花状SnO_2纳米粉体的制备与气敏性能

Preparation and Gas-sensing Performance of Flower-like SnO_2 Nanopowders

由于纳米颗粒形貌对其气敏性具有重要的影响,本文采用水热法制备了SnO_2纳米粉体,考察了溶液pH值、水热反应温度、时间以及表面活性剂对SnO_2粉体晶相结构及形貌的影响,通过XRD和SEM对其物相结构及微观形貌进行分析。结果表明:当溶液pH值为4,水热反应温度为220℃、时间为12 h时最佳,制备的金红石型SnO_2纳米颗粒呈现花状生长,由平均直径为40 nm,长度约为100nm的纳米棒组成,而添加表面活性剂则可以改变SnO_2纳米棒聚集生长的形貌。花状SnO_2颗粒制备的气敏元件在300℃下对70μL·L-1的乙醇气体的灵敏度为6.5,响应-恢复时间为2s和20s。

Due to the importance of morphology of nanoparticles to gas-sensing performance,flower-like SnO2 nanopowders were prepared by a hydrothermal method,and the effects of pH value,hydrothermal temperature/time,and surfactants on crystal structure and morphology of the SnO2 nanopowders were investigated.The crystal structure and morphology of the samples were characterized by means of X-ray diffraction(XRD)and scanning electron microscopy(SEM).The experimental results indicated in the absence of surfactants,the rutile phase SnO2 nano particles were of flower-like structure,consisting of nano-rods with the diameter of 40 nm and the length of 100 nm,when the pH value was 4,the hydrothermal temperature and time were 220°C and 12 h,respectively.The surfactants changed the conglomeration growth morphology of SnO2 nano-rods.The SnO2 sensor has a better response,up to 6.5,for 70μL·L^-1 ethanol gas at the optimal working temperature,300°C.The fast response time and recovery time are 2 s and 20 s,respectively.