Kanika Anand

Optical studies of reduced graphene oxide thin films

We report here a simple and efficient method for fabrication of reduced graphene oxide (rGO) thin films. Graphite oxide can be completely exfoliated to produce aqueous colloidal suspensions of graphene oxide (GO) sheets by simple ultra-sonication. Graphene oxide thin films were reduced towards graphene by exposure to hydrazine vapor, ammonia vapor and microwaves. The samples were characterized using X-ray diffraction (XRD) and UV-Visible spectroscopy (UV-Vis).

Effect of Sn doping on morphology and ethanol sensing response of ZnO nanorods

In this work we are reporting the effect of doping of tin on the morphology and sensing response ZnO nanorods. We adopted chemical route to synthesize nanorods of ZnO and then 2% of Sn by weight was added at the time of reaction. To understand the structure we subjected the synthesized materials to XRD and FESEM. The addition of dopant has altered the morphology of ZnO, moreover it has also enhanced the sensing response for ethanol appreciably.

Gas sensing properties of zinc oxide thin films prepared by spray pyrolysis

Metal oxide semiconductors are widely employed as potential materials for the development of sensing devices for poisonous and inflammable gases. The change in resistivity of active material is exploited as a sensing parameter. A large volume of research work has been carried out in the last few decades on sensors and potential sensor materials. The advent of nanostructured materials has given a new impetus to the sensor research. Preparation and sensing response of zinc oxide thin films towards alcohol has been reported in this paper. Zinc oxide thin film has been prepared by using spray pyrolysis, using zinc acetate and methanol as the starting materials. The thin film was characterized for morphology and structure by using x-ray diffractometer (XRD) and field emission scanning electron microscope (FESEM) techniques. The results indicated that the ZnO particles are crystallized in the wurtzite hexagonal phase, which were well distributed in the films. Prepared zinc oxide thin film was exposed to different alcohols to check its gas sensing behaviour at different temperatures.Metal oxide semiconductors are widely employed as potential materials for the development of sensing devices for poisonous and inflammable gases. The change in resistivity of active material is exploited as a sensing parameter. A large volume of research work has been carried out in the last few decades on sensors and potential sensor materials. The advent of nanostructured materials has given a new impetus to the sensor research. Preparation and sensing response of zinc oxide thin films towards alcohol has been reported in this paper. Zinc oxide thin film has been prepared by using spray pyrolysis, using zinc acetate and methanol as the starting materials. The thin film was characterized for morphology and structure by using x-ray diffractometer (XRD) and field emission scanning electron microscope (FESEM) techniques. The results indicated that the ZnO particles are crystallized in the wurtzite hexagonal phase, which were well distributed in the films. Prepared zinc oxide thin film was exposed to differe...

Preparation and characterization of CNT-CeO2 nanocomposite

This paper reports decoration of CeO2 nanoparticles on multi-walled carbon nanotubes through a reflux process in which Ce (NO3) 3·6H2O serves as precursor and hydrazine hydrate (N2H4.H2O) as reducing agent. Successful deposition of cubic fluorite CeO2 nanoparticles onto multi-walled carbon nanotubes has been confirmed by x-ray diffraction (XRD), Raman spectroscopy, field-emission scanning electron microscopy (FE-SEM) and energy dispersive x-ray spectroscopy (EDS). It was found that CeO2 nanoparticles formed in the presence of CNTs were larger as compared to pure CeO2 nanoparticles. Raman analysis showed that CeO2 induced a decrease in the size of the carbon grain in the CNTs. A red shift from 460 cm−1 to 463 cm−1 for F2g mode of CeO2 has also been observed in Raman spectra of CNT- CeO2 nanocomposite as compared to pure CeO2. The CeO2 coated multi-wall carbon nanotubes (CNT-CeO2) nanocomposite would be a promising candidate for practical applications such as catalysis, sensing and power source applications.

Reduced graphene oxide/CeO2 nanocomposite with enhanced photocatalytic performance

In this work, reduced graphene oxide /cerium oxide (RGO/CeO2) nanocomposite was synthesized by in situ reduction of cerium nitrate Ce(NO3)3·6H2O in the presence of graphene oxide by hydrazine hydrate (N2H4.H2O). The intrinsic characteristics of as-prepared nanocomposite were studied using powder x-ray diffraction (XRD), Raman spectroscopy and field-emission scanning electron microscopy (FESEM). The photocatalytic degradation of methylene blue (MB) was employed as a model reaction to evaluate the photocatalytic activity of the RGO/CeO2 nanocomposite. The as-obtained RGO/CeO2 nanocomposite displays a significantly enhanced photocatalytic degradation of MB dye in comparison with bare CeO2 nanoparticles under sunlight irradiation, which can be attributed to the improved separation of electron-hole pairs and enhanced adsorption performance due to presence of RGO.

Acetone sensor based on zinc oxide hexagonal tubes

In this work hexagonal tubes of zinc oxide have been synthesized by co-precipitation method. For structural, morphological, elemental and optical analysis synthesized powders were characterized by using x-ray diffraction, field emission scanning microscope, EDX, UV-visible and FTIR techniques. For acetone sensing thick films of zinc oxide have been deposited on alumina substrate. The fabricated sensors exhibited maximum sensing response towards acetone vapour at an optimum operating temperature of 400°C.