Artificial Photosynthesis using graphite Carbon Nitride

Fine chemicals and hydrogen production from water, carbon dioxide, and solar energy are ideal future chemical and energy sources independent of fossil reserves. The development of new functional molecular materials (catalyst) for the application in fine chemical and clean energy production using water and solar energy is fascinating and quite challenging because the catalyst must be sufficiently efficient, stable, inexpensive, and capable of harvesting light. 

Polymeric graphite carbon nitride (C₃N₄) materials are commonly available simple semiconductor photocatalysts. It is being non-volatile up to 600⁰C even in the air with no detectable solubility or reactivity in conventional solvents, including water, alcohols, DMF, THF, diethyl ether, and toluene. Carbon nitride is considered to be extremely stable and basic in nature. It can be used as the multifunctional heterogeneous catalyst for fine chemical and pharmaceutical synthesis as well as a good organic semiconductor due to its right bandgap (2.7 eV corresponding to an optical wavelength of 460 nm). 

Prof. Markus Antonietti and his team at Max Planck Institute of Colloids and Interfaces in Germany, have successfully split CO2 or photochemically turn water into hydrogen and oxygen using graphite carbon nitride. However, only four micromoles of hydrogen per hour were produced out of the researcher's reaction vessel (quantum efficiency of the Pt modified CN is approximately 0.1% with irradiation of 420-460 nm). This opens the door to artificial photosynthesis and produces chemicals and energy from greenhouse gas /solar energy. It will contribute to the prevention of global climate change.