall effect. The nanoporous Cu/Cu2O/Cu dented cubic composites exhibit superior electrochemical performance as compared to solid Cu2O microcubes. The reduction of nonporous Co3O4 also exhibits a uniform sequential reduction process from nonporous Co3O4 to porous Co3O4/CoO composites, porous CoO, porous CoO/Co composites, and porous foam-like Co particles. Nanoscale channels originate from the particle surface and eventually develop inside the entire product, resulting in porous foam-like Co microparticles. The Kirkendall effect is believed to facilitate the formation of porous structures in both processes.
authors.affiliation: State Key Laboratory of Material-Oriented Chemical Engineering, Nanjing Tech University (Former Name: Nanjing University of Technology), Jiangsu, Nanjing 210009, P.R. China.
authors.forename: Ling
authors.initials: L
authors.lastname: Gao
authors.affiliation: State Key Laboratory of Material-Oriented Chemical Engineering, Nanjing Tech University (Former Name: Nanjing University of Technology), Jiangsu, Nanjing 210009, P.R. China.
authors.forename: Chao
authors.initials: C
authors.lastname: Pang
authors.affiliation: State Key Laboratory of Material-Oriented Chemical Engineering, Nanjing Tech University (Former Name: Nanjing University of Technology), Jiangsu, Nanjing 210009, P.R. China.
authors.forename: Dafang
authors.initials: D
authors.lastname: He
authors.affiliation: State Key Laboratory of Material-Oriented Chemical Engineering, Nanjing Tech University (Former Name: Nanjing University of Technology), Jiangsu, Nanjing 210009, P.R. China.
authors.forename: Liming
authors.initials: L
authors.lastname: Shen
authors.affiliation: Center for Materials for Information Technology (MINT), The University of Alabama, Tuscaloosa, AL 35487, USA.
authors.forename: Arunava
authors.initials: A
authors.lastname: Gupta
authors.affiliation: State Key Laboratory of Material-Oriented Chemical Engineering, Nanjing Tech University (Former Name: Nanjing University of Technology), Jiangsu, Nanjing 210009, P.R. China.
authors.forename: Ningzhong
authors.initials: N
authors.lastname: Bao