Novel bio-chelating agent-assisted eco-friendly synthesis of Sr0.9X0.1CoO3−δ (X = Ba, Ce) perovskite electrodes for supercapacitor applications

Abstract

The current work pioneers the synthesis of a novel composition of Sr_0.9X_0.1CoO_3−δ (X = Ba, Ce) perovskite electrode materials for supercapacitors through an innovative semi-green route, utilizing lemon powder as the bio-chelating agent. The synergy between the biomolecules and organic citric acid in lemon powder resulted in minimal impurities and enhanced the crystallinity of the desired perovskite electrodes. XRD analysis confirmed the cubic perovskite structure of all Sr_0.9X_0.1CoO_3−δ (X = Ba, Ce) perovskite electrodes synthesized via both semi-green and chemical approaches. Notably, samples synthesized through the semi-green approach exhibited better crystallinity with no secondary phases. Microstructural analysis revealed a dense and agglomerated morphology for all samples, while EDX analysis confirmed the elemental composition with no prominent impurities. FTIR analysis confirmed the presence of identical functional groups in samples synthesized through both routes. Electrochemical studies demonstrated the highest specific capacitance of 1176.36 F g⁻¹ and excellent electrochemical stability, with 88.2% capacity retention after 5000 galvanostatic charge–discharge cycles for Sr_0.9X_0.1CoO_3−δ (X = Ce) synthesized through the semi-green route. Meanwhile, Sr_0.9X_0.1CoO_3−δ (X = Ba) also exhibited a reasonable specific capacitance. These findings confirm that the novel perovskite composition Sr_0.9X_0.1CoO_3−δ (X = Ba, Ce) can be successfully utilized for supercapacitor applications and that the innovative semi-green route can also be employed for the efficient synthesis of perovskite materials, ensuring minimal ecological impact and reduced impurities compared to conventional chemical and green synthesis routes.