Fabrication of GdFO3-Carbon nanotubes nanocomposites for enhanced photocatalytic applications

Abstract

Perovskite type unsubstituted GdFeO3 and Cr-substituted GdCrxFe1-xO3 nanoparticles were synthesized by facile co-precipitation method. X-rays diffraction analysis (XRD) was carried out to confirm the structural parameters of all compositions of GdCrxFe1-xO3 nanoparticles. XRD confirmed the orthorhombic structure. The crystallite size as determined by Scherrer formula was found in the range 18–20 nm. Scanning electron microscopy (SEM) was used to determine the morphological appearance which revealed the spherical morphology. The particles size as determined from SEM images was found in the range 50–60 nm. Fourier transforms infrared spectroscopy showed the purity level of the prepared GdFeO3 nanoparticles. Typical FTIR spectrum showed the band positions at 416 cm−1, 529 cm−1 and 909 cm−1. These bands corresponded to Fe–O, Gd–O etc. Ultraviolet visible analysis was carried out to characterize the absorption properties of the prepared powdered sample. It was observed that the absorption maxima at 650 nm and estimated band gap value of GdFeO3 was 1.9 eV thus it is active in visible region. For application study, calcined GdFeO3 nanoparticles was added as a photocatalyst into dye contaminated water. It was active when hydrogen peroxide (H2O2) was added to RhB and GdFeO3 system. Degradation efficiency was 64%. Composites with carbon nanotubes were synthesized and its photocatalytic activity was observed under same condition, however owing to higher surface area it showed 20% more photocatalytic efficiency as compared to GdFeO3 NPs. Revealed by BET analysis, surface area of GdFeO3-CNTs composites was about 30.9515 m2/g while that of pure GdFeO3 was about 8.667 m2/g. The comparison of activity of GdFeO3 photocatalyst was made with that GdFeO3-CNTs composites photocatalyst and hydrogen peroxide system which showed boosted photocatalytic activity up to about 94%.