Fourier transform infrared spectroscopy

About: Fourier transform infrared spectroscopy is a research topic. Over the lifetime, 48250 publications have been published within this topic receiving 1134369 citations.

Investigation of mixed spinel structure of nanostructured nickel ferrite

Abstract: Single crystalline nickel ferrite (NiFe2O4) which has an inverse spinel structure is reported to exhibit a mixed spinel structure when its grain size is reduced to nanometer range. It is known that structural transformations in the nanosize regime are not akin to those of bulk crystals. Additionally, magnetic properties like superparamagnetism and contribution to it by surface layers are critically influenced by the synthesis route of the samples. In this article, we present an investigation on the structural transformation of nanostructured NiFe2O4 using x-ray diffraction (XRD), Mossbauer and magnetization measurements, and Fourier transform infrared (FTIR) and micro-Raman spectroscopy. Nanostructured NiFe2O4 samples were synthesized by a coprecipitation technique followed by thermal processing. Four samples having average grain sizes 13, 20, 26, and 51 nm were synthesized. XRD results confirmed the samples to be nanostructured NiFe2O4 and gave evidence for the mixed spinel structure of the samples of lo...

Mesoporous silica sphere-polysulfone mixed matrix membranes for gas separation.

Abstract: A series of mixed matrix membranes were prepared comprising polysulfone Udel matrix and ordered mesoporous silica spheres as filler with loadings varying between 0 and 32 wt %. The interaction between the filler and the polymer was studied by scanning and transmission electron microscopy, thermogravimetry, differential scanning calorimetry and dynamic mechanical analyses, N2 porosity, X-ray photoelectron spectrometry, and attenuated total reflectance Fourier transform infrared spectroscopy. All these characterizations allowed us to infer an optimum interaction based on both the penetration of the polymer chains into the mesoporosity of the silica spheres and the establishment of hydrogen bondings between the hydroxyl-rich surface and the aryl ether groups of the polymer. An optimum loading of 8 wt % was found in terms of H2/CH4 separation performance. In addition, the optimum membrane was tested for CO2/N2 separation.

Facile Photochemical Preparation of Amorphous Iridium Oxide Films for Water Oxidation Catalysis

Abstract: Light-driven decomposition of Ir(acac)3 spin-cast on a conducting glass substrate produces a thin conformal film of amorphous iridium oxide, a-IrOx. The decomposition process, which was carried out under an ambient atmosphere at room temperature and tracked by Fourier transform infrared (FTIR) spectroscopy, appears to proceed by way of a ligand-to-metal charge transfer (LMCT) process. The amorphous nature of the films is based on the lack of any observable Bragg reflections by powder X-ray diffraction techniques; the elemental composition was corroborated by X-ray photoelectron spectroscopy (XPS) measurements. The films are found to be excellent electrocatalysts for mediating the oxygen evolution reaction (OER) in acidic media, as evidenced by the onset of catalysis at 130 mV and a Tafel slope of 34 mV dec–1. These parameters enable current densities of 1 and 10 mA cm–2 to be reached at 190 and 220 mV, respectively. Exposing the films to higher temperatures (500 °C) renders a film of crystalline iridium o...