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For a long time, metal oxide semiconductor (MOS) based gas sensors have been widely used in domestic, commercial, and industrial sectors to detect harmful gases. The performance of such sensors is significantly enhanced by appropriate doping of suitable materials into MOS such as ZnO and SnO2. This work showcases the design, analysis, and use of a Cu-doped ZnO (Cu: ZnO) film tailored for detecting traces of ethanol vapor at lower temperatures. Herein, various Cu: ZnO films have been fabricated on glass substrates using a spin coater followed by annealing at 600 for 1 hour in a muffle furnace. So-prepared samples have been characterized using X-ray diffraction, Energy Dispersive Analysis X-ray (EDAX), UV-visible spectrophotometer, and Scanning Electron Microscopy (SEM). The XRD analysis showed a polycrystalline nature with preferred orientation along (100) and (002) crystal planes. The morphology study showed their porous and granular surface structure. These films' elemental analysis demonstrated the good incorporation of Cu into the ZnO matrix. The UV-visible results showed a significant decrease in the band gap from 3.28 eV for undoped ZnO to 3.20 eV for Cu: ZnO films. Ultimately, as-prepared Cu: ZnO thin films were used for sensing ethanol vapor at temperatures ranging from 100 to 300 . The result showed a maximum sensitivity of 70.60 at a reduced temperature of 140 at 4% Cu: ZnO thin, which implies that Cu: ZnO is suitable for developing the gas sensors for upcoming future generations.

For a long time, metal oxide semiconductor (MOS) based gas sensors have been widely used in domestic, commercial, and industrial sectors to detect harmful gases. The performance of such sensors is significantly enhanced by appropriate doping of suitable materials into MOS such as ZnO and SnO2. This work showcases the design, analysis, and use of a Cu-doped ZnO (Cu: ZnO) film tailored for detecting traces of ethanol vapor at lower temperatures. Herein, various Cu: ZnO films have been fabricated on glass substrates using a spin coater followed by annealing at 600 for 1 hour in a muffle furnace. So-prepared samples have been characterized using X-ray diffraction, Energy Dispersive Analysis X-ray (EDAX), UV-visible spectrophotometer, and Scanning Electron Microscopy (SEM). The XRD analysis showed a polycrystalline nature with preferred orientation along (100) and (002) crystal planes. The morphology study showed their porous and granular surface structure. These films' elemental analysis demonstrated the good incorporation of Cu into the ZnO matrix. The UV-visible results showed a significant decrease in the band gap from 3.28 eV for undoped ZnO to 3.20 eV for Cu: ZnO films. Ultimately, as-prepared Cu: ZnO thin films were used for sensing ethanol vapor at temperatures ranging from 100 to 300 . The result showed a maximum sensitivity of 70.60 at a reduced temperature of 140 at 4% Cu: ZnO thin, which implies that Cu: ZnO is suitable for developing the gas sensors for upcoming future generations.

This paper compared the effects of A. indica plant proteins over chemical methods in the morphology of zinc oxide nanoparticles (ZnO NPs) prepared by a co-precipitation method, and ethanol sensing performance of prepared thin films deposited over a fluorene-doped tin oxide (FTO) bind glass substrate using spray pyrolysis technique. The average crystallite sizes and diameters of the grain-sized cluster ZnO NPs were 25 and (701.79 ± 176.21) nm for an undoped sample and 20 and (489.99 ± 112.96) nm for A. india dye-doped sample. The fourier transform infrared spectroscopy (FTIR) analysis confirmed the formation of the Zn–O bond at 450 cm−1, and also showed the presence of plant proteins due to A. indica dye extracts. ZnO NPs films exhibited good response (up to 51 and 72% for without and with A. indica dye-doped extracts, respectively) toward ethanol vapors with quick response-recovery characteristics at a temperature of 250 °C for undoped and 225 °C for A. indica dye-doped ZnO thin films. The interaction of A. indica dye extracts helps to decrease the operating temperature and increased the response and recovery rates of the sensor, which may be due to an increase in the specific surface area, resulting in adsorption of more oxygen and hence high response results.

Bio-synthesis of metal nanoparticles (CuNPs) is regarded as one of the recently developed, economic and environmentally benign method. In the present investigation, Copper nanoparticles were synthesized reacting garlic (Allium sativum) extract with Copper Sulphate (CuSO4∙5H2O) solution over magnetic stirrer at 80 °C for 1 hour. So-prepared CuNPs were studied by observing the color change at various time intervals. Further, the nanoparticles were characterized using UV-Visible spectroscopy, Energy Dispersive X-ray spectroscopy (EDX) and Fourier Transform Infrared spectroscopy (FTIR). The results of UV-Vis spectroscopy clearly showed presence of absorption peak at 595 nm which confirmed the formation of copper nanoparticles. Likewise, the EDX spectrum depicts the presence of optical band at 8 eV which is the characteristic peak of Copper consisting of 38.747 % by weight and FTIR spectra revealed presence of various phytochemicals possessing characteristic functional groups such as carbonyl and phenolic at the surface of CuNPs. Thus, natural products available in the garlic extract help in reduction and stabilization of Copper nanoparticles. The antibacterial activity of Copper nanoparticles was investigated against Gram +ve (Staphylococcus aureus) and Gram –ve bacteria (Escherichia coli) using Agarwell diffusion method. The results of antibacterial test showed that CuNPs were found to be much sensitive towards Gram –ve bacteria compared to gram +ve bacteria. BIBECHANA 17 (2020) 12-18

