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The development of room temperature gas sensors is vital for power-efficient applications. In this work, we investigated the room temperature sensing of hydrogen sulfide (H2S) gas with zin tin oxide (ZTO) bottom gated thin film transistor. Exposure to 50 ppm H2S for 60 seconds shows a negative shift in the transfer curve. Being a TIT-based sensor, a number of parameters can be taken into account to sense the analyte gas. At room temperature, the device shows no response to other analyte gases used in the study. With exposure to H2S, a negative threshold voltage shift of 0.9 V was observed. The device showed a response of 3.2 at room temperature when operated in the subthreshold swing region. [ABSTRACT FROM AUTHOR]

The current study focusses on the preparation, characterization and tribo property evaluation of polydimethylsiloxane (PDMS)/ poly(o-anisidine) (POA) composites. POA was synthesized by chemical oxidative polymerization of o-anisidine using ammonium persulfate as initiator and 1 M CSA as dopants at room temperature. The poly (o-anisidine) prepared was characterized using UV, FTIR, TEM and TGA analysis. PDMS/POA composite was prepared by ultrasonication assisted mixing followed by the room temperature curing using TEOS as curing agent and DBTDL as the accelerator in the ratio 100:10:1. A vertical contact mode TENG was fabricated by sandwiching the composite between two copper electrodes. Different compositions of PDMS/POA composite was prepared by varying the POA wt% in PDMS from 1wt% to 6wt% with respect to PDMS. The triboelectric properties such as short circuit current and open circuit voltage were increased upto 4wt% POA addition and then further addition the tribo properties were decreased. A maximum short circuit current of 13 µA and an open circuit voltage of 67.56 V was observed for PDMS/POA(4wt%) composite, which is higher than the open circuit voltage (27.3 V) and short circuit current (4.6 µA) of bare PDMS [ABSTRACT FROM AUTHOR]

Flexible smart energy devices are quickly advancing its applications in wide areas such as home appliances, health care, construction, education etc. Triboelectric nanogenerators are fast developing technology accomplishing this smart energy devices by coupling two physical phenomena; contact electrification and electrostatic induction. Here, a PDMS based triboelectric nanogenerator was fabricated by using exfoliated hexagonal Boron Nitride Nanosheets (BNNS) as filler material. Polydimethylsiloxane (PDMS)-exfoliated BNNS composites are synthesized via room temperature curing method. This is promising flexible composite material have immense application in smart energy devices. Here, BNNS powder of varying weight percentages, namely 2%, 4%, 6%, and 8% were incorporated in PDMS to form composite that are showing high enhancement in triboelectric output (short circuit current and open circuit voltage) via combined effect piezoelectric effect and triboelectric effect. A vertical contact-separation mode with metal to dielectric structure having composite material as dielectric material exhibited a maximum peak short circuit current of 15 µA which is three times enhancement compared to pure PDMS and peak open circuit voltage of 150 V which is two times enhancement under the excitation of 10 N force at 10 Hz frequency. As a flexible triboelectric material, it promises wide applications in harvesting unutilized mechanical energy from various sources such as biomechanical energy, automotive part movement, wave energy etc. [ABSTRACT FROM AUTHOR]

Triboelectric nanogenerators (TENGs) caught attention globally due to its ability to convert mechanical energy from our surroundings into electrical energy. Demand for the power sources arose due to the swift progress in the use of portable and personal electronic gadgets which includes touch screens, electronic skins, health care and environmental monitoring, national security and so on. Improvement of output performance of TENG is a main challenge for utilizing them for different applications. Dielectric tuning is one of the strategies used for enhancing the output performance. Conductive nanoparticles were introduced into poly-dimethyl siloxane (PDMS) polymer matrix which significantly improved the dielectric constant of the polymer-metal composites. The effect of dielectric constant on the output performance is conferred experimentally which shows a direct influence of surface charge density and charge transfer on the relative permittivity of the tribo-material used. A comparative study on the output performance of TENG has been done by introducing silver and aluminium metal nanoparticles into the PDMS matrix. Results indicates that the permittivity of the tribo-material got improved and revealed better performance against TENG based on pure PDMS film. The weight percentage of metal nanoparticles were varied systematically and corresponding variations in the dielectric constant of the polymer composite films were examined. The open circuit voltage (Voc) and short circuit current (lsc) increased as the weight percentage of metal nanoparticles increased and better values were obtained for 20 wt% silver-PDMS composite. TENG based on metal nanoparticle-PDMS composite films were prepared by optimizing the electrical properties of the tribo-material with the aim to improve the output performance oftriboelectric nanogenerators. [ABSTRACT FROM AUTHOR]

The world has acknowledged the significance of sustainable energy harvesting following the mishap of global warming hanged with the bitterness of the energy crisis. The fascinating idea of pooling energy from the ambient environment via highly economical and versatile means drives the latest technique named triboelectric nanogenerator the most desirable among many. The ubiquitous irregular mechanical energy in the low-frequency form can be converted into electrical energy efficiently by choosing the right triboactive materials carrying strong fundamental counter affinities that can draw high potential differences after getting separated once they come in contact with each other. Herein, we explore the prospects of Nylon-6,6 as an affordable and promising tribopositive material that upholds notable thermal stability and mechanical strength that is paired well with the distinguished flexible tribonegative polydimethylsiloxane (PDMS) film. The study reveals an increment in the triboelectric output performance while adding aqueous glycerol as a plasticizer from 3.1µA short circuit current to 5.1µA within just 4cm2 area of the dielectric films via contact separation mode. The additive enhances the charge development through the electron-donating hydroxyl groups, besides alleviating the brittleness of the whole film. The findings open up numerous creative possibilities for the less explored Nylon-6,6 as a triboelectric material with its unique abrasion resistance and excellent waterproof nature, which is simply a solution cast at room temperature. This marks its efficacy as an outstanding industrially affable material for developing multi-purpose-light-weight devices with energy harvesting functionality. [ABSTRACT FROM AUTHOR]

Radio frequency magnetron sputtering is an efficient deposition method to produce good quality thin films. Usage of such an industry viable method in the deposition of materials like tungsten disulfide (WS2) can be a major leap in the semiconductor industry owing to the fascinating properties that WS2 possess. Here we report the deposition of two dimensional WS2 on quartz substrates using a one-step sputtering process in which metal tungsten is sputtered in sulfur ambience. The absorbance spectra of the samples showed the excitonic peaks of WS2. From the Raman spectra, we were able to confirm the formation and purity of WS2 in the sputtered samples. [ABSTRACT FROM AUTHOR]

The unique properties of two-dimensional (2D) transition metal dichalcogenides (TMDCs) have been attracting a wide variety of researches in material engineering. Enormous attention has been paid in this area due to their unique properties and potential applications in optoelectronics. In the group of these TMDCs, MoS2 is one of the most important one due to its tuneable properties. Nanostructured MoS2 are promising and desirable candidates as catalysts in hydrogen evolution reaction (HER). Platinum, the traditionally used catalyst for HER can be replaced by the earth abundant and cost effective MoS2 nanostructures. A simple route is adopted here for the synthesis of MoS2 quantum dots (MoS2 QDs) by using a single precursor in aqueous medium. The characterization studies of the prepared MoS2 QDs show the uniform size of the MoS2 QDs with an average size 3 nm. They exhibit excellent photoluminescence emission spectra with 553.3 nm peak. Polarisation graph with an overpotential of 463 mV at 10 mA Current, Tafel plot with a slope of 58 Mv / Dec and Nyquist plot with a charge transfer resistance of 878 ohms suggests it as an efficient catalyst for HER. [ABSTRACT FROM AUTHOR]