Nanoparticles-suspended biodiesel and its blends in compression ignition engines: a bibliometric analysis of research trend and future outlook

The bibliometric analysis of nanoparticle-suspended biodiesel engine performance research (NSBEPR) has been presented. Publication data on NSBEPR extracted from the Scopus (R) database from 2009 to 2021 were analyzed using VOS viewer (R). The network of co-authorship of participating countries and organizations, citation counts of scientific papers and journals, and co-occurrence of author keyword were analyzed to study the research trend, hotspot, temporal distribution, and future direction. With a sum of 260 scientific publications used in this study, the network analysis revealed India (208 articles and 4514 citations) and the University of Malaya (12 articles and 700 citations) were the most productive country and institution, respectively, concerning NSBEPR. The most cited paper and journal were the work of Shaafi and Velraj (2015) and "Fuel" with 208 and 1256 citations, respectively. The utilization of metal oxides (Al2O3 and CeO2) as nanoparticles, waste (cooking oil) and edible (soybean) oils as biodiesel feedstocks, biodiesel blend with diesel (at 20%) as fuel, and the investigation of the same in direct ignition diesel engines were observed as the research hotspots. Future research focused on the deployment of magnetic conditioning, green and novel nanoparticles, hybrid and novel biodiesel, hydrogen, spent tire, and plastic oils as fuel additives.