Harnessing the Potential of UU 200/Bi4O8 Nanocomposite to Optimize Energy Efficiency in Supercapacitor and Electrocatalysis Application

In the pursuit of sustainable energy solutions, the spotlight shines on the advancement of effective energy storage systems and green hydrogen production. In this work, UU 200 (UU: Uppsala University) metal–organic framework (MOF)/bismuth oxide (Bi₄O₈), termed the UU 200/Bi₄O₈ nanocomposite, has been synthesized and utilized as an electrode material for supercapacitor applications and an electrocatalyst for hydrogen evolution reaction (HER). XRD, Raman, FT-IR, and XPS tests showed that the UU 200/Bi₄O₈ nanocomposite was successfully formed. The SEM and TEM images revealed that the UU 200/Bi₄O₈ nanocomposite exhibits a mixed rod and spherical structure. The supercapacitor performance of pure UU 200 and UU 200/Bi₄O₈ nanocomposite has been examined through cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance (EIS) measurements. Interestingly, the UU 200/Bi₄O₈ nanocomposite delivered a maximum specific capacitance value of 220 F g⁻¹ at 1 A g⁻¹. Furthermore, the UU 200/Bi₄O₈ nanocomposite potential was extended beyond its energy storage capability to the electrocatalytic HER process. The electrocatalytic HER performances were assessed through linear sweep voltammetry (LSV), CV, chronoamperometry (CA), and EIS analysis. The overpotential (ɳ) of 130 mV and the Tafel slope value of 131 mV dec⁻¹ indicate the UU 200/Bi₄O₈ nanocomposite supremacy in advanced applications. The UU 200/Bi₄O₈ nanocomposite electrode has excellent supercapacitor and water-splitting performance, allowing it to acquire green energy for future energy needs.