CARBON NITRIDE AND OTHER C/N- MATERIALS FOR ARTIFICIAL PHOTOSYNTHESIS, AS ELECTROCATALYSTS, AND FOR ENERGY APPLICATIONS

Some recent observations made polymeric graphitic Carbon Nitride a valuable extension to current semiconducting organic materials. This is due to the ease of synthesis, but also due to its extreme chemical stability. Made from urea as reported already by Justus Liebig in 1832, it just recently turned out to be a novel catalyst which- among other reactions- can even chemically activate CO2 or photochemically turn water into hydrogen and oxygen. This opens the door to artificial photosynthesis on the base of a sustainable and most abundant substrate base. Diverse strategies of nanosynthesis and the control of morphological features on that length-scale to improve the performance are presented.

I will present first schemes on chemical reactions where the electronic properties of C3N4 are generalized to other reactions, with C/N-nanostructures successfully mimicking oxidation enzymes with high conversions and selectivity or entering HER and ORR electrodes. Copolymerization is here used to adjust electronic properties and coupled reactivity. Hybridization of carbon nitride with carbon sheets and graphene for instance gives a layered nanocomposite with highly improved catalytic activity,

I will also talk about a potential extension of the carbon nitride family to other C/N-heterostructures, among them “noble carbons” and narrow band semiconductors, and I will show how such structures can be useful as battery electrodes, based on their extreme stability and the ability to address chemical conversion reactions at their surface.

In all cases, the structures can be made on the base of easily available monomers and using simple high temperature conversion schemes towards the final materials.