Novel Copper Oxide Phyto-Nanocatalyst Utilized for the Synthesis of Sustainable Biodiesel from Citrullus colocynthis Seed Oil

The green chemistry method for nanocatalyst synthesis along with environmentally feasible non-edible sources are promising alternatives to fossil fuels. The current study focuses on the synthesis of copper oxide phyto-nanocatalyst and the identification of a new renewable feedstock, Citrullus colocynthis, to reduce environmental pollution. The highest biodiesel yield (95%) was obtained under optimum conditions of a 1:8 oil-to-methanol ratio and reaction temperature of 85 °C for 120 min with a 0.365 wt% catalyst concentration. The phyto-nanocatalyst was synthesized using seed oil cake after extracting oil with the salt of copper (copper oxide). The catalyst was then subjected to various analyses, namely, EDX, FT-IR, SEM, and XRD. The catalyst was proved to be efficient and effective after being reused five times and still there was a very small difference in biodiesel yield. All the analyses also show sustainable and stable results. Thus, copper oxide phyto-nanocatalyst with non-edible Citrullus colocynthis proved to be highly effective, sustainable, and a better alternative source to the future biodiesel industry.