Nanomaterials in biolubricant synthesis from vegetable oils: A systematic review of nanoadditives and nanocatalysts

Biomass-derived biolubricants offer an environmentally sustainable solution to shift from conventional mineral-based lubricants, addressing growing concerns over increasing carbon footprint, resource depletion, climate and environmental impact. This review systematically evaluates how application of various nanomaterials as both additives and heterogeneous catalysts improve the physiochemical properties, catalytic efficiency, tribological and rheological properties of biolubricants synthesized from edible and non-edible vegetable oils. A systematic literature search was conducted using Web of Science, Scopus and Google Scholar for studies published during 2015–2026 following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) framework. The identified records were screened and selected according to predefined inclusion and exclusion criteria, and a total of 104 studies were included in the final review. The analysis established that nano additives provide excellent lubricity to vegetable oils by reducing friction and wear, while nanocatalysts enable fruitful yield of biodegradable polyol esters. By combining nanotechnology and renewable feedstocks, this review contributes theoretical insights into the recent developments in production of sustainable and high performed biolubricants. Future research should focus on development of sustainable bio-derived nanoadditives, improved nanoadditive dispersion and surface functionalization, comprehensive life-cycle and environmental toxicity assessment, and scalable catalyst/nanoadditive recovery and reuse.