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

Platinum modified ordered mesopore TiO 2 (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 TiO 2 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 m 2 /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 ∼ 10 5 ), 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.