Liang Yuan-Chang, Xu Nian-Cih
Institute of Materials Engineering, National Taiwan Ocean University Keelung 20224 Taiwan
RSC Adv. 2018 Jun 19;8(40):22437-22446. doi: 10.1039/c8ra04157a.
TiO-ZnS core-shell composite nanorods were synthesized by using ZnO as a sacrificial shell layer in a hydrothermal reaction. ZnO thin films of different thicknesses were sputter-deposited onto the surfaces of TiO nanorods as templates for hydrothermally synthesizing TiO-ZnS core-shell nanorods. Structural analysis revealed that crystalline TiO-ZnS composite nanorods were formed without any residual ZnO phase after hydrothermal sulfidation in the composite nanorods. The thickness of the ZnO sacrificial shell layer affected the surface morphology and sulfur-related surface defect density in hydrothermally grown ZnS crystallites of TiO-ZnS composite nanorods. Due to the distinctive core-shell heterostructure and the heterojunction between the TiO core and the ZnS shell, TiO-ZnS core-shell nanorods exhibited ethanol gas-sensing performance superior to that of pristine TiO nanorods. An optimal ZnO sacrificial shell layer thickness of approximately 60 nm was found to enable the synthesis of TiO-ZnS composite nanorods with satisfactory gas-sensing performance through sulfidation. The results demonstrated that hydrothermally derived TiO-ZnS core-shell composite nanorods with a sputter-deposited ZnO sacrificial shell layer are promising for applications in gas sensors.
通过在水热反应中使用ZnO作为牺牲壳层合成了TiO-ZnS核壳复合纳米棒。将不同厚度的ZnO薄膜溅射沉积到TiO纳米棒表面，作为水热合成TiO-ZnS核壳纳米棒的模板。结构分析表明，复合纳米棒经水热硫化后形成了结晶性的TiO-ZnS复合纳米棒，且无任何残留的ZnO相。ZnO牺牲壳层的厚度影响了TiO-ZnS复合纳米棒水热生长的ZnS微晶的表面形貌和与硫相关的表面缺陷密度。由于独特的核壳异质结构以及TiO核与ZnS壳之间的异质结，TiO-ZnS核壳纳米棒表现出优于原始TiO纳米棒的乙醇气敏性能。发现约60nm的最佳ZnO牺牲壳层厚度能够通过硫化合成出具有令人满意气敏性能的TiO-ZnS复合纳米棒。结果表明，具有溅射沉积ZnO牺牲壳层的水热衍生TiO-ZnS核壳复合纳米棒在气体传感器应用中具有潜力。
