Zhou Xiaoyan, Tao Tiyue, Bao Yuwen, Xia Xiaohong, Homewood Kevin, Wang Zhuo, Lourenço Manon, Huang Zhongbing, Shao Guosheng, Gao Yun
Ministry-of-Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, School of Materials Science & Engineering, Hubei University, Wuhan 430062, China.
State Center for International Cooperation on Designer Low-Carbon & Environmental Materials, Zhengzhou University, 100 Kexue Avenue, Zhengzhou 450001, China.
ACS Appl Mater Interfaces. 2021 Jun 2;13(21):25472-25482. doi: 10.1021/acsami.1c02050. Epub 2021 May 23.
Pt decoration is known to be one of the most promising strategies to enhance the performance of TiO hydrogen gas sensors, while the effect of Pt-decorating concentration on the sensing performance of TiO and the specific interaction between Pt and TiO have not been fully investigated. Here, a series of TiO nanoarray thin films with differing amounts of Pt decorated (Pt/TiO) is fabricated, and the H-sensing performance is evaluated. A switch in the response from P-type to N-type is observed with increasing Pt decoration. The response additionally depends on the H concentration: resistance increases in low H concentrations and decreases in hydrogen concentrations higher than 40 ppm. This is explained by the competitive adsorption of hydrogen between the Pt nanoparticles (Pt NPs) and the exposed TiO surface. The preference for H adsorption and splitting between Pt and TiO is established by DFT calculations. Humidity brings preferential adsorption of HO on the surface of Pt, which affects the following adsorption and splitting of H, thus resulting in a P-N switch of the sensing performance. The detailed dynamic reaction process is described according to the findings.
众所周知，铂修饰是提高二氧化钛氢气传感器性能最具前景的策略之一，然而，铂修饰浓度对二氧化钛传感性能的影响以及铂与二氧化钛之间的特定相互作用尚未得到充分研究。在此，制备了一系列具有不同铂修饰量的二氧化钛纳米阵列薄膜（Pt/TiO），并对其氢气传感性能进行了评估。随着铂修饰量的增加，观察到响应从P型转变为N型。响应还取决于氢气浓度：在低氢气浓度下电阻增加，而在氢气浓度高于40 ppm时电阻降低。这是由铂纳米颗粒（Pt NPs）与暴露的二氧化钛表面之间氢气的竞争吸附所解释的。通过密度泛函理论（DFT）计算确定了铂和二氧化钛之间对氢吸附和分解的偏好。湿度使羟基（HO）优先吸附在铂表面，这影响了随后氢的吸附和分解，从而导致传感性能的P-N转变。根据研究结果描述了详细的动态反应过程。
