Synthesis And Photocatalytic Properties Of Cu₂O@MOF Nanosheets Composites

In recent years,the rapid development of industry and the rapid growth of the global population have caused serious energy shortages and environmental pollution problems.There is therefore an urgent need to develop environmentally friendly and renewable technologies for environmental management and green energy production.Among the various technologies that have been developed,semiconductor photocatalysts have great potential for the direct use of solar energy in the production of high value-added chemical fuels,such as hydrocarbon fuels and hydrogen.In this field,copper oxide（Cu₂O）photocatalysts contribute to the efficient absorption of visible light due to a suitable band gap structure（2.0-2.2 e V）.However the photocatalytic activity of Cu₂O is still limited by the high recombination rate of photoexcited electron-hole pairs and photostability issues.Ultra-thin two-dimensional metal-organic frameworks（2D MOFs）materials have the advantages of both 2D materials and MOFs,and they are increasingly used for applications in photo/electrochemistry and energy storage.The preparation of composite materials with dense contact surfaces by combining Cu₂O with ultra-thin 2D MOFs is one of the effective ways to solve the current problems faced by Cu₂O and substantially improve the photocatalytic activity.Based on this,we are committed to exploring suitable methods to prepare Cu₂O-based composites to enhance Cu₂O photocatalytic activity.The specific research in this paper is as follows:1.Cu₂O@Cu-TCPP composites were successfully synthesized using Cu₂O as a sacrificial template.A series of Cu₂O@Cu-TCPP composites Cu₂O@Cu-TCPP-1,Cu₂O@Cu-TCPP-3 and Cu₂O@Cu-TCPP-6 were synthesized by controlling the material ratios.It was shown that the amount of Cu₂O and TCPP greatly affects the morphology of the composites and catalytic properties.Experimental results indicate that the Cu₂O self-sacrificing template method is an effective strategy for the preparation of Cu₂O@Cu-MOF composites.The presence of MOF successfully solves the defects of Cu₂O,and the tight interface between Cu₂O and MOF through ligand bonding links facilitates the charge transport.As a result,the material exhibits excellent charge separation efficiency and good photochemical stability.The results of the photocatalytic CO₂ reduction also show that the HCOOH yields of the Cu₂O@Cu-TCPP composites are all much higher than those of Cu₂O,up to 3974μmol/g.2.Using the self-sacrificial template method of Cu₂O,Cu-BDC nanosheets with ultra-fine Cu₂O（1.7 nm）nanoclusters（U-Cu₂O@Cu-BDC）were successfully synthesized at the double-solvent interface.The results of photocatalytic experiments showed that the catalyst exhibited the well catalytic activity up to 4860μmol/g.And we further introduced different transition-metal ions to explore the synergistic effect.