Enhancing humidity sensing performance through structural and catalytic optimization in platinum-modified ordered mesoporous titania

Platinum modified ordered mesopore TiO2 (OMT:X Pt) with tunable channel was synthesized via soft-templet method known as Evaporation Induced Self-Assembly (EISA). Both porosity and metal doping have a significant impact on how metal oxide semiconductors respond to humidity. Thus, based on earlier studies, Pt-doped ordered mesoporous TiO2 was synthesized and described under optimal conditions. From nitrogen adsorption and desorption analysis, while it was found that the specific surface area decreased (from 240 to 125 m2/g), pore size increased (from 4 to13 nm). The humidity sensing performance of the Pt-modified OMT is investigated by dynamic sensing system. The sensor based on 5 wt% Pt-doped OMT showed high response (SR ∼ 105), fast response time (26 s) to 95 % relative humidity (RH) and good long-term stability (over 90 days). To understand and authenticate the sensing mechanism, the structure and morphology of synthesized Pt-doped OMT was performed by BET, SEM, HRTEM, XRD and XPS. Furthermore, a plausible sensing mechanism is discussed on basis of the obtained results.