Impact of Surface Modulation of Two-Dimensional Ni-MOF and Its Derivatives on Electrochemical Energy Storage and Electrocatalytic Performance

Abstract

This research introduces an innovative approach to enhancing materials for supercapacitors, as well as hydrogen evolution reactions. The study involves synthesizing two-dimensional nickel metal–organic frameworks on nickel foam and the oxide-based materials derived from them and investigating the influence of various surfactants on structural architecture. Among the surfactants, sodium dodecyl sulfate (SDS) displayed the most effective outcomes. The SDS-assisted Ni-MOF-derived NiO demonstrated better electrochemical characteristics when served as one of the electrodes in a supercapacitor exhibiting a high specific capacity of 841.2 C·g^–1 (equivalent to 1682.4 F·g^–1) when tested at 1 A·g^–1, and maintained 92.9% of this capacity after 5000 charge–discharge cycles. This represents significant improvements over surfactant-free materials, with a 26% increase in specific capacitance. In an asymmetric supercapacitor setup, the material demonstrated an impressive energy density (67.89 Wh·kg^–1) coupled with a power density of 750 W·kg^–1. When applied to the hydrogen evolution reaction, it reached 10 mA·cm^–2 with an overpotential of only 87 mV. It also showed a consistent performance over 24 h. The findings highlight how surfactant-assisted synthesis of Ni-MOF and subsequent derivation resulted in interlinked nanoparticle assemblies arranged in a hierarchical, blossom-like superstructure, which significantly enhances both electrochemical and hydrogen evolution performance. The study underscores the potential of tailored MOF synthesis in developing advanced materials for sustainable energy applications.