Visible-Light Induced Photodegradation of Methyl Orange via Palladium Nanoparticles Anchored to Chrome and Nitrogen Doped TiO2 Nanoparticles

Abstract

The Cr/N–TiO2 and Pd/Cr/N–TiO2 were synthesized via sol–gel and photoreduction techniques respectively. Subsequently, optimized samples were utilized as photocatalyst agent to degradation of methyl orange under visible light. Tetraisopropyl orthotitanate, chromium nitrate Cr(NO3)3·9H2O, palladium nitrate Pd(NO3)2 and triethylamine was used as precursors. The crystalline structure, morphology, particle size, absorbance, band-gap and chemical structure of samples were characterized by X-ray diffraction, diffuse reflectance spectra, scanning electron microscopy, energy dispersive spectrometry and Fourier transform infrared (FT-IR) techniques, respectively. Results demonstrate that nature and amount of dopant affect photocatalytic activity. For degradation of methyl orange, optimum concentration of Cr3+ and Pd was obtained 2% and 10% respectively. After 240 min, under visible light, photocatalytic efficiency of 2%Cr/2%N–TiO2 was obtained 97.59%. Also, after 75 min, under ultra violet light, photocatalytic efficiency of 10%Pd/2%Cr/2%N–TiO2 was obtained 97.56%.