Solar-Driven Photocatalytic N2 Reduction to Ammonia Using Plasmonic Au@NiZIF-8 MOF Hybrids

Identifier:  imarina:9469029

Handle: https://hdl.handle.net/20.500.11797/imarina9469029

Authors:  Arjones-Fernández, B; Malik, A; Guillade, L; Khatua, R; Besteiro, LV; Sousa-Castillo, A; Vázquez-González, M; Alvarez-Puebla, RA; Correa-Duarte, MA

Abstract:
Photocatalytic ammonia synthesis has emerged as a sustainable alternative to the fossil-fuel-dependent industrial Haber-Bosch process, utilizing solar energy to convert atmospheric nitrogen and water into NH3 under mild conditions. While this method significantly reduces CO2 emissions, it faces challenges such as low nitrogen solubility in water and competition with the hydrogen evolution reaction, which hinder its efficiency and scalability. Here, a core-shell approach is employed to incorporate controlled-morphology plasmonic gold nanoparticles (AuNPs) into Ni-doped ZIF-8 metal-organic frameworks (MOFS), forming a hybrid photocatalyst. In this design, AuNPs serve as the core, while the NiZIF-8 shell prevents nanoparticle agglomeration and facilitates enhanced nitrogen and proton transport to the AuNP surface during illumination. The Au@NiZIF-8 photocatalyst outperforms NiZIF-8 alone, benefiting from improved electron transfer, energy migration, and localized field polarization. These synergistic effects enhance nitrogen activation and stabilize reaction intermediates, significantly improving catalytic efficiency and selectivity. Furthermore, the catalytic activity remains stable across three consecutive cycles.