Valence Band Cavitation Research of Nano Diamond

Nano diamond is very small crystal material, only the size of nanometer. Although they have the same crystal structure with diamonds, its properties are different compared with common diamond and synthetic diamond. Compared with small volume, the influence of nano diamond surface properties is greater. The suspension nano diamond in aqueous solution can serve as free carrier of active materials in biomedical applications, used as the catalyst for water decomposition.

Recently, the HZB team from the research center of Helmholtz Association of German studies that the electronic properties of nano diamond deposited on the solid substrate is different from that of nano diamond in aqueous solution under the leadership of Dr. Emad F. Aziz. By applying BESSY II absorption and emission spectrum, it can be studied. Their results are published in Nanoscale, which mainly explain the valence band electron cavitation that nano diamond shows in the suspension liquid, but this phenomenon is not found in the film.

"In the water, nano diamond and its neighbours are very strong in the interaction of molecules and ions", Petit says. By adding salt to change the pH value activity, it can change the adsorption of active pharmaceutical ingredient on the nano diamond. Petit and his colleagues find that the surface electronic state of nano diamond in suspension liquid is significantly different from that of nano diamond on solid matrix .

Researchers have tested liquid samples by using X-ray spectra in vacuum conditions, and draw detailed valence band and conduction band electron filling and missing images. The results show that the surface of nano diamond in suspension liquid will form the valence band electrons missing cavitation. This phenomenon shows that the electron on the surface of nano diamond is contributed to the surrounding water molecules. Physicists also begin to suspect that if they change the electronic structure of the nanoparticles, it is possible to influence their chemical, optical, and catalytic properties. In the future, they will further study whether the catalytic effect of nano diamond under the water environment can be enhanced and make water molecules decomposed into oxygen and hydrogen.