Plasmonic Nanocrystal-MOF Nanocomposites as Highly Active Photocatalysts and Highly Sensitive Sensors for CO₂ Reduction over a Wide Range of Solar Wavelengths

Plasmonic nanocrystals have the potential to be widely used in green energy-related applications, due to their excellent optical properties and high reactivity over a wide range of solar wavelengths. Another benefit of using plasmonic nanocrystals for optical applications is that these nanocrystals strongly enhance Raman scattering and are therefore widely used in sensors. Recently, nanocomposites of porous materials deposited on plasmonic nanocrystals are demonstrated to enhance chemical reactivity by concentrating reactants on the surface of plasmonic nanocrystals. Here, three different plasmonic nanocrystals producing plasmonic responses within 400–900 nm are used as templates, and MOF-801 (Zr-based MOF) is produced on these nanocrystals as photocatalysts for the CO₂ reduction reaction. Using nanocomposites as CO₂ reduction reaction photocatalysts, the CO₂ conversion rate can reach >50% within 30 min. The CO₂ reduction reactivity of nanocomposites can be improved by the composition and morphology of plasmonic nanocrystals (increased by 40–50%), due to stronger synergistic effects and higher surface area to volume ratio. This report demonstrates that by controlling the plasmonic responses of nanocrystals, it is possible to realize photocatalysts that can be used for CO₂ reduction reactions over a wide range of solar wavelengths.