Controllable Synthesis And Applications Of Perovskite And Metal Nanomaterials

Functional nanomaterials have attracted wide attention in various fields,such as chemistry,physics,materials and energy related.How to achieve effective design,controllable preparation and successful application of functional nanomaterials has been a hot and difficult issue.Metal and semiconductor nanomaterials are important inorganic functional nanomaterials and are the focus of this paper.As a new type of optoelectronic material,all-inorganic metal halide perovskite CsPbX3(X=Cl,Br,I)nanocrystals have excellent optical properties and have been used in diverse fields,such as light-emitting diodes(LEDs),lasers,photodetectors and solar cells.Many methods have been developed to synthesize high quality CsPbX3 nanocrystals,including hot-injection method,solvothermal method and ultrasonic method.These methods have several advangtages,such as simple operation,good reproducibility,uniform size and high yield.However,they have been limited by the poor morphology control and high energy consumption.In order to solve the above problems,this paper successfully prepared CsPbX3 nanocrystals by a microwave-assisted method from the methodological point of view.This method has the advantages of low energy consumption,high speed,high yield and controllable morphology.The obtained nanocrystals are applied to LEDs and exhibit excellent performance.Metal nanomaterials have been widely used as catalyst.It has been reported that their physicochemical properties and catalytic properties are highly dependent on their morphology and size.To date,the research on metal nanocatalysts has made important progress.However,there are still many challenges,especially the difficultyin size control and unclear catalytic mechanism.In this paper,we use the combination of theoretical calculation and experimental verification to reveal the difference in activity of different Pd nanocrystals in the hydrogenation reaction of alkyne,and then reveal the catalytic sites in the progress of the reaction,and clarify the catalytic mechanism.In addition,we have prepared a new semiconductor material(Ga2O3),which successfully changed the active sites of Pd nanocrystals and explored the strong metal-support interaction(SMSI)between Pd and Ga2O3.Herein,the main work of this paper is as follows:1.A novel method(microwave-assisted heating)has been developed to synthesize high-quality halide lead perovskite NCs with controlled size and morphology.A plausible growth mechanism has been proposed,in which the morphology was changed from nanosheets to nanocubes.The as-synthesized nanocrystals have been successfully used as the photoluminescent material in a LED prototype device.2.Pd nanocrystals with different morphologies can be prepared.We combined theoretical simulation calculations with experimental data and revealed the active sites of Pd nanocrystals in the propyne hydrogenation.We found that Pd octahedron has higher propylene selectivity than that of Pd cube.And the main active site of hydrogenation occurs at the top of the Pd octahedron,instead of the edges or surface.3.Pd-Ga2O3 nanoparticles with very uniform morphology have been designed and prepared.We explored the SMSI between Pd and Ga2O3.The as-prepared Pd-Ga2O3 composite nanoparticles can be directly used for propyne hydrogenation.The catalyst in the process exhibits excellent activity and selectivity.