Influence of silver doping on the structure, optical and photocatalytic properties of Ag-doped BaTiO3 ceramics

Abstract

In this paper, an investigation on microstructure, optical, dielectric, photocatalytic and electrochemical properties of monodispersed Ag-doped BaTiO3 nanosized particles modified with different contents of silver (1, 3, 5 mol %) prepared by viable sol-gel technique has been carried out. The obtained samples exhibit tetragonal phase as confirmed by X-ray diffraction and Raman spectra. Using XRD data, the crystallite size of undoped and Ag-doped BaTiO3 nanoparticles (NPs) was found to be in the range of 46–54 nm, and have interplanar spacing of 0.283 nm as confirmed by HRTEM images. The characteristic peaks occurred at 309, 511 and 717 cm−1 in Raman spectra predicted the formation of tetragonal phase of barium titanate. The calculated band gap energy of BaTiO3 NPs was reduced from 3.87 to 3.47 eV by incorporating the silver ions (5% Ag). Intensity of photoluminescent peaks decrease with increasing Ag content indicating that recombination of electrons-holes was effectively restrained. Dielectric permittivity as well as loss of prepared nanosized particles have been decreased sharply in low frequency region and remained almost constant with low value in high frequency region. Photo-assisted-catalytic property of Ag-doped BaTiO3 NPs towards degradation of hazardous rhodamine B (RhB) dye under visible irradiation (λ ≥ 400 nm) was thoroughly investigated, and a remarkable photocatalytic activity of Ag (5%)-doped BaTiO3 NPs was observed as 79%. On this account, it is promoted as an excellent nanophotocatalyst for the degradation of organic pollutants. C–V analysis depicted that the diffusion coefficient of BaTiO3 NPs increases considerably with Ag incorporation, which is favourable for large–scale energy storage applications. BET analysis supported the claim of presently prepared materials to be an efficient photocatalyst as well as a potential material for efficient energy storage devices.