Plasmon-induced resonant energy transfer and flat band formation in Fe and Co doped Ni( <scp>ii</scp> ) hydroxide for efficient photocatalytic oxygen evolution

Enhancing photocatalytic oxygen evolution is vital for renewable energy. In this work, we demonstrate how plasmon-induced resonant energy transfer (PIRET) from gold nanoparticles (AuNPs) to Fe- and Co-doped nickel hydroxide (Ni(OH)₂) can improve this process. PIRET involves the transfer of energy from excited AuNPs to nearby molecules, boosting their reactivity. We show that doping Ni(OH)₂ with Fe or Fe/Co results in a significant enhancement in photocatalytic activity, achieving a 72% increase in oxygen evolution reaction (OER) performance compared to pristine Ni(OH)₂ layered double hydroxide (LDH). In addition, a reduced optical band gap from 2.8 eV (pristine Ni(OH)₂ LDH) to 2.3 eV and the formation of flat bands was observed, enabling efficient energy transfer upon plasmonic nanoparticle integration and enhancing electronic properties. This supports that the PIRET mechanism is responsible for the increased OER performance. This study demonstrates the crucial role of PIRET in enhancing plasmonic energy transfer and the synergistic effects of doping and AuNP coupling. These findings highlight the broader potential of material engineering in advancing efficient and sustainable energy technologies.