p-Cu<sub>2</sub>O/n-TiO<sub>2</sub>纳米管复合电极的制备及其光电性能

摘要

采用二次阳极氧化法制备结构规整的TiO₂纳米管阵列，进一步采用恒电流电化学沉积Cu₂O制备纳米管阵列异质结复合电极Cu₂O/TiO₂。采用扫描电镜（SEM）、X射线衍射（XRD）、X射线光电子能谱（XPS）、紫外-可见漫反射光谱（UV-vis DRS）等对样品进行表征。SEM结果表明TiO₂纳米管垂直排列在基底Ti上，管径约为50 nm，管长约为1 μm左右，Cu₂O以颗粒状均匀地沉积在TiO₂纳米管阵列上；XRD结果表明TiO₂为锐钛矿晶型，而沉积的Cu₂O为立方型；XPS结果表明Cu₂O/TiO₂中Cu和Ti分别以Cu¹⁺和Ti²⁺的形式存在；UV-vis DRS结果表明沉积Cu₂O的电极材料的吸光范围由紫外区扩展到紫外-可见区。光电性能测试结果表明：制备的Cu₂O/TiO₂复合电极具有良好的光电分解水的活性，其光电流密度是TiO₂电极的2倍以上。Cu₂O沉积量为5.18×10^-7 mol时，Cu₂O/TiO₂的光转化效率可达0.41%（0.735 V vs. RHE）。采用焙烧方法改善Cu₂O/TiO₂电极性能，在373 K下空气中焙烧0.5 h，电极的光转化效率可达0.65%（0.759 V vs. RHE）。最后考察了CT-0.1-373和CT-0.1电极的稳定性，经连续100次线性伏安（LSV）扫描，CT-0.1-373的光转化效率为0.64%（0.762 V vs. RHE），而未经焙烧处理的CT-0.1电极，经100次LSV扫描光转化效率值降低至0.38%（0.767 V vs. RHE），结果表明低温焙烧处理不仅可显著提高Cu₂O/TiO₂复合电极的光电活性，也可改善其稳定性。

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	张立博
	王华
	韩金玉

关键词： TiO₂纳米管阵列； Cu₂O/TiO₂异质结复合电极；焙烧；光电性能

Abstract：

A two-step electrochemical anodization method was used to fabricate the TiO₂ nanotube electrode, and Cu₂O was deposited onto the annealed TiO₂ nanotubes arrays via the galvanostatic electrodeposition method. Scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV-vis diffuse reflectance spectra (UV-vis DRS) were used to identify the characterization of the samples. The SEM results show that TiO₂ nanotubes align vertically on the Ti substrate with an average tube diameter of 50 nm and a tube length of approximately 1 μm. The Cu₂O nanoparticles are uniformly deposited on the TiO₂ nanotubes arrays. The XRD results show that the structures of TiO₂ and Cu₂O are anatase and cubic, respectively. XPS results reveal the existence states of Cu and Ti in Cu₂O/TiO₂ are Cu¹⁺ and Ti²⁺, correspondingly. UV-vis DRS results reveal the deposited Cu₂O expands the ability of light absorption to the visible area. Photoelectrochemical (PEC) tests reveal that fabricated Cu₂O/TiO₂ shows better activity and the photocurrent density of the Cu₂O/TiO₂ is more than 2 times compared with those of the TiO₂ nanotubes. The photoconversion efficiency of the Cu₂O/TiO₂ reaches 0.41% at 0.735 V (vs. RHE) when the deposition amount of Cu₂O is 5.18×10^-7 mol. The Cu₂O/TiO₂ was annealed to enhance the performance. By annealing at 373 K for 0.5 h in air, the photoconversion efficiency of the annealed sample is up to 0.65% (0.759 V vs. RHE). The stability of the CT-0.1 and CT-0.1-373 was investigated at last. The test of continuous linear sweep voltammetry (LSV) of 100 times reveal that CT-0.1-373 remains a photoconversion efficiency of 0.64% (0.762 V vs. RHE) after 100 scans, while CT-0.1 remains a photoconversion efficiency of 0.38%, which reveals annealing at low temperatures not only improves the activity but also enhances the stability of the Cu₂O/TiO₂.

Keywords： TiO₂ nanotubes； Cu₂O/TiO₂ heterojunction composite electrode； annealing； photoelectrochemical performance

Received 2016-03-16;

Fund:

国家自然科学基金（21206117）。

Corresponding Authors: 王华,E-mail:tjuwanghua@tju.edu.com. Email: tjuwanghua@tju.edu.com

About author: 张立博(1990-),女,硕士研究生,现从事电化学方面的研究.

引用本文:

张立博, 王华, 韩金玉.p-Cu₂O/n-TiO₂纳米管复合电极的制备及其光电性能[J]. 化学工业与工程, 2017,34(5): 11-18

Zhang Libo, Wang Hua, Han Jinyu.Preparation and Photoelectrochemical Characterization of p-Cu₂O/n-TiO₂ Nanotubes[J]. Chemcial Industry and Engineering, 2017,34(5): 11-18

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