Construction Of Plasma-Ordered Copper-Based Catalysts And Performance In Photocatalytic Reduction Of CO₂

Plasmonic metals can produce a series of unique effects due to localized surface plasmon resonance（LSPR）,including enhancement of electromagnetic fields,generation of high concentrations of hot carriers,and photothermal effects.Therefore,it has great potential for light-driven chemical transformation.Cu-based plasmonic catalysts have become popular research targets for plasmonic-assisted photocatalysis due to their strong LSPR effect in the visible light range and intrinsic catalytic activity for various reactions.Various Cu-based hybrids have been previously reported to improve the catalytic performance of Cu-based catalysts.However,from the current research perspective,the application of Cu-based photocatalysts is still at an early stage compared to noble metals.In this paper,based on cheap Cu,based on the strategy of plasmonic coupling effect and synergistic advantages of bimetals,the introduction of different metal atoms to enhance the photocatalytic performance of Cu is explored.And successfully constructed a Cu@Co plasmonic bimetallic catalyst with a core-shell structure and a CuAg_x bimetallic aerogel with a three-dimensional porous interconnected structure,realizing the photocatalytic reduction of CO₂ with high efficiency and selectivity.Works as follows:（1）Bimetallic catalysts such as CuRu,CuNi,CuPt,CoCu,CuAu,and CuPd were synthesized by a simple hydrothermal reduction method,and the crystal structure and crystallinity of the obtained catalysts were verified by XRD.The CoCu plasmonic bimetallic catalyst with the best photocatalytic performance was screened out by photocatalytic activity test experiments.（2）Using ethylenediamine as a structure inducer,the metal Co with excellent catalytic activity was positioned on the surface of Cu,and a Cu@Co plasmonic bimetallic catalyst with a core-shell structure was designed and synthesized.The plasmonic metal Cu acts as an"antenna"to generate a large number of carriers to flow to the Co layer under photoexcitation,and Co acts as a"reactor"for photocatalytic reactions on the surface.At the same time,the introduction of the Co layer can improve the absorbance of the sample and the adsorption capacity of CO₂,thereby promoting the activation of CO₂ on the catalyst surface.The plasmonic coupling effect between Co and Cu can also accelerate the transfer and separation of surface carriers.Therefore,the Cu@Co sample exhibits excellent photocatalytic activity and selectivity,with a CO generation rate of 11043.33μmol·g^-1 and a CO product selectivity of 98%without photosensitizers and cocatalysts.（3）Using NaBH₄ as a reducing agent and EtOH as a gel inducer,CuAg_x bimetallic aerogels with three-dimensional porous interconnected structures were successfully synthesized.The unique porous structure brings a larger specific surface area,stronger CO₂ adsorption capacity,and faster carrier separation and transport rate.Therefore,the photocatalytic activity of the metal aerogel structure is much better than that of metal nanoparticles.Both the CO and H₂ yields are greatly improved due to the non-competitive active sites of Cu and Ag.And the ratio of CO and H₂ production can be controlled by adjusting the molar content ratio of Cu and Ag.