Computational assisted tuning of Co-doped TiO2 nanoparticles for ammonia detection at room temperatures

作者：Chen, Yifan; Wu, Ji; Xu, Zhiwu; Shen, Wenhao^*; Wu, Ying^*; Corriou, Jean-Pierre

来源：Applied Surface Science, 2022, 601: 154214.

DOI：10.1016/j.apsusc.2022.154214

• Gas-sensing
• Ammonia
• Co-doped TiO2
• Room temperature
• DFT

Improved gas sensors based on pure anatase TiO2 and Co-doped TiO2 nanoparticles were evaluated. A cobalt -doped TiO2 nanoparticle with a diameter of 40 nm was first synthesized. The morphology of the nano -particles was analyzed by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy. The doped Co ion was confirmed to have entered the TiO2 lattice. Subsequently, gas sensors with different Co-doping concentrations were developed to investigate gas sensitivity to NH3. Compared with pure anatase TiO2 operating at 180 ?C, Co-doped TiO2 samples were developed as NH3 gas sensors operating at room temperature. The 20% Co-doped sample exhibited the best performance, with a response value of 14 for 50 ppm NH3, which was 7 times higher than that of pure TiO2. The response and re-covery times of the sensor were only 25 and 48 s, respectively, and exhibited both good stability and selectivity. Based on density functional theory (DFT), the calculated bandgap of Co-doped TiO2 decreased by 72% compared to pure TiO2. Structural simulation and mechanism analysis elucidated the good gas-sensing performance at room temperature and the property enhancement of the Co-doped TiO2 gas sensor.

• 单位
  y; 1; 广东工业大学