Surface Engineered Bimetallic Fe,Ni-MOF Based Nanohybrid for Photocatalytic Green H2 and Natural Benzaldehyde Production

Abstract

Heavy consumption of energy devoted to reliance on fossil fuel sources, which resulted in a detrimental impact on the environment and health. These challenges can be effectively addressed through a sustainable-driven approach that prioritizes the utilization of visible light as a renewable energy source with green chemistry protocols for the production of H2 and value-added chemicals. MOF-based semiconductors are versatile photocatalysts with tunable band structure, abundant active sites, impressive optoelectronic features, enabling efficient solar energy utilization for energy generation and environmental remediation. Herein, bimetallic MIL-88B(Fe,Ni) and Cu2MoS4-based nanohybrid is fabricated for the photocatalytic green H2 generation and natural benzaldehyde production. The substitution of Ni2+ ion in the Fe3O cluster of Fe-MOF creates Fe3+/Fe2+-Ni2+/Ni3+ redox active pair for the stimulated charge migration. The change in the oxidation state coordination environment in bimetallic MIL-88B(Fe,Ni) MOF is investigated by XPS, XANES, EXAFS and ESR studies. Furthermore, the surface modification of Cu2MoS4 by acid etching results in the generation of abundant active sites and Cu-vacancy. The heterostructure shows improved physicochemical and optoelectronic properties compared to the pristine components, which boost photocatalytic efficiency. The comprehensive investigation of photo-induced charge migration in the heterostructure by using Kelvin probe microscopy, femtosecond transient absorption spectroscopy and in situ irradiated XPS reveals S-scheme charge migration. This study illustrates the impact of the bimetallic redox-active center in MOF and surface texture modification of metal sulfide for production of green H2 and benzaldehyde as fine chemical.