Acta Phys. -Chim. Sin. ›› 2015, Vol. 31 ›› Issue (4): 783-792.doi: 10.3866/PKU.WHXB201502062

• CATALYSIS AND SURFACE SCIENCE • Previous Articles     Next Articles

Syntheses of ZnO Nano-Arrays and Spike-Shaped CuO/ZnO Heterostructure

LI Xiang-Qi1, FAN Qing-Fei1, LI Guang-Li1, HUANG Yao-Han1, GAO Zhao1, FAN Xi-Mei1, ZHANG Chao-Liang2, ZHOU Zuo-Wan1   

  1. 1 Key Laboratory of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, P. R. China;
    2 State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610031, P. R. China
  • Received:2014-12-15 Revised:2015-02-04 Published:2015-04-03
  • Contact: FAN Xi-Mei E-mail:xmfan@home.swjtu.edu.cn
  • Supported by:

    The project was supported by the High-Tech Research and Development Program of China (2009AA03Z427).

Abstract:

A low-temperature hydrothermal route was applied to fabricate ZnO nano-arrays on fluorinated tin oxide (FTO)-coated glass substrates. The effects of the molar ratios of the precursor concentrations on the ZnO nano-arrays were studied with respect to morphology, optical properties, and growth mechanism. The results show that the length reduced with the increased molar ratios of precursor concentrations, and the diameter first increased then decreased. In general, the change of optical band gap followed the same trend as that for the change in diameter. When the molar ratio of precursor concentrations is 5:5, the optical band gap is 3.2 eV, which is similar to the theoretical value at room temperature. We propose that the optimal molar ratio of zinc nitrate (Zn(NO3)2) to hexamethylenetetramine (HMT, C6H12N4) is 5:5 for the preparation of ZnO nano-arrays. Spike-shaped CuO/ZnO nano-arrays were also successfully synthesized using a two-step solution-system method. Field emission scanning electron microscope (FE-SEM) results show that there were a large number of copper oxide (CuO) nano-particles (NPs) deposited onto the ZnO nano-array surfaces to form spike-shaped structures. The covered CuO NPs exhibited improved photocatalytic properties over pure ZnO nano-arrays under UV irradiation, and the possible photocatalytic mechanism of the CuO/ZnO nano-heterojunction was discussed in detail.

Key words: ZnO nano-array, CuO/ZnO heterostructure, Hydrothermal method, Optical property, Molar ratio

MSC2000: 

  • O645