Preparation Of Copper-Based Nanomaterials And Their Photocatalytic And Electrocatalytic Performances In C-C Coupling Reaction

Carbon-carbon（C-C）coupling reactions are one of the most powerful tools for the synthesis of biologically active complex natural products and the development of pharmaceuticals and agrochemicals.Copper-based nanomaterials are widely used in photocatalytic C-C coupling reactions due to their excellent photothermal catalytic performance,which also extensive used in carbon dioxide electrochemical reduction reaction.In this work,a multifunctional composite for C-C coupling reaction was successfully fabricated via encapsulating the core-shell Cu@Ni nanocubes into ZIF-8（Cu@Ni@ZIF-8）.In this nanoreactor,Ni shell of the core-shell Cu@Ni nanocubes was the catalytical active center,and Cu core was in situ heating source for the catalyst by absorbing the visible light.Moreover,benefits from the plasmonic resonance effect between Cu@Ni nanocubes encapsulated in ZIF-8,the absorption range of composite was widened and the utilization rate of visible light was enhanced.Most importantly,the microporous structure of ZIF-8 provided shape-selective of reactant.The results showed that the product yield of Cu@Ni@ZIF-8 composites catalyzed the C-C coupling reaction of 2-furanboronic acid was 62%under the condition of room temperature and xenon lamp irradiation,which was higher than that obtained under non-xenon lamp irradiation and heated to 60℃in an oil bath（60%）.After five cycles,the yield dropped by only 6%.This Cu@Ni@ZIF-8 composite opens a way for photocatalytic C-C coupling reactions with shape-selectivity.Ultrathin Cu₂O nanosheets with a thickness of 0.9 nm were synthesized by aqueous reduction of Cu（OH）₄^2-precursor and applied in carbon dioxide electrochemical reduction reaction.The FE of ultrathin Cu₂O nanosheets for electrochemical reduction of carbon dioxide to the C₂+product reaches a maximum of 75.25%at an applied potential of-1.2V（vs.RHE）.The FE of C₂+products can be maintained above 74%,and the FE of hydrogen evolution reaction can be suppressed below 12%in the range of-1.2 V（vs.RHE）to-1.4 V（vs.RHE）.The ultrathin Cu₂O nanosheets not only exhibit higher C₂+product selectivity over a wide range of applied potentials,but also could well suppress the hydrogen evolution reaction.It is worth noting that the surface roughness of ultrathin Cu₂O nanosheets is much higher than that of Cu O nanosheets.We speculate that the rougher surface of ultrathin Cu₂O nanosheets will generate more highly coordinatively unsaturated active sites during carbon dioxide electrochemical reduction reaction.These active sites will promote the generation of*OCCOH intermediates,which in turn facilitates the selective generation of high value-added multi-carbon products.