Room temperature rapid detection of toxic gases is still ambitious for real-time application. Recently, molybdenum disulfide transition dichalcogenides (MoS2 TMDCs) have been considered as a ...promising material for gas sensing application, owing to their high surface-to-volume ratio. However low response and incomplete recovery hinder their performance. In this work, we demonstrate MoS2 and cobalt incorporated MoS2 to enhance the sensing response and rapid recovery. Co-incorporated (7 at%) MoS2 showed 546.6% enhancement in response compared to pristine MoS2 for 100 ppm of NO2 gas at room temperature. The enhanced edge site presents in the Co-incorporated samples was the reason for excellent gas adsorption and increased response towards NO2 gas molecules. The stability analysis showed 70% of stability of a fabricated device. These results address a new pathway for an ideal gas sensor for room temperature application.
•The pristine MoS2 and co-incorporated MoS2 was successfully synthesized by hydrothermal method.•Studying the effect of cobalt incorporation in MoS2 and their gas sensing properties via home-made gas sensing unit.•The 7 at% of Co-incorporated MoS2 sample showed enhanced response of 51.08% in 10 s for 100 ppm of NO2 gas.•The uniqueness of our work is to fabricate room temperature gas sensor with enhanced sensitivity of 546.6%.
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•Developed a high-sensitive CuO/rGO heterostructures sensor for NO2 gas detection at RT (30 °C).•The CuO/rGO heterostructures (CR10) sensor showed an incredibly high sensitivity of ...1004 % against 5 ppm NO2 gas.•The CuO/rGO heterostructures (CR10) sensor exhibited extremely rapid response rate of 10 s at RT.•The developed NO2 sensor displays high selectivity, long-term stability (30 days), good linearity, and impressive repeatability.
The process of combusting non-renewable energy sources results in the emission of a variety of harmful gases into the environment. As a result, there is a continuing need for a high-sensitivity gas sensor capable of promptly identifying these gases at room temperature (RT). Herein, we developed a high-sensitive CuO/rGO heterostructures sensor for NO2 gas detection at RT (30 °C) with enhanced sensitivity and short response rate. Interestingly, the developed CuO/rGO (CR10) sample illustrated an incredibly high sensitivity of 1004% against 5 ppm NO2 gas with an extremely rapid response rate of 9 s at RT. The developed CR10 sensor exhibits a 5.17 times ameliorated sensing response against 5 ppm of NO2 gas in contrast to the pristine CuO (CR0) sensor. The developed NO2 sensor also exhibits high selectivity, long-term stability (30 days), good linearity, and impressive repeatability. The synergistic interaction between CuO and reduced graphene oxide (rGO) are primary reason for the enrichment of the sensing performance. In particular, a thin layer of rGO arranged over CuO porous nanosheets and the enormous surface area of CuO/rGO could serve as additional available adsorption centres for NO2 gas and increase the speed of redox reaction on the CuO/rGO sensor surface, resulting in an extremely high sensing response. Furthermore, the rGO thin layer exhibits exceptional carrier transfer capabilities that can be utilized as ultra-responsive conductive channels, thereby enhancing the sensing response significantly. Besides, a significant amount of chemisorbed oxygen species are also relatively favourable for the sensing performance. This study opens up a novel avenue to develop a high-performance NO2 sensors at RT.
Layered transition metal dichalcogenide (TMD) materials possess novel and unique semiconducting properties when exfoliated into thin sheets or individual layers. The exfoliation leads to effective ...sensing towards gas molecule due to the increase in surface-active sites and edge zone disorders. In this work, we present exfoliation of bulk WS
2
sheets with liquid-based dispersion technique using facile bath sonication method for NO
2
molecule sensing. The exfoliated WS
2
nanosheets show reversible and selective response towards NO
2
gas molecules operating at room temperature. The sensitive film shows p-type characteristics providing sensor response rate around 27% for 10 ppm NO
2
with rapid response and recovery time around 45 s and 60 s, respectively. The sensitive response was further studied at high temperature of 150 °C showing a drastic increase in response rate as 45% with effective response and recovery time. This improvement in NO
2
gas sensing was attributed to the facile exfoliation of WS
2
nanosheets.
