The joint efforts of researchers from TPU, Germany and the United States have discovered a new way to functionalize a dielectric, otherwise known as "white graphene," hexagonal boron nitride (hBN), without destroying it or changing its properties. Courtesy of the new technique, the researchers synthesized a 'polymer nano carpet' with strong covalent bond on the samples.
The explanation of Prof. Raul Rodriguez from the TPU Research School of Chemistry and Applied Biomedical Sciences is that for the first time, they have managed to covalently functionalize hexagonal boron nitride without intense chemical compositions and the introduction of new defects into the material. The result of the earlier approaches has been in a different material with altered properties, that is, hydrolyzed boron nitride. Now, they utilized nano defects existing in the material without increasing their number, and eco-friendly photopolymerization.
The researchers said that one of the promising options for using the new material is catalysts for splitting water in hydrogen and oxygen. With this approach, 'polymer carpets' functioned as carriers of active substances, that is, matrices. They integrated nickel nanoparticles into the matrix. Then, they used the catalyst obtained for electrocatalysis. The research revealed that they could be successfully used as an alternative to expensive platinum or gold.
The process of forcing the starting material to reach active centers of the catalyst is one of the essential challenges in catalysis. 'Polymer carpets' form a 3D structure that helps to increase the area of contact of the active centers of the catalyst with water and makes hydrogen acquisition more efficient. It is very promising for the production of environmentally friendly hydrogen fuel.
A binary compound of boron and nitrogen is boron nitride. Hexagonal boron nitride or 'white graphene' is a white talc-like powder with hexagonal, grapheme-like lattice. Though it is resistant to high temperatures and chemical substances, nontoxic, it has a very low coefficient of friction and functions both as a perfect dielectric and as an excellent heat conductor. Boron-nitride materials are widely used in the reactions of manufacturing organic synthesis. In the cracking of oil, for the manufacturing of products of high-temperature technology, the production of semiconductors means for extinguishing fires and so on.
There was previous devotion of studies on the functionalization of hexagonal boron nitride. This process typically uses strong chemical oxidants that not only destroy the material but also significantly change its properties. The method, which TPU scientists and their foreign colleagues use, allows them to avoid this.
Prof Raul Rodriguez concluded that studies have shown that they obtained homogenous durable 'polymer carpets' which can be removed from the supporting substrate and used separately. Furthermore, this study is a universal technology since they used different monomers for functionalization which allow obtaining materials with properties optimal for use in various devices.
