PrGO decorated TiO2 nanoplates hybrid nanocomposite for augmented NO2 gas detection with faster gas kinetics under UV light irradiation

Controlling the anatase TiO2 based-rectangular nanoplates (NPs) with {001} faces have gained immense interest in gas sensors applications, since the rectangular NPs of {001} planes are highly reactive for the adsorption of oxygen species that led to significant improvement in gas sensing performance. In this work, we report on the room temperature (RT) NO2 gas sensing performances of hybrid nanocomposites with the interpenetrated network using p-Phenylenediamine-reduced graphene oxide (PrGO) decorated TiO2 NPs. The fabricated TiO2 NPs/PrGO heterostructure sensor demonstrated the superior NO2 response (∼14.9% to 100 ppm of NO2) compared to TiO2/rGO and pristine TiO2 nanoplates. On the other hand, the TiO2 NPs/PrGO heterostructure device showed high sensitivity, repeatability and excellent selectivity with short response/recovery times towards NO2 gas at RT. Further, the performances of the TiO2NPs/PrGO gas sensor was accelerated by UV irradiation (λ = 365 nm), and the response was found as ~35.68% to 100 ppm of NO2 at RT, which was ~2.35-fold times higher than the dark condition. The high gas sensing performance would be attributed to the electrical sensitization of PrGO and the ample interface between TiO2 NPs and PrGO that stimulated the charge separation with faster charge transport characteristics. Our strategy and results shed new light to exploit diverse functionalized materials to the high response gas sensors at RT.