Designing of efficient CoLa₂O₄/V-Ag-MOF hybrid electrode for energy storage, hydrogen evolution reaction, and chemical sensors

The low conductivity, specific capacity, and stability of metal–organic frameworks (MOFs) pose significant challenges for their practical application in energy storage devices. This is being overcome by synthesizing their unique variants and composites with other energy storage materials. In this wake, we have synthesized CoLa₂O₄ via the hydrothermal method for doping in hydrothermally synthesized V-Ag-MOF. Various characterization techniques like SEM, XRD, XPS, BET, and BJH were utilized to investigate the morphological, structural, and compositional properties of the CoLa₂O₄/V-Ag-MOF composite in detail. When evaluated at 3 mVs⁻¹, the hybrid CoLa₂O₄/V-Ag-MOF electrode, benefitting from the synergetic effects of both materials performed remarkably well exhibiting an exceptional Q_s of 1,313 Cg⁻¹. For the real device testing, the CoLa₂O₄/V-Ag-MOF//AC demonstrated a specific capacity of 373.5 Cg⁻¹ at 1.1 Ag⁻¹. Moreover, the hybrid supercapacitor device obtained an outstanding energy density (E_d), measuring 83.1 Wh kg⁻¹, and an impressive maximum power density (P_d) of 4160 W kg⁻¹. Furthermore, the CoLa₂O₄/V-Ag-MOF nanocomposite electrode is also used as an electrochemical sensor to detect the H₂O₂ up to a small level of 1 H₂O₂ mm⁻¹ with high accuracy. The material CoLa₂O₄/V-Ag-MOF also exhibited impressive catalytic performance by revealing the lowest overpotential of 43 mV and a Tofel slope of 39 mV dec^-1 during HER application. The multifunctional CoLa₂O₄/V-Ag-MOF nanocomposite electrode material has the potential to offer novel ideas for hybrid energy storage as well as bio-sensing and hydrogen evolution devices.