Hematite Nanorods

Considering there are no grain boundaries present in the material, the quite low photoresponse may be due to i) intrinsic recombinations centers located in mid bandgap states or ii) slow interfacial kinetics at the nanostructured semiconductor/electrolyte interface. 

The same result was obtained in a three-electrode set-up and purging the electrolyte in the 3-electrode vessel with N2 or bubbling with 02 did not affect the results. 

It was concluded that by combining a hematite nanorod electrode with a suitable water oxidation catalysts, for instance platinum or ruthenium dioxide, the photoelectrochemical activity for direct water splitting applications should increase by a factor of 20. 

The promising initial study of hematite nanorod initiated a study of hematite nanorods for the aim of water oxidation [29]. IPCEse and IPCEee in a three-electrode set-up were determined at 350 nm to 2.3 % and 1.0 %, respectively. The fact that IPCEse is twice the IPCEee reveals that the collection of the photogenerated electrons across the hematite film is poor. Nevertheless, the ratio in the quoted investigation [29] is significantly smaller compared to the nanosized isotropic random walk hematite particle system reported by Bjbrksten et al [44]. The photocurrent density at an intensity of 1 sun was in the (xA/cm2 scale in 0.1 M NaOH. 

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Lindgren, T., Wang, H.L., Beermann, N., Vayssieres, L., Hagfeldt, A., Lindquist, S.E. Aqueous photoelectrochemistry of hematite nanorod array. Sol. Energy Mater. Sol. Cells 71, 231 (2002)... 

Chen, M., Jiang, J., Zhou, X. and Diao, G. (2008) Preparation of akaganeite nanorods and their transformation tosphere shape hematite. Journal for Nanoscience and Nanotechnology, 8, 3942-3948. 

Beermann N, Vayssieres L, Lindquist SE, Hagfeldt A (2000) Phtotelectrochemical studies of oriented nanorod thin film of hematite. J Electrochem Soc 147 2456-2461... 

Bicrystalline nanowires of hematite (a-Fe,03) have been synthesized by the oxidation of pure Fe.207 Single-crystalline hexagonal u-Fe20, nanorods and nanobeits can be prepared by a simple iron-water reaction at 673 K.20 Mesoporous quasi-single crystalline... 

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