عنوان المقالة:Structural, optical and electrical properties of sol–gel prepared mesoporous Co3O4/SiO2 nanocomposites
جمعه عبدالجواد محمد على | Gomaa A. M. Ali | 20072
نوع النشر
مجلة علمية
المؤلفون بالعربي
Gomaa A.M. Ali, Osama A. Fouad, Salah A. Makhlouf
الملخص العربي
Structures, optical and electrical properties of Co3O4/SiO2 nanocomposites are reported. Well crystalline Co3O4 nanoparticles embedded in an amorphous SiO2 matrix is formed, and confirmed by XRD and FTIR measurements upon calcination of gel precursors up to 800 °C. The obtained nanocomposites have high surface area ∼126–312 m2 g−1, and the Co3O4 particle size was ∼7–15 nm. The optical properties of the Co3O4/SiO2 nanocomposites indicate the presence of two energy gaps; both of them are smaller than those reported for the Co3O4 bulk phase. The first is varied from 1.32 to 1.44 eV and the second one is varied from 1.76 to 1.87 eV depending on the particles size. DC conductivity was measured in the temperatures range 300–673 K. The activation energy for DC conduction varies with particle size. The conduction mechanism was suggested to be through small polarons and variable range hopping mechanisms, at high and low temperatures respectively.
تاريخ النشر
05/12/2013
الناشر
Journal of Alloys and Compounds
رقم المجلد
579
رابط DOI
https://doi.org/10.1016/j.jallcom.2013.07.095
الصفحات
606-611
رابط الملف
تحميل (721 مرات التحميل)
رابط خارجي
http://www.sciencedirect.com/science/article/pii/S0925838813017209
الكلمات المفتاحية
Cobalt oxide/silica, Nanocomposite, Mesoporous structure, Optical properties, Electrical conductivity
رجوع