Alchornea laxiflora Bark Extract Assisted Green Synthesis of Platinum Nanoparticles for Oxidative Desulphurization of Model Oil

Abstract

This study reports the development of reliable and eco-friendly processes for the synthesis of platinum nanoparticles (PtNPs) via the reduction of chloroplatinic acid solution by the aqueous tree bark extract of Alchornea laxiflora at a reaction temperature of 100 °C. The mechanistic aspects of the reactions involved in the bioreduction process were proposed. The synthesized PtNPs were characterized by UV–visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), high resolution transmission electron microscopy (HRTEM), energy dispersive X-ray (EDX), and X-ray diffraction (XRD). The HRTEM image revealed that the PtNPs were in the size range of 3.68–8.77 nm with an average particle size of 5.93 ± 1.43 nm. The XRD pattern shows face centred cubic(fcc) phase structure while the FTIR analysis suggests that the obtained platinum nanoparticles were stabilized by the metabolites and protein through carbonyl and hydroxyl groups. Catalytic application of PtNPs for oxidative desulphurization of model oil (dibenzothiophene (DBT) dissolved in n-heptane) was investigated by comparing its catalytic potential with the conventional acetic acid catalyst. The results show that PtNPs has higher catalytic activity for oxidative desulphurization of model oil than acetic acid. Our results indicate that this eco-friendly, simple and cost-effective method will find useful applications in petroleum industry.