Green synthesis of LaCrO3 powder mediated by the extract of the Amazon rainforest native plant Himatanthus drasticus (Mart.) Plumel and their photocatalytic activity

Abstract

Lanthanum chromite (LaCrO3) powder was successfully synthesized by plant-extract-assisted sol–gel method using milk of Janaguba (Himatanthus drasticus (Mart.) Plumel) as an eco-effective chelating agent. X-ray diffraction (XRD), Rietveld refinement, Fourier-transform infrared spectroscopy (FT-IR), and Scanning electron microscopy (SEM) analysis revealed an orthorhombic crystalline structure, with average crystallite and particle sizes of ~40 and ~640 nm, respectively, confirming the obtaining of LaCrO3 powder. UV–vis absorption spectrum reveals a band with a well-defined maximum in the range of 230–350 nm, with an optical band-gap energy value of 3.33 eV. The photocatalytic degradation efficiency of MB in the presence of LaCrO3 as photocatalyst after 120 min of illumination (in low light intensity of 2.87 Wcm−2) was 6.3%. Therefore, our study provides preliminary evidence that the LaCrO3 powder is a potential photocatalyst for MB dye degradation, a pigment widely used by the textile industry that generates large amounts of effluents to be treated. Finally, the present synthesis proposal presents a cheap and eco-friendly alternative for the production of LaCrO3 powder.