No abstract

No abstract

No abstract

No abstract

The current study examines the gas sensing properties of the fabricated material Al3+ modified ZnO. The material was fabricated by using co-precipitation technique. Here, sodium hydroxide was used as precipitating material to precipitate zinc as zinc hydroxide to convert it finally into ZnO. The insitu doping method was adapted to doped aluminum through ZnO lattice. The material was characterized by means of several characterization techniques. The X-ray diffraction (XRD) instrument utilized for structural investigation of the prepared material. The mean particle size estimated 28 nm using the Debye-Scherer equation. Scanning electron microscopy (SEM) was utilized for surface and topographic properties of the prepared material, while energy dispersive x-ray spectroscopy (EDX) was utilized to get atomic weight percentage of elements. The ultra violet diffuse reflectance spectroscopy (UV-DRS) was used to find the energy band gap of modified ZnO. The hexagonal crystal lattice of the materials was confirmed from transmission electron microscopy (TEM) analysis. Thick films of Al3+ doped ZnO made using a screen printing technology. The developed thick film sensor of Al3+ doped ZnO was utilized to sense certain harmful gases such as toluene vapors (TV), LPG, petrol vapors, CO2 and CO. The material showed considerable response for CO and LPG at 500 ppm gas concentration with 85.20% and 76.23% gas response at 90°C and 120°C respectively. The other gas sensing characteristics of the materials was also examined for the fabricated Al3+ doped ZnO sensor such as response and recovery, reusability, ppm variation and gas response. From overall study it was observed that fabricated sensor Al3+ doped ZnO is reliable, and very rapid to detect the carbon monoxide vapors and liquefied petroleum gas vapors (LPG) at moderately high temperature and low gas concentration. The built sensor’s gas sensing mechanism was assessed to detect CO and LPG.

No abstract

In the present investigation the material Co3O4 nanoparticles were prepared by co-precipitation method, while graphitic carbon nitride (g-C3N4) was prepared by direct heating of melamine. The nanocompositeg-C3N4- Co3O4were prepared by stoichiometric mixing and direct heating in porcelain boat followed by calcination. The prepared nanomaterials were characterized by various techniques. These both materials were characterized by XRD to get structural parameters and to confirm the average particle size of prepared nanomaterial. The scanning electron microscopy(SEM) was carried out to get surface characteristics of prepared materials. The energy dispersive spectroscopy was conducted to get elemental composition prepared material Co3O4and g-C3N4- Co3O4 .The transmission electron microscopy (TEM) was conducted to get lattice information of prepared material. While magnetic properties of both the material were investigated by means of vibrating sample magnetometer (VSM), since cobalt oxide is a ferromagnetic material. The surface area was confirmed from Brunauer-Emmett-Teller (BET) study. The g-C3N4- Co3O4nanocomposite has found enhanced surface areaof 78.48 m2/g in comparison to the sole Co3O4nanomaterial (55.23 m2/g). Both these prepared materials were utilized in photocatlytic degradation of CarbolFuchsin (CF) dye. The various parameters related to optimization of photocatlytic degradation of dyes were investigated in detail. The carbon nitride mediated cobalt oxide material is found to be very effective for degradation of CF dye and almost 97% of dye was successfully decomposed by the g-C3N4- Co3O4nanocomposite. The reusability test confirms that the prepared g-C3N4- Co3O4nanocomposite is very efficient in degradation of CF dye in multiple cycles with 110 minutes of contact time.

In the present investigation we have fabricated the cerium dioxide (CeO2) nanoparticles by green route. While preparing the cerium dioxide nanoparticles by co-precipitation method, Neem leaf extract mixed into the precursor of cerium. The synthesized nanoparticles of CeO2 were used for the preparation of thick film sensor by using screen printing strategy. The fabricated CeO2 sensor was characterized by XRD, SEM, EDS and TEM techniques. The structural characteristics investigated by x-ray diffraction technique (XRD). XRD confirms the formation of cubic lattice of CeO2 material. The surface, texture, porosity characteristics were investigated from SEM analysis, while chemical composition of the material was analysed by EDS technique. The transmission electron microscopy (TEM) confirms the formation cubic lattice of the cerium dioxide material. The thickness of the films was calculated from mass difference method, the prepared film sensors belong to thick region. The fabricated material CeO2 sensor was applied as gas sensor to sense the gases such as LPG, petrol vapors (PV), toluene vapors (TV) and CO2. The CeO2 sensor showed excellent gas response for LPG and PV, nearly 93.20 % and 78.23 % gas response. The rapid response and recovery of the prepared sensors was observed at the tested gases. CeO2 material also employed for antibacterial study at several pathogenic organism such as pseudomonas, staphylococcus aureus and salmonella typhae. From antibacterial study it was observed that the material is capable of inhibiting the growth of these pathogenic microbes.