三维有序In2O3纳米线阵列的合成及纳米结构有序度对气敏性能的影响

采用SBA-15硬模板复制技术合成出三维有序纳米线阵列结构的In₂O₃, 通过离心分离获得了2个尺寸不同的块状颗粒样品. 利用XRD、 SEM和紫外-可见光谱对样品的晶体结构、 晶粒尺寸、 形貌及带隙宽度进行了分析. 结果表明, 2个样品具有相同的纳米微结构, 均为由晶粒尺寸约12 nm的近球形In₂O₃晶粒规则有序排列生长而成的三维纳米线阵列结构, 纳米线的直径约为12 nm, 间距约为2 nm, 且块状尺寸较大样品的带隙宽度略大. In₂O₃样品对乙醇气体的气敏性能测试结果显示, 当乙醇气体在空气中的体积分数为100×10^-6, 温度为320 ℃时, A样品的灵敏度达到50. 6, 优于尺寸较小的B样品. 通过对比研究发现该纳米结构样品的气敏性能明显优于同级别纳米颗粒和介孔结构材料, 纳米材料的气敏性能随纳米结构形态有序度的增加而提高.

Synthesis of Three-dimensional Ordered In2O3 Nanowire Arrays and the Effect of Nanostructure Order on Gas Sensitivity

Three-dimensional ordered In₂O₃ nanowire arrays were synthesized using SBA-15 silica as hard template with replication technology， and then the two In₂O₃ samples with different particle sizes were separated with centrifugal separation technology. The crystal structure， grain size， morphology and bandgap of both samples were characterized by means of XRD， SEM and UV-Vis spectroscopy. Both In₂O₃ samples present three-dimensional nanowire array structures， which are orderly assembled with the spherical In₂O₃ particles with grain size of 12 nm. The diameter and interwire distance of In₂O₃ nanowires is about 12 nm and 2 nm， respectively， while the bandgap of In₂O₃ nanowires with the larger particle size is slightly larger than that with the smaller particle size. The sensitivity of In₂O₃ nanowires with the larger particle_{size reaches up to 50. 6 to the ethanol gas with volume ratios of 100×10^-6 in air at 320 ℃， which is higher than that with the smaller particle size. Finally， the gas-sensing performance of In2O3 nanowires with the larger particle is obviously better than those of the similar nanoparticles and mesoporous nanostructures， indicating that the order degree of In2O3 nanowire greatly affects the gas-sensing properties of nanostructures.}