In the project "Controlled Growth of Lightweight Metal-Free Materials for Photoelectrochemical Cells" we address one of the main challenges of developing sustainable energy production.
To this end, we aim to develop different metal-free materials, focusing on the family of carbon-nitride-based polymers with different heteroatoms to be used as the photoactive ingredient in photoelectrochemical cells (PEC).
These cells absorb solar light, thus reducing the required energetic input for performing liquid-phase reactions for the production of fuels. The most common PEC is the water-splitting cell, where electrons reduce water to hydrogen (the clean fuel) on the cathode, while on the other side (the photoanode), water is oxidized to oxygen.
This is a very promising concept, yet despite decades of research for real-world application, significant scientific challenges have yet to be met.
At the core of this MFREEPEC project is the development of photoactive materials. We introduce a new class of metal-free materials that are particularly suitable as semiconductors in PECs through the development of new strategies for the controlled synthesis and growth of metal-free materials on various substrates, ranging from carbon nitride to nitrogen-doped carbon and new carbon-nitrogen-phosphorus/boron/sulfur materials (referred here as CNXs, X = P, B or S).
We aim to overcome the current limitations of the traditional synthetic and growth methods for CNXs layers with controlled properties by designing and encoding the elemental composition of the final material at the molecular level. By rationally selecting the reaction monomers, we will target specific properties required for PECs: suitable optical band gap, crystal structure, porosity, layer thickness, and catalytic activity, as well as the design of a beneficial electronic structure for efficient charge separation and collection.
The overall objective is to assemble working PEC systems where the designed photoactive layer surpasses the state-of-the-art performance and allows long-term stability, which is crucial for future commercialization.
Specifically, we improve the properties of the photoactive material(s) (light absorption, charge transport characteristics, and so forth) and the PEC configuration (which layers are used, deposition of transporting/blocking layers, co-catalysts integration, interface engineering, functionalization, etc.).
This research is vital for society as it is essential to provide an alternative way of production of clean fuels (mainly hydrogen) and, if possible, achieve valuable chemical transformations as side reactions (for example, replacing oxygen evolution with other helpful products).
