The graphene, discovered in 2004, resulted in the beginning of a race for the composition of two-dimensional materials of one layer, with a thickness ranging from one person to a few nanometers. These materials have unique properties that have their dimensions and play an important role in the development and development of nanotechnology and nanomechanics.
An international team of researchers, including Brazilian scientists working with the University of Campinas, created a new material with such features: More specifically, they managed to extract a two-dimensional material, called hematin, from an otherwise conventional iron ore. This material has a thickness of only three atoms and is considered to have improved photocatalytic properties.
The research was presented in Nature Nanotechnology. Douglas Soares Galvao, one of the researchers, said this material can act as a photocatalyst by breaking water into hydrogen and oxygen – something of particular interest, given that hydrogen can produce electricity, among many other possible applications.
This new material comes from hematite, one of the most common minerals on Earth and a basic source of iron. Unlike its carbon and its two-dimensional form, gram-hematite is a non-van der Walls material, which means it is retained by three-dimensional bond networks instead of non-chemical and comparatively weaker van der Waals atomic interactions, sharing one or more pairs of electrons by the individuals participating in the links.
Tests and mathematical calculations made to determine the magnetic properties of the new material have shown that they are less than their hematite counterparts. Also, with regard to its photocatalytic properties (the ability to increase the speed of a chemical reaction when activated by light), photocatalysis by haematine was found to be far more efficient than photocatalysis by hematite. In order for a material to be an effective photocatalyst, it must absorb the visible spectrum of the sunlight, generate electrical charge and transfer it to the surface of the material to effect the desired reaction.
According to the researchers, hematin photocatalysis is more efficient because photons produce both positive and negative charges within a few atoms from the surface. By combining the new material with special titanium dioxide nanotube networks, which provide an easy way to let the electrons out of the blood, scientists have found that more visible light can be absorbed. This paves the way for use in new generation devices that use spintronic (or magneto) technology to store, display, and process information based on changes in rotation of an electron.