三维ZnO/CuO纳米树的制备及其光电化学性能的研究

Fabrication of 3D ZnO/CuO Nanotrees and Investigation of Their Photoelectrochemical Properties

采用简单的热氧化法和水热生长法,在泡沫铜上成功制备了三维ZnO/CuO纳米树（3D ZnO/CuO NTs）阵列。利用扫描电镜（SEM）、电子能谱（EDS）和透射电镜（TEM）对3D ZnO/CuO NTs的形貌,成分以及结构进行了表征。结果表明：3D ZnO/CuO NTs是由CuO纳米线（CuO NWs,双晶结构）主干和ZnO纳米线（ZnO NWs,单晶结构）分枝构成的。通过调整ZnONWs的生长时间,得到不同形貌的3D ZnO/CuO NTs,并对其生长机制进行了分析。重点研究了3D ZnO/CuO NTs电极的光电化学性能,包括光电流密度,光稳定性和光生载流子分离/复合的过程。结果表明：随着ZnO NWs生长时间t增加,电极的光电化学性能增加,当t过长,反而下降。本研究中ZnO NWs生长的最佳时间为30 min,3D ZnO/CuONTs电极的光电流密度高达-2.78 mA·cm^-2（-0.5 V vs Ag/AgCl RE）。相比单一的CuO NWs电极,光电流密度增加了38%。并且表现出相对较好的光稳定性,具有优良的光电转换性质。这些成果显示了在泡沫铜上制备的3D ZnO/CuO NTs具有优异的光电化学性能,在光阴极材料方面具有很好的应用潜力。

3-Dimentional ZnO/CuO nanotrees(3D ZnO/CuO NTs） arrays on copper foam were successfully fabricated by using simple thermal oxidation and hydrothermal growth methods. Morphology,composition and structure of the 3D ZnO/CuO NTs were characterized by scanning electron microscopy(SEM）,X-ray photoelectron spectroscopy(XPS） and transmission electron microscopy(TEM）. The results showed that 3D ZnO/CuO NTs were composed of CuO nanowires(CuO NWs,bicrystalline structure） as backbone and ZnO nanowires(ZnO NWs,single crystal structure） as branches. 3D ZnO/CuO NTs with different morphologies were prepared by adjusting the growth time(t） of ZnO NWs,and its growth mechanism was also analyzed. The photoelectrochemical(PEC）measurements of the 3D ZnO/CuO NTs as electrodes were importantly studied,including photocurrent density,photostability and photogenerated charge transfer/recombination processes. The PEC performance of the electrodes improved with the increasing t,but dropped when t was too long. Herein,the photocurrent density of the 3D ZnOt/CuO NTs(t = 30 min） reached up to-2. 78 mA·cm^-2（-0. 5 V vs Ag/Ag Cl RE）,which had an increase of 38% than that of the bare CuO NWs electrodes. It exhibited relatively good light stability and excellent photoelectric conversion properties. These achieved results showed that 3D ZnO/CuO NTs photoelectrode on copper foam had good PEC properties,which had a good application potential in the field of photocathode materials.