Study On The Synthesis And Sensing Application Of Black Phosphorus Based Nanocomposites

Black phosphorus,an emerging two-dimensional(2D)nanomaterial,has attracted tremendous attention since 2014 due to its unique properties.Similar to graphene,bulk black phosphorus is a layered material of individual atomic layers stacked by van der Waals interactions.Different from graphene and other 2D nanomaterials which are atomically flat,BP is formed by puckered double layers.This unique structure endows BP with fascinating electronic properties,such as prominent carrier mobility,tunable thickness-dependent direct bandgap and in-plane anisotropy.BP has been considered as a promising material for many applications such as optoelectronic devices,solar cells,transistors,and sensors.Based on the previous work,the present work carefully studied the synthetic methods for two-dimensional black phosphorus nanosheets.Based on which,Hb/IL/PDDA/BP biosensor and CuNPs/Chit/BP non-enzymatic electrochemical biosensor were developed.The main content includes the following aspects:1.A two-dimensional black phosphorus nanomaterial was prepared by water-phase ultrasonic liquid phase exfoliation method,and the experimental conditions such as ultrasonic time,centrifugation rate and centrifugation time were optimized.The transmission electron microscope(TEM),X-ray photoelectron spectroscopy(XPS)and Raman spectroscopy(Raman)were used to characterize the morphology and structure of the obtained two-dimensional black phosphorus nanosheets.The intrinsic electrochemical behavior of BP in the aqueous phase and the organic phase were also explored.2.A functionalized black phosphorus(BP)nanocomposite was synthesized by non-covalently combining ionic liquid(IL)and poly(diallyldimethylammonium chloride)(PDDA)with BP.The synthesized nanocomposite had good biocompatibility,good solubility and enhanced electrical conductivity,which facilitated the immobilization of hemoglobin(Hb)on the electrode surface and the direct electron transfer(kET=15.36 s-1).The constructed Hb/IL/PDDA/BP biosensor exhibited a good catalytic performance for the reduction of nitrite in the concentration range of 80 ?M to 3.8 mM.3.A copper/chitosan/black phosphorus nanocomposite(CuNPs/Chit/BP)was fabricated by electrochemically depositing copper nanoparticles onto black phosphorus-modified glassy carbon electrodes in chitosan solution.The synthesized nanocomposite had larger specific surface area and higher catalytic activity.Electrochemical methods were used to study the electrochemical performance of CuNPs/Chit/BP nanocomposite on the reduction of hydrogen peroxide.Results showed that the synthesized CuNPs/Chit/BP non-enzymatic sensor exhibited high-efficient electrocatalytic activity toward hydrogen peroxide reduction in the range of 0.1 mM to 6 mM.