Preparation Of Black Phosphorus Catalyst And Study On Photocatalytic Performance Of Black Phosphorus

Black phosphorus is a new type of two-dimensional material with good application potential in the fields of energy storage,photocatalysis,electronic devices,and biomedicine.The reported preparation process of black phosphorus cannot meet the needs of mass production,which limits the basic and applied research of black phosphorus.The preparation method of black phosphorus based on the phosphorus-iodine ternary complex(Sn₂4P_19.3I₈)catalyzed by the steam conversion of red phosphorus is the most likely to be industrialized at present,but the existing Sn₂4P_19.3I₈ catalyst is a non-porous powdery solid.It is difficult to meet the catalytic activity,mechanical strength and specific surface area required by industrial equipment.On the other hand,the crystalline phosphorous elemental material has good visible light absorption ability and suitable band gap structure,making it a good candidate for photocatalytic water splitting.Based on this background,this thesis improves the catalytic performance of Sn₂4P_19.3I₈ by studying the forming method of Sn₂4P_19.3I₈,and improves the photocatalytic hydrogen evolution performance of the composite material by constructing a black phosphorus/crystalline red phosphorus heterostructure.The specific research content is as follows:（1）It is found that the introduction of tin diiodide as a promoter during the black phosphorus preparation can promote the formation of black phosphorus unit cells and further accelerate the growth of black phosphorus crystals.After the introduction of tin diiodide,the average black phosphorus yield increased from 83%to 87%,and the product was pure orthorhombic black phosphorus crystals.（2）Preparation of three shaped catalysts,namely Sn24P19.318/SiO2 catalyst,Sn₂4P_19.3I₈ self-forming catalyst and Sn₂4P_19.3I₈/Crd（cordierite）catalyst,all exhibiting higher catalytic activity than Sn₂4P_19.3I₈ powder,Sn₂4P_19.3I₈/Crd（cordierite）catalyst has the highest mechanical strength and catalytic activity.（3）A set of micro-reactors that simulate industrial production were designed and manufactured,and the catalytic activity of the Sn₂4P_19.3I₈/Crd（cordierite）molding catalyst was further evaluated,which increased the black phosphorus yield to 93%.（4）Using the prepared black phosphorus as the raw material,the black phosphorus is obtained by electrochemical exfoliation.The black phosphorus nanosheet is combined with the crystalline red phosphorus nanobelt to form a new type of heterostructure photocatalyst,which can be used without sacrificial agent.The photocatalytic hydrogen evolution rate is 579μmol h^-1g^-1.The involved photocatalytic mechanism is also proposed.