화학공학소재연구정보센터
International Journal of Hydrogen Energy, Vol.37, No.1, 854-859, 2012
A photoelectrochemical investigation of the hydrogen-evolving doped TiO2 nanotube arrays electrode
The present work investigates the photoelectrochemical behavior of nanotubular N/C-TiO2 electrode for hydrogen production. Via the sonoelectrochemical anodization process of 1 h, N-containing TiO2 based nanotube arrays(N-TNT) with the length of about 650 nm were fabricated in fluoride aqueous solution added 0.25 M NH4NO3; C-containing TiO2 based nanotube arrays(C-TNT) with the length of about 2 mu m were prepared in fluoride ethylene glycol solution. In virtue of the longer tubes with the larger surface areas, C-TNT can harvest more light and produce more photoactive sites than N-TNT, which also made the charge transfer resistance in C-TNT larger than that in N-TNT. Considered the more negative flat band potential of C-TNT, C-TNT has the smaller energy barrier and the better photoelectrochemical activity. It may be attributed to the appropriate defect concentration gradient owing to the modification of C element. Under UV-vis light (320-780 nm) irradiation, the average hydrogen generation rate of C-TNT was 282 mu L h(-1) cm(-2). The surface properties and near-surface properties of the resultant electrode were synthetically analyzed by using UV-vis diffuse reflectance spectra(DRS), field emission scanning electron microscopy (FESEM), I-t curves, and electrochemical impedance spectroscopy (EIS) techniques. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.