Enhanced Photocatalytic and Electrochemical Performance of MOF-Derived NiO-ZnO Oxide Composites for Wastewater Treatment and Sustainable Energy Storage

Abstract

Solar energy is a crucial and sustainable resource, necessitating material optimization for efficient use in solar-driven applications, particularly photocatalysis. Mixed-metallic nanocomposites, notably those derived from metal-organic frameworks (MOFs), have emerged as promising functional materials for environmental remediation and electrochemical energy storage. MOFs provide unique platforms for synthesizing diverse nanostructures, incorporating metals, oxides, sulfides, and nitrides within a porous carbon matrix. These resulting nanocomposites exhibit high crystallinity, retained morphologies, and tunable textural features. This study focuses on synthesizing a MOF-derived Ni/Zn nanocomposite (i.e., MD-Ni/Zn) from a bimetallic MOF to exploit its potential in photocatalytic pollutant degradation and electrochemical energy storage. Under UV irradiation, the MD-Ni/Zn nanocomposite efficiently degrades 98% of mixed ($\text{RhB}+\text{CV}$) dye within 60 minutes. This remarkable photocatalytic performance is attributed to the occurrence of mixed phases in the MD-Ni/Zn nanocomposite, minimizing the recombination efficiency of photoinduced e-/h+ through the p-n heterojunction mechanism. Electrochemical analysis reveals outstanding capacitance in the MD-Ni/Zn nanocomposite, reaching 1002 F/g at 5 A/g, emphasizing its suitability for enhanced electrochemical energy storage.