Nano Express

Nanoscale Research Letters

, Volume 4, Issue 10, pp 1183-1190

Open Access This content is freely available online to anyone, anywhere at any time.

The Modulation of Optical Property and its Correlation with Microstructures of ZnO Nanowires

  • Haohua LiAffiliated withSchool of Chemistry and Chemical Engineering, Sun Yat-Sen UniversityMOE of Key Laboratory of Bioinorganic and Synthetic Chemistry, Sun Yat-Sen UniversityInstitute of Optoelectronic and Functional Composite Materials, Sun Yat-Sen University
  • , Chaolun LiangAffiliated withInstrumental Analysis & Research Center, Sun Yat-Sen University
  • , Kuan ZhongAffiliated withSchool of Chemistry and Chemical Engineering, Sun Yat-Sen UniversityMOE of Key Laboratory of Bioinorganic and Synthetic Chemistry, Sun Yat-Sen UniversityInstitute of Optoelectronic and Functional Composite Materials, Sun Yat-Sen University
  • , Meng LiuAffiliated withSchool of Chemistry and Chemical Engineering, Sun Yat-Sen UniversityMOE of Key Laboratory of Bioinorganic and Synthetic Chemistry, Sun Yat-Sen UniversityInstitute of Optoelectronic and Functional Composite Materials, Sun Yat-Sen University
  • , Greg A. HopeAffiliated withSchool of Science, Griffith University
  • , Yexiang TongAffiliated withSchool of Chemistry and Chemical Engineering, Sun Yat-Sen UniversityMOE of Key Laboratory of Bioinorganic and Synthetic Chemistry, Sun Yat-Sen UniversityInstitute of Optoelectronic and Functional Composite Materials, Sun Yat-Sen University Email author 
  • , Peng LiuAffiliated withSchool of Chemistry and Chemical Engineering, Sun Yat-Sen UniversityMOE of Key Laboratory of Bioinorganic and Synthetic Chemistry, Sun Yat-Sen UniversityInstitute of Optoelectronic and Functional Composite Materials, Sun Yat-Sen University Email author 

Abstract

ZnO nanowires with both good crystallinity and oxygen vacancies defects were synthesized by thermal oxidation of Zn substrate pretreated in concentrated sulfuric acid under the air atmosphere, Ar- and air-mixed gas stream. The photoluminescence spectra reveal that only near-band-edge (NBE) emission peak was observed for the sample grown in the air atmosphere; the broad blue–green and the red-shifted NBE emission peaks were observed for the sample grown in the mixed gas stream, indicating that the sample grown in the mixed gas stream has a defective structure and its optical properties can be modulated by controlling its structure. The high-resolution transmission electron microscope and the corresponding structural simulation confirm that the oxygen vacancies exist in the crystal of the nanowires grown in the mixed gas stream. The ZnO nanowires with oxygen vacancies defects exhibit better photocatalytic activity than the nanowires with good crystallinity. The photocatalytic process obeys the rules of first-order kinetic reaction, and the rate constants were calculated.

Keywords

ZnO nanowires Thermal oxidation Oxygen vacancies Photoluminescence Photocatalysis