Revolutionizing biodiesel production: A breakthrough synthesis and characterization of bismuth ferrite nanocatalysts for transesterification of palm and waste cooking oil

•The present work deals with the successful synthesis of a novel heterogeneous bismuth ferrite nanocatalyst (BiFeO3) using kappa-carrageenan polysaccharides.•The BiFeO3 nanocatalyst demonstrated exceptional catalytic activity during the transesterification of palm cooking oil.•The abovementioned processes with different reaction parameters were investigated in batches.•The effects of oil-to-methanol molar ratio, catalyst amount, reaction time, and temperature on the production of FAME were investigated.•Approximately 98% FAME content was achieved using oil and methanol at a molar ratio of 1:15. The present work deals with the successful synthesis of heterogeneous bismuth ferrite nanocatalysts (BiFeO3) using kappa-carrageenan polysaccharides to study the efficient transesterification of palm cooking oil for biodiesel production. The optimized size of pristine BiFeO3 obtained was 95.8 nm, at a molar ratio of (Bi: Fe; 1:2) with a 1 % carrageenan biotemplate and calcined at 823 K for 2 h. The nanocatalysts have been producing high thermal stability, and X-ray diffraction (XRD) analysis showed the rhombohedral crystalline phases. The BiFeO3 nanocatalysts demonstrated outstanding catalytic performance during the transesterification of palm and waste cooking oils. The abovementioned processes with different reaction parameters for the production of fatty acid methyl ester (FAME) were investigated in batches. The effects of the catalyst dosage, temperature, time, and molar ratio (oil/methanol) have been conducted. A maximum FAME yield of 98% was achieved using optimized conditions: oil and methanol at a molar ratio of 1:15, and BiFeO3 with a 7 wt% catalyst dosage in 2 h at 353 K. The results indicated high chemical stability of the catalyst after five consecutive cycles with the same catalytic performance and proved to be a suitable catalyst for the production of biodiesel with high reaction rates and low catalyst usage.