Photoelectrochemical Performances Of Black Phosphorous/Black Phosphorous-like Two-dimensional Atomic Crystal Materials

Low dimensional nanomaterials research is a new trend in the field of materials science.In recent decades,new members in the large family of two-dimensional materials constantly appeared.Due to the different structures and characteristics,two-dimensional materials can display their own advantages in different fields.Recent researches focused on the black phosphorus material with excellent photoelectrochemical characteristics which are comparable to that of graphene.In addition,a series of black phosphorus-like materials with the same atomic structure as black phosphorus attract worldwide attention,and most of them show the appropriate band gap and high mobility.The combination of black phosphorus and black phosphorus-like materials as a hybrid dimensional heterostructure can help to achieve synergy effect because of the complementary advantages of each dimension structure,which will open a new gate for the study of high performance photoelectrochemical materials.The photochemical properties of black phosphorus/black phosphorus-like two dimensional atomic crystals were studied on the basis of large-scale production of low dimensional materials,while the ability in the application of electrocatalysis and photoelectric detection devices has also been explored.The following works are:1.The oxygen evolution reaction is a very important half reaction in the energy conversion field.The kinetic process of the reaction often restricts the whole energy conversion and the final efficiency and production during hydrolysis process.In this work,we tested the oxygen evolution reaction activity and structural stability of few-layer two dimensional black phosphorus nanosheets.The results show that the catalytic ability of black phosphorus is much higher than that of its bulk counterpart,the starting voltage of oxygen production is 1.45 V and the Tafel slope is 88 mV dec^-1.Besides that,we also studied the electrocatalytic properties of black phosphorus nanosheets at different electrolyte concentrations and centrifugal speeds.It is proved that the reduction of the thickness of black phosphorus nanosheets can expose additional active sites and increase reactive area for catalytic reaction,which plays an important role to improve the electrochemical performance of material.2.In this part,we utilized KOH as electrolyte for self-power photodetector.In detail,the performance and stability of black phosphorus nanosheets prepared by liquid-phase exfoliation were tested.It is found that the photocurrent of the black phosphorus nanosheets in KOH electrolyte reaches 265 nA cm^-2,and the photocurrent after a week can retain to be 103 nA cm^-2.The results show excellent photodetect ability and good stability of few-layer black phosphorus nanosheets in KOH electrolyte.In addition,the photodetect performance of black phosphorus nanosheets can be further enhanced by adjusting the concentration of KOH electrolyte and bias potential,in addition,the relationship between the photodetect performance and electrolyte concentration has been revealed.3.The preparation routes of two dimensional black phosphorus-like materials?MOS₂,SnSe,WS₂?have been investigated,and the photochemical properties of its hybrid dimensional heterostructure?MX₂-TiO₂?prepared by hydrothermal method were studied.Experimental results show that black phosphorus-like layered material inherits advantages from black phosphorus structure,and at the same time,it has good stability.The overall photoelectrochemical properties of materials were greatly improved compared to single materials when TiO₂ nanoparticles grown on MoS₂ nanosheets.