Green synthesized, photocatalytic Co-doped MoO3 nanospheres for wastewater treatment

Abstract

This research has utilized a facile green synthesis technique, being simple and economical to produce pure molybdenum oxide (MoO3) and cobalt-doped molybdenum oxide (Co:MoO3) nanospheres with varying concentration of Co (1, 2, 3, 4, and 5 wt%). Moringa oleifera leaves as a sustainable and novel precursor were utilized for this green synthesis approach because of their special phytochemical composition, which provided both a reducing and stabilizing effect as well as helping to create nanospheres that were safe for the environment. These precursors demonstrate their cooperative role in mediating a safe and efficient pathway for the synthesis of customized nanomaterials without harming the environment. The as fabricated nanomaterials were studied via various characterization techniques like X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), Raman, Fourier transform infrared (FTIR), and ultraviolet–visible (UV–vis) spectroscopies. XRD analysis has revealed the successful formation of Co:MoO3 nanomaterials with particle size in the range of 70-40 nm. SEM analysis has shown the morphology of the nanomaterial to be like nanospheres, and EDX analysis has confirmed the presence of only Mo, O, and Co in the as fabricated samples. It has been established that there are vibrational linkages corresponding to oxygen and molybdenum using FTIR and Raman spectroscopy. UV–vis analysis has revealed a significant decrease in the energy band gap of MoO3 as 3.12 eV–2.85 eV for 4 wt % Co content. The highest-quality structural and optical characteristics are observed at a concentration of 4 wt% Co. The as synthesized nanospheres (4%Co:MoO3) are used as photocatalyst against the decolonization of methylene blue (MB) and methyl orange (MO) and have shown excellent efficiencies i.e 97.13 % and 97.85 %, respectively. Furthermore, this sample still remained stable even after four cycles of use thus showing its excellent photocatalytic ability by revealing 82.5 and 83.2 % degradation efficiencies against MB and MO dyes, respectively. Overall, our work shows that by breaking down organic contaminants, Co-doped MoO3 nanospheres are a viable photocatalytic agent for treating wastewater.