Solvent-Free Combustion-Assisted Synthesis of LaFe0.5Cr0.5O3 Nanostructures for Excellent Photocatalytic Performance toward Water Decontamination: The Effect of Fuel on Structural, Magnetic, and Photocatalytic Properties

The present study reports the synthesis of nano-crystalline LaFe0.5Cr0.5O3 via a solvent-free combustion method using glycine, poly(vinyl alcohol), and urea as fuels, with superior photocatalytic activity. Rietveld refinement and powder X-ray diffraction data of nanomaterials demonstrate the existence of an orthorhombic phase that corresponds to the Pbnm space group. The crystallite size of nanoperovskite samples lies in the range of 20.9-36. 4 nm. The Brunauer-Emmett-Teller (BET) surface area of the LaFe0.5Cr0.5O3 fabricated using urea is found to be higher than that of the samples prepared using other fuels. The magnetic measurements of all samples done using a SQUID magnetometer showed a dominant antiferromagnetic character along with some weak ferromagnetic interactions. The optical band gap of all nanosamples lies in the visible range (2-2.6 eV), making them suitable photocatalysts in visible light. Their use as a photocatalyst for the degradation of the rhodamine B dye (model pollutant) is studied, and it has been observed that the catalyst fabricated using urea shows excellent degradation efficiency for rhodamine B, i.e., 99% in 60 min, with high reusability up to five runs. Additionally, the degradation of other organic dyes such as methylene blue, methyl orange, and a mixture of these dyes (rhodamine B + methylene blue + methyl orange) is also investigated with the most active photocatalyst, i.e., LFCO-U, to check its versatility.

Automated summary

The present study synthesized nano-crystalline LaFe0.5Cr0.5O3 with superior photocatalytic activity using a solvent-free combustion method. X-ray diffraction data confirmed the presence of an orthorhombic phase and the crystallite size ranged from 20.9 to 36.4 nm. The LaFe0.5Cr0.5O3 prepared with urea showed a higher surface area compared to other fuels. The material exhibited antiferromagnetic behavior and had an optical band gap suitable for visible light photocatalysis. The catalyst fabricated with urea showed excellent degradation efficiency for rhodamine B and could be reused multiple times for degradation.