原位生长的α-Fe_(2)O_(3)/ZnO异质纳米棒阵列对乙醇气体的高选择性检测

In Situ Deposited Heterogeneousα-Fe_(2)O_(3)/Zn O Nanorod Arrays for Highly Selective Detection of Ethanol

采用两步溶液法在陶瓷管上原位生长了ZnO纳米棒阵列,然后以ZnO纳米棒为载体,通过水热法在其表面负载α-Fe_(2)O_(3)纳米粒子,生成异质α-Fe_(2)O_(3)/ZnO复合纳米材料。α-Fe_(2)O_(3)/ZnO纳米棒直径30~80 nm,长1μm左右,交叉排列形成纳米棒阵列,α-Fe_(2)O_(3)纳米粒子粒径约10 nm,均匀分布在ZnO纳米棒表面。将纯ZnO和α-Fe_(2)O_(3)/ZnO纳米棒阵列制成气敏元件,测试并对比了2种气敏元件的气敏性能,揭示其气敏机理。结果表明:α-Fe_(2)O_(3)纳米粒子的复合显著提高了ZnO纳米棒阵列对乙醇气体的灵敏度和选择性,在工作温度370℃时,对100μL/L乙醇气体的响应值为85.4,是同条件下ZnO器件对乙醇响应值(9.4)的9.1倍,响应时间7 s,最低检出限为0.01μL/L。相关研究可以应用于痕量乙醇的快速、高灵敏度和高选择性检测。

ZnO nanorod arrays were grown in situ on ceramic tubes by a two-step solution method.Thenα-Fe_(2)O_(3)nanoparticles were loaded on the surface of ZnO nanorods via a hydrothermal method to obtain heterogeneousα-Fe_(2)O_(3)/ZnO composites.Theα-Fe_(2)O_(3)/ZnO nanorods are about 30~80 nm in diameter and 1μm in length,which are cross-arranged to form nanorod arrays.α-Fe_(2)O_(3)nanoparticles with a diameter of about 10 nm distributed on the surface of ZnO nanorods evenly.The gas-sensing properties of the sensors based on pristine ZnO andα-Fe_(2)O_(3)/ZnO nanorod arrays were compared,and the gas-sensing mechanism was revealed.The results show that the decoration ofα-Fe_(2)O_(3)nanoparticles significantly enhances the sensitivity and selectivity of ZnO nanorod arrays sensors to ethanol at the working temperature of 370℃.The response ofα-Fe_(2)O_(3)/ZnO sensor to 100μL/L of ethanol is 85.4,which is 9.1 times higher than that of pure ZnO sensor(9.4)determined under the same conditions.The response time is 7 s,and the detection limit is 0.01μL/L.The work can be applied to the rapid,high sensitivity and selectivity detection for trace ethanol.