Rakesh K. Sonker

Experimental investigations on NO2 sensing of pure ZnO and PANI–ZnO composite thin films

In the present work, comparative investigations on NO2 gas sensing properties of the hybrid nanocomposite thin films of polyaniline (PANI), ZnO and PANI–ZnO towards NO2 gas at room temperature have been reported. The effect of concentration of PANI in the composite thin films on NO2 gas sensing has been investigated. Structural and surface morphological characterizations have been carried out using X-ray diffraction (XRD) and scanning electron microscopy (SEM) respectively. The presence of 5 wt% PANI in the composite films was found to give a maximum sensing response of ∼6.11 × 102 towards 20 ppm NO2 gas having fast response and recovery time of about 2.16 min and 3.5 min respectively.

Synthesis and porous h-BN 3D architectures for effective humidity and gas sensors

3D (three dimensional) architectures synthesised using an easily scalable solid state method which results in an interconnected network of porous h-BN sheets with boron trioxide are reported in this study. The boron trioxide acts as a nucleating agent for the formation of laterally large nanosheets of h-BN with a low density and increases the specific surface area. The stable form shows improved mechanical properties (experimentally and using MD simulation) and serves as a suitable material for humidity and liquefied petroleum gas (LPG) sensor applications. The sensor shows stability for up to several months without losing its sensitivity.

Sol-gel formed spherical nanostructured titania based liquefied petroleum gas sensor

The present work reports the preparation of Titania(TiO2) thin film by sol-gel technique and its Liquefied Petroleum Gas (LPG) sensing. TiO2 exists in numerous phases possessing different structural properties like amorphous, anatase or anatase/rutile mixed phases. The structural analysis confirmed the formation of TiO2 having an average crystallite size 21 nm. SEM showed the regular and porous surface morphology. The band gap of the material was found as 3.65 eV. This film was employed for LPG sensing and variations in resistance with exposure of LPG were observed. Sensor response (S) as a function of time was calculated and its maximum value was found as 2.8 for 4% vol. of LPG with a response and recovery times of 240 sec and 248 sec respectively.