Photoelectrocatalytic Degradation of Methylene Blue Using ZnO Nanorods Fabricated on Silicon Substrates.
Photoelectrocatalytic Degradation of Methylene Blue Using ZnO Nanorods Fabricated on Silicon Substrates.
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DOI：
10.1166/jnn.2020.16961
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发表时间：
2020-02
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通讯作者：
Ana Paula Rosa;R. P. Cavalcante;Thalita Ferreira da Silva;Fábio Gozzi;C. Byrne;E. McGlynn;G. Casagrande;S. C. D. Oliveira;A. M. Junior
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作者：
Ana Paula Rosa;R. P. Cavalcante;Thalita Ferreira da Silva;Fábio Gozzi;C. Byrne;E. McGlynn;G. Casagrande;S. C. D. Oliveira;A. M. Junior
通过两种技术在硅（Si）衬底上生长ZnO纳米棒：（i）化学浴沉积（CBD）和（ii）结合碳热还原气相传输（CTR-VPT）的CBD种子层。采用扫描电子显微镜（SEM）、X射线衍射（XRD）、X射线光电子能谱（XPS）和接触角测试等手段对ZnO纳米棒进行了表征。采用线性伏安法研究了ZnO纳米棒在UV-ABC光激发下的光电化学性质。使用ZnO纳米棒样品作为光阳极，通过光电催化（PEC）技术施加0.6 V的电势（E）来研究作为代表性有机化合物的亚甲基蓝（MB）的去除。为了比较的目的，在相同的条件下使用光催化（PC）、直接光解和使用纯Si（支撑材料）样品作为PEC中的工作电极来进行实验。通过这两种方法制备的ZnO的XRD分析表明，预期的ZnO纤锌矿相和优选的c轴取向的纳米棒的生长。XPS和接触角测试结果表明，CBD法制备的ZnO（ZnO/CBD）具有较弱的疏水性，而CTR-VPT法制备的ZnO（ZnO/CTR-VPT）具有较强的亲水性。两种ZnO样品类型都显示出光活性，其中ZnO/CBD显示出比ZnO/CTRVPT更高的所得光电流。对于MB的降解，使用ZnO/CBD作为工作电极可以去除53%的化合物，而使用ZnO/CTR-VPT电极可以去除43%的MB。然而，仅直接光解就可去除39%的甲基溴。使用ZnO/CTR-VPT样品的MB去除率较低与降解过程中的表面解离有关。结果表明，CBD法制备的ZnO纳米棒是一种很有前途的光电极。我们的数据还表明，CTR-VPT生长的纳米棒产生均匀的纳米棒阵列，但这种均匀的纳米结构存款不会导致PEC活性的任何增加。
ZnO nanorods were grown on silicon (Si) substrates by two techniques: (i) Chemical Bath Deposition (CBD) and (ii) a CBD seed layer combined with Carbothermal Reduction Vapor Phase Transport (CTR-VPT). The structured ZnO nanorods were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and contact angle measurments. The photoelectrochemical property of ZnO nanorods were analyzed by linear voltammetry under UV-ABC light excitation. Using the ZnO nanorod samples as photoanodes, the removal of methylene blue (MB) as a representative organic compound was studied by the photoelectrocatalytic (PEC) technique applying a potential (E) of 0.6 V. For comparison purposes, experiments were performed under the same conditions using photocatalysis (PC), direct photolysis and using samples of pure Si (support material) as working electrodes in PEC. XRD analyses of ZnO prepared by both methods showed the expected ZnO wurtzite phase and a preferred c-axial orientation in the growth of the nanorods. The presence of ZnO was further confirmed by XPS and contact angle measurements showed that ZnO grown by CBD (ZnO/CBD) had a slightly hydrophobic behavior while ZnO grown by CTR-VPT (ZnO/CTR-VPT) is hydrophilic. Both ZnO sample types were shown to be photoactive, with ZnO/CBD showing higher resultant photocurrent compared to ZnO/CTRVPT. For the degradation of MB 53% of the compound was removed using ZnO/CBD as a working electrode, while using the ZnO/CTR-VPT electrode led to a removal of 43% of MB. However, direct photolysis alone removed 39% of the MB. The lower removal of MB using ZnO/CTR-VPT samples was related to surface dissociation during the degradation process. The results show that ZnO nanorods prepared by the CBD techique are a promising photoelectrode for PEC applications. Our data also indicate that CTR-VPT-grown nanorods produce uniform nanorod arrays, but this uniform nanostructure deposit does not lead to any increase in PEC activity.