Modulating the electrochemical properties of mixed Prussian blue analogues for enhanced supercapacitor and electrocatalytic performance

Among various electrode materials, prussian blue analogues (PBAs) have attracted considerable attention due to their tunable composition and open three-dimensional (3-D) framework structure, enabling rapid ion transport. This paper synthesizes Co-Zn mixed PBAs with different metal ratios (C1:Z1, C2:Z1, C3:Z1, C1:Z2, and C1:Z3) using a simple co-precipitation method and evaluates their applications in supercapacitors and water splitting. Among these, C3Z1-PBA exhibits excellent electrochemical performance, with a maximum specific capacitance (C s ) of 339.84 Fg⁻¹ , superior to other compositions (C2Z1, C1Z1, C1Z2, and C1Z3). Furthermore, C3Z1-PBA exhibited outstanding bi-functional electrocatalytic activity, demonstrating 170 mV and 283 mV overpotentials and low Tafel slope of 50 mVdec −1 and 152 mVdec −1 at 10 mA cm-² for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), respectively. These results demonstrate that composition tuning of mixed PBAs effectively enhances their potential for advanced energy storage and water-splitting applications.