Preparation Of Graphdiyne And Its Multifunctional Sensing Properties

Sensors are widely used in military and civilian fields.In the military field,it can be used for guidance,remote sensing monitoring,and imaging.In the civilian field,it can be used for smoke monitoring and alarm,environmental monitoring,health care,and security.In recent years,the emerging two-dimensional allotrope carbon material graphdiyne（GDY） has shown its attractiveness in the fields of information technology,electronics,energy,catalysis,photodetector and sensing due to its special electronic structure and pore structure.Especially GDY has moderate forbidden band width and carrier mobility,showing advantages in the field of optoelectronics compared with traditional two-dimensional materials.At the same time,GDY has large specific surface area and high-activity alkyne bond units providing a good opportunity for the adsorption of gases or water molecules.It also has great application potential in humidity sensing.However,the current use of GDY as the main material for photoelectric sensors and humidity sensors is far from being involved,let alone the use of GDY to construct large-area thin-film prototype devices and flexible devices.Based on this,the following works have been carried out in this article:（1）GDY film is synthesized and its application in photosensor.We used the two-phase interface method to successfully prepare a high crystallinity GDY film.A series of characterization analysis shows that the GDY film have good continuity,uniformity,high crystallinity,thickness of about 64.6 nm,layer spacing of 0.365 nm,and obvious alkyne bonds.By transferring this high-quality GDY film on the surface of SiO₂/Si,a visible light sensor based on GDY film field effect transistor（GTFT）was constructed.The raw GDY film exhibits typical P-type semiconductor electron transport characteristics.At room temperature,the conductivity of is 1.2×10³ S/m,the carrier mobility of is 13.3cm²V^-1s^-1,and the switching ratio of is 10².As the temperature increases,the electrical conductivity also increases significantly.Especially this prototype device demonstrates outstanding response performance to visible light,as well as high stability and repeatability.With the faster response and recovery speed.（2）Preparation of GDY powder and structure humidity sensor.We synthesized GDY on the surface of copper sheet by alkyne-alkyne coupling reaction.Then the GDY powder was dispersed into GDY ink and printed on a PET substrate with interdigitated electrodes to construct a humidity sensor.This sensor shows high sensitivity and good cyclicity under any humidity environment,and the fast response and recovery time can reach 2.2s and 2.1s,respectively.We experimentally measured the contact angle between water molecules and GDY,and found that there is a moderate wetting function between water molecules and GDY,which is helpful for the adsorption and desorption of water molecules on the surface of GDY.In addition,the mechanism of GDY humidity sensing was also qualitatively analyzed.This convenient device construction method and excellent performance open-up new fields of moisture-sensitive sensing materials and expanded new applications for GDY.These studies provided a new strategy for constructing large-area thin-film devices by transfer method,and the printing method for constructing flexible devices is conducive to industrial production.At the same,the constructed prototype photosensor not only has the function of a field effect transistor,but also the function of a photosensor.Moreover,these studies are the first application of GDY as a host material in photosensitive sensors and humidity sensors.It not only experimentally verifies the excellent intrinsic semiconductor properties of GDY,but also open-up a new path for the application of GDY.