Bio-synthesis of metal nanoparticles (CuNPs) is regarded as one of the recently developed, economic and environmentally benign method. In the present investigation, Copper nanoparticles were synthesized reacting garlic (Allium sativum) extract with Copper Sulphate (CuSO4∙5H2O) solution over magnetic stirrer at 80 °C for 1 hour. So-prepared CuNPs were studied by observing the color change at various time intervals. Further, the nanoparticles were characterized using UV-Visible spectroscopy, Energy Dispersive X-ray spectroscopy (EDX) and Fourier Transform Infrared spectroscopy (FTIR). The results of UV-Vis spectroscopy clearly showed presence of absorption peak at 595 nm which confirmed the formation of copper nanoparticles. Likewise, the EDX spectrum depicts the presence of optical band at 8 eV which is the characteristic peak of Copper consisting of 38.747 % by weight and FTIR spectra revealed presence of various phytochemicals possessing characteristic functional groups such as carbonyl and phenolic at the surface of CuNPs. Thus, natural products available in the garlic extract help in reduction and stabilization of Copper nanoparticles. The antibacterial activity of Copper nanoparticles was investigated against Gram +ve (Staphylococcus aureus) and Gram –ve bacteria (Escherichia coli) using Agarwell diffusion method. The results of antibacterial test showed that CuNPs were found to be much sensitive towards Gram –ve bacteria compared to gram +ve bacteria. BIBECHANA 17 (2020) 12-18

The dependence of the structural, optical and electrical properties of the FTO thin films on the film thickness (276 nm - 546 nm), calcination environment, and low temperature plasma treatment were examined. The FTO thin films, prepared by spray pyrolysis, were calcinated under air followed by either further heat treatment under N2 gas or treatment in low temperature atmospheric plasma. The samples before and after calcination under N2, and plasma treatment will be represented by Sair, SN2 and SPl, respectively, hereafter. The thin films were characterized by measuring the XRD spectra, SEM images, optical transmittance and reflectance, and sheet resistance of the films before and after calcination in N2 environment or plasma treatment. The presence of sharp and narrow multiple peaks in XRD spectra hint us that the films were highly crystalline (polycrystalline). The samples Sair with the thickness of 471 nm showed as high as 92 % transmittance in the visible range. Moreover, from the tauc plot, the optical bandgap Eg values of the Sair found to be noticeably lower than that of the samples SN2. Very surprisingly, the electrical sheet resistance (Rsh) found to decrease following the trend as Rshair > RshN2 > RshPl. The samples exposed to plasma found to possess the lowest RshPl (for film with thickness 546 nm, the RshPl was 17 Ω/sq.).

Aluminium doped Zinc Oxide (AZO) seed layers were deposited on Fluorine doped Tin Oxide (FTO) substrates using a spin coating technique. These were then immersed in growth solutions of zinc nitrate, hexamethylenetetramine and distilled water to develop nanoplates of Zinc Oxide (ZnO). The nanostructures of ZnO grown on FTO were studied using x-ray diffraction techniques. Dye-sensitized solar cells (DSSC) were fabricated using two prepared electrodes, one of dye-loaded zinc oxide and another that was platinum coated. The electrolyte used was potassium iodide iodine solution. The performance of the assembled DSCCs was tested by drawing an IV curve. The results showed that the short circuit current and open circuit voltages were about 10 microamperes and 270 millivolts respectively. BIBECHANA 13 (2016) 23-28

Aluminium doped Zinc Oxide (AZO) seed layers were deposited on Fluorine doped Tin Oxide (FTO) substrates using a spin coating technique. These were then immersed in growth solutions of zinc nitrate, hexamethylenetetramine and distilled water to develop nanoplates of Zinc Oxide (ZnO). The nanostructures of ZnO grown on FTO were studied using x-ray diffraction techniques. Dye-sensitized solar cells (DSSC) were fabricated using two prepared electrodes, one of dye-loaded zinc oxide and another that was platinum coated. The electrolyte used was potassium iodide iodine solution. The performance of the assembled DSCCs was tested by drawing an IV curve. The results showed that the short circuit current and open circuit voltages were about 10 microamperes and 270 millivolts respectively. BIBECHANA 13 (2016) 23-28