Optimizing Height and Packing Density of Oriented One-Dimensional Photocatalysts for Efficient Water Photoelectrolysis

by Zhou, Huajun; Deng, Huixu; Ghetmiri, Seyed Amir; Abu-Safe, Husam Hamza; Yu, Shui Q.; Yang, Xiaodong; Tian, Z. Ryan

Dependences of water-photoelectrolysis efficiency on heights and packing densities of vertically arrayed ZnO nanorods (NRs) and ZnO microrods (MRs) were systematically studied for the first time over a wide range of light incidence angles, under the direction of nanooptics simulation. In the photoelectrolysis, dense NRs of 1.8 mu m in height afforded the highest photocatalytic efficiencies, and further increases of the height kept lowering down the photocatalytic efficiencies, while sparse MRs taller in height consistently afforded better electrolyte penetration and higher photocurrent densities especially at higher angles of incident light. The experimental results are in line with the nanooptics simulation. This new finding is generally applicable to advancing solar-energy conversions, optics, and optoelectronics using oriented one-dimensional micro/nanocrystallites.

Journal
Journal of Physical Chemistry C
Volume
117
Issue
40
Year
2013
Start Page
20778
ISBN/ISSN
1932-7455; 1932-7447
DOI
10.1021/jp407317k