中国微米纳米 花状Au-SnO2复合材料的制备及其对甲醛气敏性能的研究

利用水热法合成了花状SnO2微米材料,并以它作为基体,对其进行Au纳米颗粒修饰,得到了花状Au-SnO2复合材料.利用X射线衍射(XRD)、扫描电子显微镜(SEM)、X射线光电子能谱(XPS)分析等表征手段对所制备的Au-SnO2复合材料进行了表征分析,结果表明,这种花状结构的材料是由厚度为30 nm～60 nm的SnO2纳米片自组装而成,其尺寸为1 μm～2 μm.同时,我们用花状SnO2和Au修饰的花状SnO2复合材料对1×10-6～500×10-6的甲醛进行了气敏性能测试.结果表明,通过Au修饰,花状SnO2对甲醛的气敏性能有了极大的提高.当甲醛浓度为200×10-6时,其灵敏度(Ra/Rg)约为120,是花状SnO2敏感材料的8倍,表现出很高的响应.另外,由Au修饰的花状SnO2复合材料制成的敏感元件对甲醛表现出良好的选择性.这可能归因于Au纳米颗粒高效的催化活性促进了甲醛气体的扩散和O2的吸附,从而使其表现出更加优异的气敏性能.

Fabrication of Flower-like Au-SnO2 Composite Materials with Enhanced Formaldehyde Gas-Sensing Properties

Flower-like SnO2 micro-nanomaterials were successfully synthesized using hydrothermal method and with it as substrates,then Au nanoparticles to decorated,getting a flower-like Au-SnO2 composite sensitivematerial.The as-synthesized flower-like Au-SnO2 composite materialwere characterized by X-ray power diffraction(XRD),scanning electron microscopy(SEM),and X-ray photoelectron spectra(XPS),and the results showed that the flower-like structure material is self-assembled by SnO2 nanoplates with thickness of 30 nm～60 nm,the size is 1 μm～2 μm.Subsequently,the sensitivity of SnO2 and Au-decorated SnO2 samples toward formaldehyde(1×10-6～500×10-6)was investigated.It was shown that the flower-like SnO2 decorated with Au exhibited very high responses towards 200×10-6 formaldehyde(Ra/Rg=120),which is eight times of the undecorated flower-like SnO2.In addition,Au-decorated flower-like SnO2 sensitive element showed good selectivity towards formaldehyde.This may ascribe to the catalytic activity of the Au nanoparticle which makes it easier for the diffusion of the formaldehyde gas and the adsorption of O2.