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•The pristine MoS2 and Ni-MoS2 nanoflowers were synthesized by hydrothermal method.•The optimized Ni-MoS2 exhibited instantaneous response of 45.25% in 28 s.•The plausible mechanism ...explained the enhancement in sensing response.•The novelty of this work is fabricating room temperature gas sensor.
In this work, we report the effect of nickel incorporation into MoS2 nanosheets for room temperature sensing of NO2 gas. Interestingly, the concentration of Ni (3, 5, 7 at.%) ions plays a vital role in enhancing the morphological and optical properties. The increased edge active sites in nickel incorporated samples play a vital role in high-performance gas sensing. 7 at.% of Ni incorporated MoS2 showed 115% enhancement for 200 ppm of NO2 gas molecules at room temperature, compared to pristine and other concentrations of Ni-incorporated sensors. The enhancement in the gas sensing performance was explained by the possible mechanism. In addition to this, the first principle calculations were performed to identify the influence of Ni-atom into the MoS2 matrix. The electronic structure of the material was tuned by the incorporation of Ni-atom into the MoS2. This was confirmed from electronic band structure, PDOS, electron density difference and Bader charge transfer analyses.
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•The shape-controlled SnS2 was synthesized using template-free hydrothermal and solvothermal methods.•The enormous active sites increase the sensing response with rapid ...interaction.•The SnS2 flower-shaped gas sensor exhibits full-scale recovery at room temperature.•The underlying sensing mechanism for superior performance was explained.
Nanostructured SnS2 with enhanced edge sites was prepared and investigated the impact on NO2 gas molecules detection at room temperature (RT). SnS2 flower-like structure with exposed active sites provides more interaction channels for the NO2 gas molecules. The crystal orientation along with the (011) plane exhibits more active edge sites, thus enhancing the sensing performance of the flower-like structure. The fabricated SnS2 gas sensor showed more selective towards NO2 gas molecules. SnS2 flower-like structure provides more stability of 81.22% and 32.63% increased sensing response compared to the platelet-like structure. This result provides a pathway for the development of a practical room temperature NO2 gas sensor.
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•WO3/WS2 nanocomposites were successfully synthesized using facile hydrothermal method and subsequent annealing technique.•The gas sensing performance of WS2 and WO3/WS2 ...nanocomposites were investigated and shows excellent selectivity towards NO2.•WA-600 sensor showed a maximum response of 123% for 10 ppm NO2 with short response/recovery time of 11 s/ 163 s at RT.•The DFT calculations were performed to study the interfacial charge transfer between WO3/WS2 nanocomposite and gas molecules.•Gas sensing mechanism of WO3/WS2 nanocomposites were discussed.
In this article, we synthesized WO3/WS2 nanocomposites by facile hydrothermal synthesis followed by thermal annealing treatment and analysed its gas sensing properties. The thermal annealing process was carried out in different temperatures from 400 ℃ to 600 ℃ to form WO3/WS2 nanocomposite. During the thermal annealing process, the hydrothermally synthesized pure WS2 nanosheets undergo partial oxidation constructing WO3 on the surface developing active heterojunctions leading to increment in the sensing performance. The fabricated WO3/WS2 samples showed superior sensitivity and selectivity towards NO2 gas molecules. The pristine WS2 nanosheets showed a response of 26% towards 10 ppm of NO2 gas with a response and recovery time of 13 s /18 s, whereas WO3/WS2 nanocomposite prepared by annealing at 600 ℃ showed a maximum response of around 123% with a short response time of 11 s and recovery time of 163 s. The DFT calculations were performed to understand the gas sensing performance and interfacial charge transfer between the WO3/WS2 nanocomposite and gas molecules. Therefore, this study demonstrates that the indigenous heterojunctions contribute extensively to improving the gas detection capabilities of WO3/WS2 nanocomposites at room temperature.
