Synthesis, structural, FTIR and UV–vis spectroscopic, thermal and dielectric studies of magnesium ion doped nickel pyrophosphate nano-particles

Abstract

Nickel pyrophosphate finds applications in energy storage device, super-capacitor, nano scale devices, catalyst for H2 generation and also used as a photo-catalyst for dye degradation. Pure and 2 %, 5 % and 10 % Mg ion doped Ni2P2O7 nano particles are synthesized through a surfactant mediated approach. In the Powder XRD pattern the broadening confirms the nano-structured nature and the monoclinic structure is found for pure α- Ni2P2O7 and Mg doped nano particles. The EDAX analysis confirms the elemental composition. The TEM study confirms the nano-size of the synthesized pure and doped samples, which are having dimensions in the range from 7.19 nm to 25.99 nm. The presence of stretching vibrations of POP and PO3 confirmed by the FT-IR study. The UV-NIR absorption spectroscopy of pure and Mg ion doped Ni2P2O7 samples over the spectral range of 210–1200 nm is carried out and the direct optical energy band gap is found to decrease as the content of Mg increases in the samples. TGA confirms the presence of water molecules in the samples and their highly stable nature. The dielectric study is conducted from 100 Hz to 10 MHz range at different temperatures from 50 °C to 100 °C. The dielectric constant and loss factor decrease with increasing frequency. The a.c. conductivity increases with increasing frequency and follows the Jonscher’s Power law. The models for a.c. conduction mechanisms are proposed based on Jonscher’s parameters.