Enhanced photocatalytic applications of Ni-doped MoO₃ nanoparticle synthesized via green combustion process using Garcinia cambogia seed powder

In this study, molybdenum oxide NPs (MoO₃ NPs) and nickel-doped molybdenum oxide NPs (Ni-Doped MoO₃ NPs) are synthesized using Garcinia cambogia seed powder as a sustainable biofuel source. We synthesized MoO₃ NPs at different fuel ratios (0.25, 1:0.5, and 1:1) and investigated Ni-doped MoO₃ NPs at different nickel doping levels (2 wt%, 4 wt%, 6 wt%, and 8 wt%). An environmentally friendly synthesis of Ni-doped MoO₃ NPs with improved photocatalytic performance can be achieved using Garcinia cambogia seed powder, which is recognized as a renewable biofuel source. For optical and surface analysis, X-ray diffraction spectroscopy, Fourier transform infrared (FTIR), UV spectroscopy, photoluminescence spectroscopy, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) were used for characterization. The crystal structure of MoO₃ NPs with an average crystallite size of 20 nm was confirmed by XRD, FTIR identified Mo bonds and UV–visible spectroscopy shows a band gap of 4.5 eV for Ni-doped MoO₃ NPs. EDX analysis of SEM images with photoluminescence revealed no lattice defects and XPS determined the chemical state of the elements and the material composition of the NPs. Under photocatalytic conditions with UV light, the MoO₃ NPs were observed to efficiently degrade the dye methylene blue. A cubic wurtzite structure with increased crystallinity was observed in nickel-doped MoO₃ NPs. Moreover, Ni-doped MoO₃ NPs exhibited superior photocatalytic performance when exposed to UV light, confirming successful nickel doping by FTIR and XPS. Defect states were identified by photoluminescence and their size and morphology were investigated by SEM. This study highlights a nickel-doped MoO₃ NPS with exceptional photocatalytic properties and Garcinia cambogia seed powder with potential for environmentally friendly synthesis.