Nitrogen dioxide (NO2) is one of the toxic gases produced by chemical industries, power plants, and vehicles. In this work, we demonstrate an inexpensive sensing platform for NO2 detection at room ...temperature (RT-32 °C) based on a charge transfer mechanism. Three-dimensional hierarchical SnS2 and SnS2/mesoporous TiO2 nanocomposites were synthesized via the solvothermal method. SnS2/20 wt% mesoporous TiO2 nanocomposites sample showed 245.4% enhanced response compared to pristine SnS2. The fabricated device exhibits excellent selectivity among all other interfering gases with one-month stability. The rapid response and enhanced response achieved were obtained for the minimum concentration of 2 ppm NO2. The formation of heterojunction between SnS2 and mesoporous TiO2 has a synergetic effect, providing more active sites and porous structures for the detection of NO2 gas molecules.
In recent times, the nanostructured materials of foreign metal ion doped ZnO photocatalysts acts as a hotspot in the research area of photocatalysis because of its non-toxic, cost-effective and ...environmental friendly behaviour. Sr-doped ZnO microspheres were synthesized by the hydrothermal method. In foreign metal ion-doped ZnO photocatalysts, Sr ions are uniformly distributed into ZnO lattice, which reflects the enhancement in the light absorption behaviour. Especially, 5% Sr-doped ZnO shifts the bandgap to visible region up to 422 nm. Sunlight-driven photocatalytic activity revealed that Sr (5%)-doped ZnO shows maximum degradation efficiency of 99%, 90%, and 93% on methylene blue, Rhodamine B, and ciprofloxacin, respectively. Further, the possible degradation mechanism was well-discussed with the help of the elemental trapping test.
Introduction
Naturopathy, Yoga and Dietary interventions are known to improve the quality of life in cancer patients. We aim to evaluate the effect of naturopathy interventions along with adjuvant ...chemotherapy in patients who underwent surgery for Adenocarcinoma of the Colon.
Methods
A total of 116 adult patients were randomised in to one of the two groups; the experimental group received naturopathy, Yoga and Dietary interventions and the control group received psycho-social counselling in addition to standard chemotherapy. Haematological, biochemical and psychological evaluations were performed at set intervals during a total period of eighteen months starting from the first cycle of adjuvant chemotherapy.
Results
Results showed that the overall hemoglobin (
p
< 0.0001) and carcinoembryonic antigen (CEA) (
p
= 0.0038) levels were statistically significant in patients on the experimental arm. The rest of the laboratory parameters, viz. total leukocyte count, platelet counts, and serum creatinine levels, for overall data was not statistically significant in both the groups. Psychological attributes such as anxiety, depression, symptom severity, and Functional Living Index: Cancer (FLIC) were found to be statistically significant (
p
< 0.0001) in the experimental subjects as compared with those in the control. On the whole, men benefited more than women from the study interventions.
Conclusions
We conclude that Yoga and Naturopathy interventions in addition to chemotherapy show improvement in overall functional life index along with improvement in haemoglobin in patients with stages II and III Adenocarcinoma of Colon.
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•ZnO/g-C3N4 were successfully synthesized using facile hydrothermal method.•ZnO/g-C3N4 nanocomposites were synthesized and the effect of g-C3N4 on NO2, sensing was investigated.•30 % ...- g-C3N4 shows enhanced response rate 1463 % (10 ppm NO2) at 180 °C.•Gas sensing mechanism of ZnO/g-C3N4 nanocomposites were discussed.
In this study, ZnO/g-C3N4 nanocomposites were synthesized using facile hydrothermal method by varying the concentration of g-C3N4 in 10 %, 30 % and 50 % weight percentage. The prepared nanocomposite samples were studied by various characterization techniques for morphological, structural, and elemental confirmation. The pristine ZnO microspheres show 229 % response towards 10 ppm NO2, whereas 30 % - g-C3N4 loaded ZnO nanocomposite shows drastic improvement in response rate around 1463 % (10 ppm NO2) at an operating temperature of 180 °C with rapid response and recovery time of 72 s and 145 s. The improved hybrid nanocomposite performance can be attributed due to the effective interface formation, increased surface area and enhanced gas adsorption active sites.
