Thursday 08 Sep 2016: NEST Seminar: 2D Nanosheets as photocatalysts for water oxidation
Prof. Cecilia Mattevi - Imperial College London
HAR/170 (3D Visualisation Suite) 12:30-13:30
Efficient photoanodes for solar-assisted water splitting are essential to effectively lead to the implementation of solar energy conversion systems. In this talk, I will present our work on photoanodes for water oxidation based on atomically thin layer of transition metal dichalcogenides (TMDCs). Thin films of solution-processed MoS2 and WS2 nanosheets display positive photocurrents and O2 evolution under simulated solar irradiation. WS2 results to be more efficient than MoS2 and further, if MoS2 and WS2 nanosheets are blended to form a bulk heterojunction, the incident-photon-to-current-efficiency increases of one order of magnitude compared to the individual constituents. This proves that charge carrier lifetime can be opportunely tailored in atomically thin crystals by creating heterojunctions of different architectures. Our results suggest that TMDCs and their bulk heterojunctions are interesting photocatalytic systems which can also be employed to a variety of oxidation reactions, and they can be coupled with different reduction processes for solar-fuel production.