Author :
Li, Dian Qing ; Huang, Xiao Wei ; Bai, Shou Li ; Zhou, Guo Jun ; Luo, Rui Xian ; Chen, Ai Fan
Abstract :
A novel CH4 gas sensor based on the nanocomposites and mixed oxides of Sn, In, and Ti, workable at near room temperature, were developed. The binary and ternary oxides were prepared by a chemical controlled step precipitation method and mixed route. The preparation parameters-salt concentration, cation ratio, precipitation pH, and aging time-have been optimized, and their optimal value were 0.05 M, 20% Ti: 20% In: 60% Sn, pH=8.0 and aged 24 h, respectively. The appropriate calcinations temperature for precursor and mixture were 600 degC 4 h and 700 degC 2 h. The performance and structure of the materials were characterized by TEM, BET, TG-DTA, XRD, TPD, and XPS. The sensing tests showed that these nanomaterials exhibited high sensitivity and selectivity for CH4 and their sensing properties depended on the oxide composition, calcinations temperature, operating temperature, and gas concentration. The gas-sensing mechanism of the sensor was also discussed by TPD and XPS analysis
Keywords :
elemental semiconductors; gas sensors; indium; nanocomposites; organic compounds; pH; tin; titanium; 2 hrs; 24 hrs; 4 hrs; 600 C; 700 C; BET; In; Sn; TEM; TG-DTA; TPD; Ti; XPS; XRD; aging time; binary oxides; calcination temperature; cation ratio; chemical controlled step precipitation method; gas concentration; gas sensor; nanocomposites; nanosized oxides; precipitation pH; salt concentration; ternary oxides; Aging; Calcination; Chemicals; Gas detectors; Nanocomposites; Temperature dependence; Temperature sensors; Testing; Tin; X-ray scattering; $hbox {CH}_{4}$ sensor; Sn-In-Ti; mixed oxide; nanocomposite;
