†Institute of Physics, Sachivalaya Marg, Bhubaneswar 751005, India.
‡CSIR-Institute of Minerals and Materials Technology, Bhubaneswar 751013, India.
ACS Appl Mater Interfaces. 2015 May 13;7(18):9486-96. doi: 10.1021/acsami.5b00634. Epub 2015 May 1.
A simple single-step chemical vapor deposition (CVD) method has been used to grow the faceted Au-ZnO hetero-nanostructures (HNs) either with nanowires (NWs) or with triangular nanoflakes (TNFs) on crystalline silicon wafers with varying oxygen defect density in ZnO nanostructures. This work reports on the use of these nanostructures on substrates for photodegradation of rhodamine B (RhB) dyes and phenol under the visible light illumination. The photoluminescence measurements showed a substantial enhancement in the ratio of defect emission to band-edge emission for TNF (ratio ≈ 7) compared to NW structures (ratio ≤ 0.4), attributed to the presence of more oxygen defects in TNF sample. The TNF structures showed 1 order of magnitude enhancement in photocurrent density and an order of magnitude less charge-transfer resistance (R(ct)) compared to NWs resulting high-performance photocatalytic activity. The TNFs show enhanced photocatalytic performance compared to NWs. The observed rate constant for RhB degradation with TNF samples is 0.0305 min(-1), which is ≈5.3 times higher compared to NWs case with 0.0058 min(-1). A comparison has been made with bulk ZnO powders and ZnO nanostructures without Au to deduce the effect of plasmonic nanoparticles (Au) and the shape of ZnO in photocatalytic performance. The results reveal the enhanced photocatalytic capability for the triangular nanoflakes of ZnO toward RhB degradation with good reusability that can be attracted for practical applications.
一种简单的单步化学气相沉积（CVD）方法已被用于在具有不同氧缺陷密度的 ZnO 纳米结构的晶体硅衬底上生长具有纳米线（NWs）或三角形纳米薄片（TNFs）的 facet Au-ZnO 异质纳米结构（HNs）。本工作报道了这些纳米结构在光降解罗丹明 B（RhB）染料和苯酚方面的应用在可见光照射下。光致发光测量表明，TNF（比率≈7）的缺陷发射与带边发射的比率相对于 NW 结构（比率≤0.4）有很大的增强，这归因于 TNF 样品中存在更多的氧缺陷。与 NWs 相比，TNF 结构的光电流密度提高了 1 个数量级，电荷转移电阻（Rct）降低了 1 个数量级，从而表现出高性能的光催化活性。TNFs 比 NWs 表现出更高的光催化性能。观察到 TNF 样品降解 RhB 的速率常数为 0.0305 min-1，约为 NWs 情况下 0.0058 min-1 的 5.3 倍。与 ZnO 体粉末和没有 Au 的 ZnO 纳米结构进行了比较，以推断等离子体纳米颗粒（Au）和 ZnO 的形状对光催化性能的影响。结果表明，ZnO 三角形纳米薄片对 RhB 降解具有增强的光催化能力，且具有良好的可重复使用性，可吸引实际应用。
