超长氧化锌纳米线的制备及其气敏性能和紫外传感应用研究

采用一种无需催化剂和载气的简便碳热还原法制得长度约为100 μm、直径约为500 nm、长径比达到200的超长ZnO纳米线，讨论了Si基底位置、沉积时间以及反应物原料的量对ZnO纳米线形貌的影响。对ZnO纳米线的气敏性能进行研究，结果表明：在工作温度为350 ℃时，ZnO纳米线传感器能够很好地检测酒精气体，具有选择性好、响应恢复快的优点，且最低检测体积分数为5×10^-6。另外，通过一种简单、实用的介电泳法制得基于ZnO纳米线的紫外传感器。在365 nm紫外灯照射下，光电流增加了13%；而在254 nm紫外灯照射时，光电流则没发生变化，说明该传感器对不同波长的紫外光有一定的选择性。

Preparation of Ultra-long ZnO Nanowires and Its Gas Sensing Properties and UV Sensing Application

A simple and facial carbothermal reduction method was utilized to prepare ultra-long ZnO nanowires with lengths of about 100 μm, diameters of about 500 nm, aspect ratio up to 200 without usage of any catalyst and carrier gas. The effects of the positions of Si substrate, deposition time and the amount of reactant materials on the morphology of ZnO nanowires were studied. The gas sensing results of ZnO nanowires show that ZnO nanowire sensors have a good performance to alcohol with good selectivity, fast response and recovery at the working temperature of 350 ℃, and the detectable volume fraction is as low as 5×10^-6. In addition, a UV sensor based on ZnO nanowires was constructed through a simple and practical dielectrophoresis method. The photocurrent of the sensor increases about 13% under 365 nm UV illumination but has no changes under 254 nm UV irradiation, which indicates the good selectivity of the sensor.