Highly Sensitive Room Temperature H2S Gas Sensor Based on the Nanocomposite of MoS2-ZnCo2O4.

The stacking 2D materials, such as molybdenum disulfide (MoS2), are among the most promising candidates for detecting H2S gas. Herein, we designed a series of novel nanocomposites consisting of MoS2 and ZnCo2O4. These materials were synthesized via a simple hydrothermal method. The microstructure and morphology of nanocomposites were studied by different characteristics such as X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, high-resolution transmission electron microscopy, Brunauer-Emmett-Teller (BET), and X-ray photoelectron spectroscopy. These nanocomposites were used as gas sensors, and the highest response (6.6) toward 10 ppm of H2S was detected by the gas sensor of MZCO-6 (having MoS2 contents 0.060 g) among all other tested sensors. The response value (Ra/Rg) was almost three times that of pure ZnCo2O4 (Ra/Rg = 2). In addition, the sensor of MZCO-6 exposed good selectivity, short response/recovery time (12/28 s), long-term stability (28 days), and a low detection limit (0.5 ppm) toward H2S gas at RT. The excellent performance of MZCO-6 may be attributed to some features of MoS2, such as stack structure, higher BET and surface area and active sites, a synergistic effect, etc. This simple fabrication sensor provides a novel idea for detecting H2S gas at RT.

MoS2-NiO nanocomposite for H2S sensing at room temperature.

The layered 2-D materials, such as molybdenum disulfide (MoS2), are among the most promising candidates for detecting H2S gas at very low concentrations. Herein, we have designed a series of novel nanocomposites consisting of MoS2 and NiO. These materials were synthesized via a simple hydrothermal method. The microstructure and morphology of nanocomposites were studied using different characterization techniques, such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), Brunauer-Emmett-Teller (BET) analysis, and X-ray photoelectron spectroscopy (XPS). These nanocomposites were used as gas sensors, and the highest response (6.3) towards 10 ppm H2S was detected by the MNO-10 gas sensor among all the tested sensors. The response value (Rg/Ra) was almost three times that of pure NiO (Rg/Ra = 2). Besides, the MNO-10 sensor exposed good selectivity, short response/recovery time (50/20 s), long-term stability (28 days), reproducibility (6 cycles), and a low detection limit (2 ppm) towards H2S gas at RT. The excellent performance of MNO-10 may be attributed to some features of MoS2, such as a layered structure, higher BET surface area, higher active sites, and a synergistic effect between MoS2 and NiO. This simple fabrication sensor throws a novel idea for detecting H2S gas.

H2S/Butane Dual Gas Sensing Based on a Hydrothermally Synthesized MXene Ti3C2Tx/NiCo2O4 Nanocomposite.

Real-time sensing of hydrogen sulfide (H2S) at room temperature is important to ensure the safety of humans and the environment. Four kinds of different nanocomposites, such as MXene Ti3C2Tx, Ti3AlC2, WS2, and MoSe2/NiCo2O4, were synthesized using the hydrothermal method in this paper. Initially, the intrinsic properties of the synthesized nanocomposites were studied using different techniques. P-type butane and H2S-sensing behaviors of nanocomposites were performed and analyzed deeply. Four sensor sheets were fabricated using a spin-coating method. The gas sensor was distinctly part of the chemiresistor class. The MXene Ti3C2Tx/NiCo2O4-based gas sensor detected the highest response (16) toward 10 ppm H2S at room temperature. In comparison, the sensor detected the highest response (9.8) toward 4000 ppm butane at 90 °C compared with the other three fabricated sensors (Ti3AlC2, WS2, and MoSe2/NiCo2O4). The MXene Ti3C2Tx/NiCo2O4 sensor showed excellent responses, minimum limits of detection (0.1 ppm H2S and 5 ppm butane), long-term stability, and good reproducibility compared with the other fabricated sensors. The highest sensing properties toward H2S and butane were accredited to p-p heterojunctions, higher BET surface areas, increased oxygen species, etc. These simply synthesized nanocomposites and fabricated sensors present a novel method for tracing H2S and butane at the lowest concentration to prevent different gas-exposure-related diseases.

Antimicrobial activity of comfort related properties of silk treated with herbal extracts in making of reusable masks

The study was aimed at divulging an eco-friendly antimicrobial finish on 100 % silk woven fabric. The leaves' extract of Azadirachata indica, Butea monosperma and Litche chinensis were used as the development of eco-friendly antimicrobial finish. The antimicrobial property and comfort related property were checked before and after applying antimicrobial finish. In comfort related property absorbency & air permeability were checked. The ASTEM E2149 Shake Flask method was used to check antimicrobial finish and AATCC method was used for checking fabric property. One way ANOVA statistical test was applied for analysis of results. The FTIR and SEM results showed the presences of finish on fabrics. In comfort related property, absorbency and air permeability was increased. The results showed that antimicrobial finish made 100% reduction against microorganism up to 25 washes which can be used in making reusable masks fight against COVID- 19.