Hierarchical ZnO nanorod electrodes: Effect of post annealing on structural and photoelectrochemical performance

• Published in: Materials letters 2013-02, Vol.93, p.333-336
• Main Authors: Bhatti, Ijaz Ahmad, Nirmal Peiris, T.A., Smith, Thomas D., Upul Wijayantha, K.G.
• Format: Article
• Language: English
• Subjects: Annealing; crystal structure; deformation; electrodes; fluorine; glass; Microwave; microwave radiation; Nanorods; Photoelectrochemical; surface area; tin; X-ray diffraction; zinc oxide; ZnO
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2012.11.100

The effect of microwave and conventional annealing has been studied on ZnO nanorods grown on fluorine doped tin oxide (FTO) glass substrates by chemical bath deposition. XRD diffractograms revealed that there is a difference in the film crystallinity. FEG-SEM images of microwave irradiated ZnO nanorods indicate that microwave radiation caused sintering between individual rods and bundling them up thereby creating new rods with large diameter, without significantly affecting the hierarchical rod structures. It shows that internal surface area of treated films decreased compared to that of as-deposited film. The photoelectrochemical characteristics showed a decrease in the current density of the treated films compared to that of as-deposited film. The reduction of the photocurrent corresponding to conventional radiant annealed ZnO electrodes is more pronounce presumably due to deformation of rod structure and poor charge transport. ► The article describes the post annealing effect of ZnO nanorods. ► The conventional radiant annealing deformed the nanorods than the microwave treatment.. ► Microwave and conventional post annealing reduces the photocurrent compared to the as-deposited. ► This is due to the poor charge transport in the deformed electrodes.