CdS nanodroplets over silica microballs for efficient room-temperature LPG detection

An efficient room-temperature sensor for liquified petroleum gas (LPG) is demonstrated by employing CdS:SiO₂ nanocomposite thin films (CdS:SiO₂ NCTFs) for the first time. CdS:SiO₂ NCTFs exhibiting the morphology of CdS nanodroplets on micron-sized spherical balls of SiO₂ were deposited using the pulsed laser deposition (PLD) method, followed by thermal annealing. The targets of chemically synthesized CdS nanoparticles and commercially procured SiO₂ were used to deposit CdS:SiO₂ NCTFs by swapping them at a frequency ratio of 2 : 8 laser pulses per second, which was selected to ensure nearly the same ratio of CdS to SiO₂ in NCTFs and was confirmed by X-ray photoelectron spectroscopy. Sensor fabrication was carried out on bare CdS thin films and as-grown and annealed CdS:SiO₂ NCTFs using an Ag paste over Pt interdigitated electrodes to measure the resistance of the films in air and in the presence of reducing gases, viz., LPG, H₂, H₂S, NO₂ and CO₂. The present sensor showed the highest response for LPG and the observed value was ∼71% for 1000 ppm at RT with the response time and recovery time of 91 s and 140 s, respectively. The response of the sensor was sustainable up to 75 °C and then decreased, which suggested its promising usage for low-temperature regions as well. A low detection limit of 20 ppm at RT for LPG was determined; however, a significant response was observed only at 50 ppm. The sensor retained ∼96% of its initial response even after 8 weeks and that too at 100 °C. The present LPG sensor is highly promising due to its high sensitivity, low detection limit, low response and recovery times, good reproducibility, RT operation and simple fabrication technique.

The synthesis of multifunctional porous honey comb-like La2O3 thin film for supercapacitor and gas sensor applications

The porous honey comb-like La₂O₃ thin films have been synthesized using one step spray pyrolysis method. The influence of sprayed solution quantity on properties of La₂O₃ thin films is studied using X-ray diffraction, Fourier transform spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, optical absorption and Brunauer-Emmett-Teller techniques. Morphology of La₂O₃ electrode is controlled with sprayed solution quantity. The supercapacitive properties of La₂O₃ thin film electrode are investigated using cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance techniques. The La₂O₃ film electrode exhibited the specific capacitance of the 166Fg^-1 with 85% stability for the 3000 cycles. The La₂O₃ film electrode exhibited sensitivity of 68 at 523K for 500ppm CO₂ gas concentration. The possible CO₂ sensing mechanism is discussed.

Electrical and electrochemical properties of graphene modulated through surface functionalization

The present work emphasizes a variety of electrical and electrochemical properties of graphite nano-materials (GNMs) with respect to their extent of functionalization.

Synthesis and sensing applications of polyaniline nanocomposites: a review

A comprehensive review on the synthesis of PANI nanocomposites and their applications as gas sensors and biosensors has been presented.

Performance of hybrid nanostructured conductive cotton materials as wearable devices: an overview of materials, fabrication, properties and applications

Recent advances and overview of hybrid nanostructured cotton materials will boost an essential encouragement for the development of next generation smart textiles and flexible devices which could be worn by human beings.