Carbon Nitride Layers as Light-Harvesting Semiconductors for Photoelectrochemical Cells

Tue, 19/10/202112:15
Seminar Hall, Los Angeles Building, entrance floor

ProfMenny Shalom. Menny Shalom (BGU)

Chemistry Department, Ben-Gurion University of the Negev, Beer-Sheva, Israel


One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical cells (PECs) – a technology that could potentially convert sunlight and water directly to a clean, environmentally friendly, and cheap hydrogen fuel. Practical PEC-mediated hydrogen production requires robust and highly efficient semiconductors, which should possess good light-harvesting properties, a suitable energy band position, stability in harsh conditions, and a low price. Despite significant progress in this field, new semiconductors that entail such stringent requirements are still sought after.
Over the past few years, graphitic carbon nitride (CN) has attracted widespread attention due to its outstanding electronic properties, which have been exploited in various applications, including photo- and electro-catalysis, heterogeneous catalysis, CO2 reduction, water splitting, light-emitting diodes, and PV cells. CN comprises only carbon and nitrogen, and it can be synthesized by several routes. Its unique and tunable optical, chemical, and catalytic properties, alongside its low price and remarkably high stability to oxidation (up to 500 °C), make it a very attractive material for photoelectrochemical applications. However, only a few reports regarded CN utilization in PECs due to the difficulty in acquiring a homogenous CN layer on a conductive substrate and our lack of basic understanding of the intrinsic layer properties of CN.
In this talk, I will introduce new approaches to grow CN layers with altered properties on conductive substrates for photoelectrochemical application. The growth mechanism and their chemical, photophysical, electronic, and charge transfer properties will be discussed.