Improved Properties of Hexagonal Boron Nitrides Synthesized on a Cupper Foil
OKYAY T. 1, YILMAZ H. 1, CULHA M. 2
1 Sabanci University, ?stanbul, Turkey; 2 Augusta University, Augusta , United States
Two-dimensional (2D) nanomaterials are widely used in diverse applications including bio/chemo sensors, photo electrochemistry, tissue engineering, pharmaceutical and biomedical with their unique structures and extraordinary physicochemical properties. Hexagonal boron nitrides (h-BNs) are one of the 2D materials, similar to graphene, having a honeycomb structure arranged by B and N atoms . hBNs are a wide-bandgap van der Waals crystals with a unique combination of properties, including exceptional strength, large oxidation resistance at high temperatures, and optical functionalities. Conventionally, h-BNs are synthesized using boric acid as precursor under ammonia gas atmosphere at relatively high temperatures, above 1000°C with chemical vapor deposition (CVD) method. However, ammonia (NH3) is extremely hazardous to human health, and its control and monitoring is difficult . The fabrication of h-BNs at a low cost is also another concern which requires reducing the reaction temperature.
In the study, a new procedure was developed for the low cost and highquality h-BNs. In this procedure, a boron and nitrogen precursor, ammoniumpentaborate spread on cupper foil, where the cupper foil served as catalyst, and the temperature is kept at 900°C, below melting point of copper metal foil under nitrogen (N2) gas atmosphere. The obtained h-BNs were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), Infrared (IR) and Raman spectrophotometer for structural, morphological analyses, and electrostatic force microscopy (EFM) for their piezoelectricity. The evaluation of the data revealed that the hBNs synthesized with this new method much better physicochemical and piezoelectric properties compare to other synthesis approaches.
The authors acknowledge the financial support from The Scientific and Technological Research Council of Turkiye (TUBITAK) 1003 research program (Project no: 118F473).