DOI: https://doi.org/10.29363/nanoge.interect.2021.008
Publication date: 10th November 2021
Photoelectrochemical cells (PECs) have been developed as environmentally friendly systems that can directly utilize photogenerated electron-hole pairs for water splitting, fuel production, conversion of carbon dioxide, and pollutant degradation. Most reports on the photocatalytic or PEC hydrogen (H2) evolution via water splitting have focused on the H2 reduction half-reaction by generating on the photoanode a non-valuable oxygen or using sacrificial agents to consume the generated h+, resulting in a a significant waste of energy. Lately, much effort is invested into the synthesis of valuable chemicals on the photoanode while retaining the production of H2 on the cathode.
Over the past few years, polymeric carbon nitrides (CN) attract widespread attention due to their 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 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.
This talk will introduce new approaches to grow CN layers with altered properties on conductive substrates for photoelectrochemical applications. The growth mechanism and their chemical, photophysical, electronic, and charge transfer properties will be discussed. I will show the utilization of PEC with a CN-based photoanode as a stable and efficient platform for the oxidation of organic molecules to added-value chemicals, with hydrogen co-production. The second part of the talk will be focused on the electrocatalytic oxidative upgrading of organic molecules by NiFe-oxide into valuable chemicals.
This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No. [849068])