Characterization of structural, optical and photocatalytic properties of silver modified hematite (α-Fe2O3) nanocatalyst

Abstract

In this paper, pure and silver doped (3% and 5%) α-Fe2O3 semiconductor nanoparticles were synthesized with co-precipitation from Fe2+, Fe3+ and Ag+-(doped samples) containing salts and subsequent thermal annealing at 400 °C of the precipitate. The structural, optical (absorption and emission), and surface electronic properties of α-Fe2O3 nanoparticles and the effect of silver doping were characterized by powder x-ray diffraction, Raman spectroscopy, diffuse reflectance spectroscopy, Fourier transform infrared spectroscopy, photoluminescence and x-ray photoelectron spectroscopy. Powder x-ray diffraction confirms the synthesis of pure alpha phase and mixed phases of iron oxide for undoped and Ag doped samples, respectively. The crystallite size and structural parameters were estimated with Debye Scherer and Williamson-Hall methods. The bandgap of iron oxide semiconductor nanoparticle samples was calculated by Tauc’s plot, showing the marginal increase in the bandgap with Ag content. To investigate the effect of Ag doping in the recombination rate of photogenerated charge-carrier, room temperature photoluminescence spectra of the nanoparticles were recorded at the excitation wavelength of 450 nm. Vibrational spectroscopy was utilized to find the chemical structure changes of iron oxide nanoparticles on Ag doping. Also, the dye degradation efficiency which includes surface adsorption and photocatalysis of dye with the iron oxide nanocatalysts is improved with Ag doping.