A study of monitoring hydrogen using mesoporous TiO2 synthesized by anodization

We present a hydrogen sensor using mesoporous TiO2 film on silicon and its H2 sensing properties at different conditions. The sensor was formed by anodizing a sputtered Ti layer on silicon and having it annealed for crystallization. The material and electrical characterization included a study of morphology (FESEM), elemental composition (EDS), crystalline structure (XRD) and current–voltage behavior (semiconductor parameter analyzer). The sensor with Pt electrodes showed promising hydrogen sensing properties in air, such as good response to low hydrogen concentration (20–1000 ppm), fast response time of 5 s and recovery time of 125 s at 1000 ppm. The sensor response is shown to be independent toward relative humidity in the testing atmosphere.