Controlled Growth of Lightweight Metal-Free Materials for Photoelectrochemical Cells

ended

One of the most promising future sources of alternative energy involves photoelectrochemical cells (PECs) that can convert sunlight and water directly to clean hydrogen fuel. Up to now, the PEC field has been dominated mostly by metal-based materials and despite the progress in this field, semiconductors that fulfil all the stringent requirements as PEC semiconductors do not exist today and novel materials are still much sought after. Thus, the development of suitable semiconductor materials will be a game changer, allowing PECs to fulfil their role in the energy-devices landscape. The aim of this project is to 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 as CNXs, X = P, B or S). Central to this goal is the understanding of the growth mechanism of CNX layers from the molecular level, which will in turn permit the rational design of synthesis and deposition methods. More specifically, we will (i) develop effective deposition pathways of CNXs on substrates with controlled properties, (ii) understand the factors that determine the CNX layer properties and, from this, (iii) control CNXs properties such as band gap, exciton lifetime, crystallinity, porosity, and electronic structure, with the aim of improving their photoelectrochemical activity through rational design of the synthetic parameters. This highly interdisciplinary proposal combines materials science, photoelectrochemistry and supramolecular chemistry. It will open up new opportunities in these fields, in particular in the synthesis and deposition of metal-free materials, and it will significantly accelerate the integration of lightweight materials into energy–conversion and other devices.