Nano Carbon Nitride Photocatalysts With Custom Properties

The industry has an increasingly pressing need to move to new sustainable synthetic schemes to access widely used chemicals. In this context, it is essential to achieve heterogeneous photocatalysis processes with readily available metal-free catalysts.

Carbon nitride is a carbon and nitrogen-based nanomaterial, capable of absorbing visible light and using the energy contained in photons to catalyze chemical reactions of industrial interest. Carbon nitride is an easy photocatalyst to produce on a large scale from inexpensive and widely available precursors. This heterogeneous material is stable, robust and easily recyclable. Additionally, the use of carbon nitride can replace that of expensive and potentially toxic metal-based catalysts.

A study conducted in the CIC biomaGUNE Carbon Bionanotechnology laboratory, published in Science Advances, has determined how simple post-synthetic structural changes can greatly influence the photocatalytic activity of carbon nitrides. "The improvement of the chemical-physical properties of this material can give new structural characteristics to carbon nitride and, therefore, modify its photocatalytic activity", explains Professor Ikerbasque and AXA Chair Maurizio Prato. The novelty of this study lies in "the evaluation of how different post-synthetic modifications confer different and specific photocatalytic activities of the resulting materials in relation to an organic reaction model".

In particular, innovative mechanistic studies have been carried out related to the interaction between the surface of nanomaterials and the reagents used. This interaction varies with post-synthetic modification and, consequently, the most catalytically effective carbon nitride could be selected. Furthermore, "the rationalization of the chemical phenomena that occur on the surface of the material turned out to be a fundamental parameter for the design of new and more efficient catalytic systems", he states.

Currently, the use of carbon nitride for the production of clean energies such as hydrogen production, oxidation of water into oxygen and transformation of carbon dioxide into organic compounds of industrial importance is being studied. "In our study, an organic reaction was developed for the synthesis of molecules with a high fluoride content, useful in the pharmaceutical, agri-food and materials science fields", adds Prato. The reaction studied was also carried out in the presence of sunlight "showing excellent yields".

In Prato's opinion, "our study can be a starting point to establish a new approach in the development of heterogeneous photocatalysts, and lays the foundations for a new approach in the engineering of these materials in relation to specific applications".