Highly oriented hematite nanorods arrays for photoelectrochemical water splitting
Highly oriented hematite nanorods arrays for photoelectrochemical water splitting
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DOI：
10.1016/j.jpowsour.2012.01.093
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发表时间：
2012-05-01
影响因子：
9.2
通讯作者：
Souza, Flavio L.
中科院分区：
文献类型：
--
作者：
de Carvalho, Vitor A. N.;Luz, Roberto A. de S.;Souza, Flavio L.
本文报道了一种在低温、短反应时间下通过单一化学路线合成的取向性赤铁矿非掺杂光阳极。用赤铁矿纳米棒（厚度为450 nm）修饰的氟掺杂氧化锡（FTO）电极在0.4 V（相对于Ag/AgCl）下显示出0.9 mA cm（-2）的光电流。此外，我们在黑暗条件下进行了电化学表征，以了解光阳极的催化性能。基于循环伏安法的结果，我们提出了一个新的机制来解释分子氧的演变到定向赤铁矿表面，这是不一致的，从Pourbaix图提取的参数。OH-和铁氧化物之间的化学相互作用从表面表明，化学反应首先由电极/电解质界面上的羟基氧化物。换句话说，分子氧的析出之前是形成羟基-羟基，这是一个缓慢且可能限制的步骤。(C)2012爱思唯尔有限公司版权所有。
We report an oriented hematite undoped photanode synthesized by single chemical route step at low temperature and with a short reaction time. Fluorine-doped tin oxide (FTO) electrodes modified with hematite nanorod (450 nm of thickness) showed a photocurrent with 0.9 mA cm(-2) at 0.4 V vs Ag/AgCl. Also, we have done electrochemical characterizations under dark conditions in order to understand the catalytic properties of the photoanode. Based on cyclic voltammetry results we have proposed a new mechanism to explain the evolution of molecular oxygen onto oriented hematite surfaces, in which is not inconsistent with thermodynamical parameters extracted from the Pourbaix diagram. A chemical interaction between OH- and iron oxide from the surface suggested that the chemical reaction is first governed by oxy-hydroxides on the electrode/electrolyte interface. In other word, molecular oxygen evolution is preceded by the formation of oxy-hydroxide groups, a slow and possibly limiting step. (C) 2012 Elsevier B.V. All rights reserved.