Volume No. 13 Issue No.: 02 Page No.: 92-96 October-December 2018

 

TAILORING THE BAND GAP OF NANOROD PHOTO ANODE MATERIAL FOR HYDROGEN PRODUC -TION BY SOLAR WATER SPLITTING

 

Ndlangamandla C. L. 1, Bharuth-Ram K.*2 and Maaza M.3

1. Physics Department, Durban University of Technology, Durban, (SOUTH AFRICA)
2. Department of Physics and Engineering, University of Zululand, (SOUTH AFRICA)
3. Materials Research Division, iThemba LABS, P.O. Box 722, Somerset West, (SOUTH AFRICA)

 

Received on : July 13, 2018

 

ABSTRACT

 

In order to address the environmental impact of fossil fuels, alternatives under consideration include an energy economy based on the extraction of hydrogen from utilising solar radiation to split water in a photoelectrochemical (PEC) cell. A photoanode material with an electronic band gap suitable for efficient absorption of visible light in a PEC cell is hematite (?-Fe2O3) whose earth abundance and chemically stability has driven the search for low cost synthesis and refinement of its band gap for applications in an efficient, cost-effective solar energy economy. In our search, we have utilized the aqueous chemical method to grow thin films of hematite on fluorine doped tin oxide glass substrates. The films were doped with different concentrations of ruthenium in order to control the band gap of the hematite films. Heat treatment of the films at 500oC resulted in their morphing into hematite nanorods (NRs). The formation of the hematite NRs was confirmed with X-ray diffraction and Mössbauer spectroscopy (MS), while the band gap was estimated from UV-Vis optical absorption measurements. The band gap was found to be directly related to the Ru dopant concentration and in the range well suited to drive the water splitting process in a PEC cell.

 

Keywords : Hematite, Band gap, Water splitting, Hydrogen generation

 

 

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