LSPR-Driven Heterojunction Catalysts for Enhanced Photothermal CO₂-to-Methanol

The Cu-CeO₂-L catalyst exhibiting localized surface plasmon resonance (LSPR) characteristics was successfully fabricated via a urea-mediated self-assembly strategy. Under reaction conditions of 160 °C and 2 MPa (CO₂/H₂ = 1:3), the catalyst demonstrated a remarkable methanol yield of 2408.34 μmol·g^-1·h^-1, which was 3.48 times higher than the performance without light illumination. Monochromatic light experiments revealed similar performance at 550 and 365 nm, indicating that LSPR-generated "hot electrons" from Cu nanoparticles effectively overcame activation barriers in CO₂ hydrogenation. Structural analyses revealed electron migration from the CeO₂-L support to Cu nanoparticles via oxygen vacancies (O_v), forming a metal-support heterojunction. This interfacial architecture facilitated the creation of a built-in electric field (IEF), significantly accelerating the charge transfer dynamics. Density functional theory (DFT) calculations and in situ DRIFTS results further corroborated that electron-enriched Cu sites promoted H₂ dissociation and the methanol synthesis pathway. The synergy of LSPR effects with the heterojunction provides an innovative method for nanoscale-level modulation of catalytic active sites, advancing the design of plasmon-enhanced photocatalysts for CO₂ conversion.