Structural transition and photoluminescence behavior of (V2O5)1-x (Ag0.33V2O5)x (x = 0 to 0.1) nanocomposites

Abstract

The two phase (V2O5)1-x(Ag0.33V2O5)x (x = 0, 0.05, 0.075 and 0.1) nanocomposites were synthesized through one step hydrothermal process. The X-ray diffraction followed by two phase Rietveld refinement confirms the crystallization of V2O5 and Ag0.33V2O5 phases in the Pmmn (orthorhombic) and C21 (monoclinic) symmetry respectively without any impurity phase. Furthermore, the FE-SEM, EDX, PL, UV–vis and XPS characterization were carried out for microstructural, optical and chemical studies. The formation of Ag0.33V2O5 nano-belts with average length and width of 3–4 μm and 40–50 nm respectively, were observed in the electron micrograph. Moreover, the XPS study confirms the constituent element are in expected oxidation states with Vanadium in only + 5 (V+5) for V2O5 and in mixed states (V+5 and V+4) for 10 % Ag0.33V2O5 nanocomposite. The photoluminescence spectra of these nanocomposite depicts two broad emission peaks located around 570 nm and 707 nm due to indirect inter-band and mid-state energy states transitions, respectively. PL also prove the increase in oxygen vacancies by loading of Ag in V2O5 matrix. The optical absorption of Ag0.33V2O5 represents a decrease in the energy band gap (2.10–1.97 eV) by adding Ag concentration in the V2O5, which also proved the semiconductor to metal transition (SMT).

Keywords

• Hydrothermal
• Nanocomposites
• Nanobelts
• Band-gap
• Optical absorption
• Phase transition