Balancing Plasmonic Response and CO2 Activation in Au–Cu/TiO2 Hybrid Photocatalysts via Alloy Composition Control
Abstract
Plasmonic metal–semiconductor hybrid catalysts offer a versatile platform for solar-driven CO2 photoreduction by integrating efficient light harvesting with catalytic activation. Here, Au–Cu/TiO2 hybrid photocatalysts are developed as a model system to elucidate the role of plasmonic excitation and surface chemistry in governing CO2 reduction activity and selectivity. Alloyed Au–Cu nanorods with controlled Cu incorporation were synthesized and assembled with TiO2 nanoparticles, enabling systematic modulation of the Au/Cu ratio while maintaining constant metal and semiconductor loadings. The resulting Au–Cu/TiO2 interface functions as a tandem photocatalytic system, where Au promotes hot-carrier generation, TiO2 facilitates charge separation, and Cu enhances CO2 adsorption and stabilization of reaction intermediates. Under broadband illumination (350–2400 nm), pristine TiO2 shows limited activity, whereas Au incorporation enables the formation of formic acid, methane, and ethanol. Increasing Cu content significantly improves CO2 conversion while modulating product distribution: low Cu concentrations favor ethanol production, whereas higher Cu loading promotes formic acid and methane formation with enhanced hydrogen evolution. These findings establish composition-dependent structure–property–function relationships in Au–Cu plasmonic photocatalysts and provide design principles for controlling activity and selectivity in solar-driven CO2 conversion.
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BibTeX
@misc{sousacastillo2026balancing,
title = {{Balancing Plasmonic Response and CO2 Activation in Au–Cu/TiO2 Hybrid Photocatalysts via Alloy Composition Control}},
author = {Ana Sousa-Castillo and Alexey V Krasavin and Diptiranjan Paital and Shannon Stockdale and David R Richards and Anatoly V Zayats and Yoel Negrín-Montecelo},
howpublished = {ChemRxiv},
year = {2026},
month = oct,
doi = {10.26434/chemrxiv.15010449/v1},
url = {https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010449/v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - Balancing Plasmonic Response and CO2 Activation in Au–Cu/TiO2 Hybrid Photocatalysts via Alloy Composition Control
AU - Ana Sousa-Castillo
AU - Alexey V Krasavin
AU - Diptiranjan Paital
AU - Shannon Stockdale
AU - David R Richards
AU - Anatoly V Zayats
AU - Yoel Negrín-Montecelo
PY - 2026
DA - 2026/10/14
PB - ChemRxiv
DO - 10.26434/chemrxiv.15010449/v1
UR - https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010449/v1
AB - Plasmonic metal–semiconductor hybrid catalysts offer a versatile platform for solar-driven CO2 photoreduction by integrating efficient light harvesting with catalytic activation. Here, Au–Cu/TiO2 hybrid photocatalysts are developed as a model system to elucidate the role of plasmonic excitation and surface chemistry in governing CO2 reduction activity and selectivity. Alloyed Au–Cu nanorods with controlled Cu incorporation were synthesized and assembled with TiO2 nanoparticles, enabling systematic modulation of the Au/Cu ratio while maintaining constant metal and semiconductor loadings. The resulting Au–Cu/TiO2 interface functions as a tandem photocatalytic system, where Au promotes hot-carrier generation, TiO2 facilitates charge separation, and Cu enhances CO2 adsorption and stabilization of reaction intermediates. Under broadband illumination (350–2400 nm), pristine TiO2 shows limited activity, whereas Au incorporation enables the formation of formic acid, methane, and ethanol. Increasing Cu content significantly improves CO2 conversion while modulating product distribution: low Cu concentrations favor ethanol production, whereas higher Cu loading promotes formic acid and methane formation with enhanced hydrogen evolution. These findings establish composition-dependent structure–property–function relationships in Au–Cu plasmonic photocatalysts and provide design principles for controlling activity and selectivity in solar-driven CO2 conversion.
ER -