Zhong Li,Azhar Ali Haidry,BaoXia Dong,LinChao Sun,Qawareer Fatima,LiJuan Xie,ZhengJun Yao
Long range nitrogen doped ordered mesoporous TiO 2 (N-OMT) structures having pore size 3–4 nm and wall thickness ∼2 nm were synthesized via multi-component process and then characterized by XRD , Raman spectra, BET, SEM, TEM , and XPS . Afterwards, powders of N-OMT were sprayed on the ceramic substrates with Au interdigitated electrodes to apply as humidity sensors and conduct systematic dynamic humidity sensing tests under dark conditions and room temperature via a custom-made gas-sensing test system. High resistance variation (>10 5 ) towards 90% RH reveals its high sensitivity and application potential. The results indicate that nitrogen doping and mesoporous structure are synergistically conducive to enhancing the humidity sensing properties and evaporation induced self-assembly (EISA) strategy should be one of the most effective and significant approaches to prepare the higher performance humidity sensing materials. Based on the characterization and analysis, as well as the comparison with other sensors based on OMT and Commercial powders, a reasonable humidity sensing mechanism aim to explain the enhancement of N-OMT sensor's performances is discussed in detail.
Azhar Ali Haidry,Qawareer Fatima,Zhe Wang,Yucheng Wang,Yinwen Ji,Adil Raza
Owing to their unique surface adsorption characteristics, the controlled synthesis of highly ordered mesoporous materials with high adsorption traits is of utmost importance. In the present work, ordered mesoporous TiO 2 (OMT) with tunable channels was prepared via a facile soft-templet evaporation-induced self-assembly (EISA) method. The effect of phenol-formaldehyde resins (PF) and the ratio of triblock copolymer (F127) and tetrabutyl titanate (TBOT) on the OMT surface was studied by Brunauer Emmett Teller (BET) and scanning electron microscopy (SEM) analysis. The samples without PF resol did not offer any ordered mesoporous formation, while a highly ordered mesoporous structure was obtained for samples with PF resol. For the prepared samples, the specific surface area SSA∼141–254 m 2 /g, average pore size S P ∼5.3–9.8 nm and pore volume V P ∼0.29–0.45 cm 3 /g were obtained by controlling the ratio of F127 and TBOT. For 95% relative humidity (RH), the OMT with optimum specific surface area (SSA∼220 m 2 /g) and small pore size (S P ∼5.3 nm) showed a high response (S R ∼3.5 ×10 5 ), fast response time (26 s) and good long-term stability (over 90 days). Finally, the structure, morphology and chemical composition of the samples were determined by XRD , SEM, HRTEM , and XPS techniques to predict and authenticate the plausible sensing mechanism.
危险品化学品经营许可证（带存储）