Key Laboratory of Macromolecular Science of Shaanxi Province, School of Materials Science and Engineering, Shaanxi Normal University, Xi'an, 710062, China.
ACS Appl Mater Interfaces. 2013 Apr 24;5(8):3033-41. doi: 10.1021/am303012u. Epub 2013 Apr 5.
Vertically aligned SnO2 nanocones with different morphologies have been directly grown on fluorine-doped tin oxide (FTO) glass substrates in a large area by heating a mixture of stannous chloride dihydrate (SnCl2·2H2O) and anhydrous zinc chloride (ZnCl2) at 600 °C in air. Control over the SnO2 nanocone arrays with different morphologies is achieved by adjusting the heat treatment time. The SnO2 nanocones are single crystalline with the tetragonal structure. A single-layer SnO2 nanoparticle film is first formed via the vapor-solid (VS) process due to the decentralization function of ZnCl2 vapor, and the SnO2 nanoparticles served as seeds and grew into nanocone arrays via the VS process. The sharp-tipped nanostructure formation may originate from a concentration gradient of reactant in the growth process. The as-obtained whiskerlike nanocone arrays exhibit enhanced field emission properties in comparison with typical nanoconelike structure arrays and other SnO2 nanostructured materials reported previously, and the turn-on field and field-enhancement factor is 1.19 V/μm and 3110, respectively. The experimental result is consistent with the Utsumi's relative figure of merit for pillar-shaped emitters.
在空气中，通过加热二水合氯化亚锡（SnCl2·2H2O）和无水氯化锌（ZnCl2）的混合物，在 600°C 的温度下，可以在大面积的氟掺杂氧化锡（FTO）玻璃衬底上直接生长具有不同形貌的垂直排列的 SnO2 纳米锥。通过调整热处理时间，可以控制 SnO2 纳米锥阵列具有不同的形貌。SnO2 纳米锥为具有四方结构的单晶。由于 ZnCl2 蒸气的分散作用，首先通过汽-固（VS）过程形成单层 SnO2 纳米颗粒膜，然后 SnO2 纳米颗粒作为种子通过 VS 过程生长成纳米锥阵列。锐化的纳米结构的形成可能源于生长过程中反应物的浓度梯度。与之前报道的典型纳米锥状结构阵列和其他 SnO2 纳米结构材料相比，所获得的须状纳米锥阵列表现出增强的场发射性能，开启场和场增强因子分别为 1.19 V/μm 和 3110。实验结果与 Utsumi 相对值对于柱形发射器是一致的。
