| Diamond is a functional material with unique physical and chemical properties,such as ultra-wide band gap,chemical inertness,ultra-high hardness,and high thermal conductivity.With the development of science and technology,the application environment of materials is becoming more severe.The diamond has broad application prospects and research value.At present,the studies of diamond focus on high quality epitaxial material,a new structural and functional materials,thus the application field of diamond is expended.The micro-nano structure and surface functionalized modification of diamond can produce new characteristics,which significantly improves the performance,and opens up new application fields.The main research contents of this paper are two parts.On one hand,the surface wettability of diamond films under different structures,surface chemical modification and polarity probe liquids was studied and analyzed.On the other hand,diamond films were prepared by chemical vapor deposition(CVD)epitaxial method,and the gold layer was deposited on the surface of the films,and then treated by wet annealing under high temperature water vapor.Diamond electrochemical electrode was prepared by using this structure for the trace detection of clenbuterol hydrochloride(CLB).The main results are as follows:(1)The contact angle and surface energy values of diamond are systemically investigated in terms of surface treatments(hydrogen-and oxygen-terminations),structure feature(single crystal diamonds and polycrystalline diamond films),crystal orientation((100),(111)and mixed(100)/(111)orientations),different fluids(probes of polar deionized water and nonpolar di-iodomethane).It is found that the hydrophobic/hydrophilic characteristic and surface energy values of diamond are mainly determined by the surface hydrogen/oxygen termination,and less related to thestructural features and crystal orientation.Based on the contact angle values with polar water and nonpolar di-iodomethane,the surface energies of diamond are estimated to be about 43 mJ/m~2 for hydrogen-termination and about 60 mJ/m~2 for oxygen-termination.Furthermore,the varying surface roughness of diamond and fluids with different polarities examined determine the variation of contact angles as well as the surface energy values.These results would be helpful for a more detailed understanding of the surface properties of diamond films for further applications in a broad number of fields,such as optical and microwave windows,biosensors,and optoelectronic devices,etc.(2)In this work,an electrochemical electrode material consisting of porous boron-doped diamond(pBDD)films modified with gold Au nanoparticles(Au-NPs),named as Au-pBDD,has been fabricated by a wet annealing process of water vapor on a BDD film surface with a sputtered Au nanolayer.Experimentally,the electrochemical sensor with the Au-pBDD electrode exhibits high sensitivity to clenbuterol(CLB)with a low detection limit of 0.066?M and a wide linear detection range of 0.1?M–100?M.The high performance sensitivity can be attributed to the designed electrode having increased surface area with porous structure and reduced impedance by depositing Au nanoparticle,leading to the effective improvement of the electrochemical activity.The reproducibility,repeatability,stability,and anti-interference for the electrodes,which are required in practical applications,have been examined showing higher performances with respect to the most traditional electrodes for trace CLB detection.In this paper,the wetting property and surface energy of diamond film under different conditions were studied and analyzed,which was more beneficial to the practical application of diamond in various fields.A new Au-pBDD composite structure was prepared by micro and nano processing of BDD thin film,and its main formation mechanism was studied,In the trace detection of CLB of clenbuterol the electrode had good detection level,which expanded the application of diamond sensor in the field of electrochemistry. |
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