Ali A. Ensafi , E. Heydari-Soureshjani, A.R. Taghipour-Jahromi, B. Rezaei

Electrochimica Acta, Volume 395, 1 November 2021, 139192, https://www.sciencedirect.com/science/article/abs/pii/S0013468621014821

a b s t r a c t Herein, a novel core in hollow shell NiCo2O4 (CHS-NCO) metal-organic framework is designed using aurin tricarboxylic acid as a three-organic dental ligand for supercapacitor and hydrogen evolution application. The XRD results and FE-SEM images confirm the formation of NiCo2O4 and the spherical structure of NiCo2O4. TEM images demonstrated the core in the hollow shell structure of NiCo2O4 metal-organic framework derived. The as-prepared material shows the highest specific capacitance of 531 and 695 F g–1 in KOH and K3Fe(CN)6 (10.0 mmol L–1), respectively. Furthermore, the NiCo2O4/activated carbon batterylike supercapacitor device with a high operating potential window of 1.60 V is assembled and shown excellent energy density, power density, and durability electrolytes. The as-prepared battery-like supercapacitor device can light up three color LEDs for more than 60 min. This noticeable performance suggests the potential use of CHS-NCO material as a positive electrode for high-performance battery-like supercapacitors and electronic devices. Also, the HER electrocatalyst shows the Tafel slope of 69 and 81 mV dec–1 for Pt and graphite counter electrode, respectively. The current density of 10 mA cm–2 achieves at the potential of -0.17 and -0.38 V (vs. RHE) for Pt and graphite counter electrode, respectively, and the electrode material exhibits high long-cycle life acidic media. So it is a good candidate for HER.

Keywords: Metal-organic framework Aurin tricarboxylic acid Core in hollow shell structure Battery-like supercapacitor Hydrogen evolution reaction