Condensed Matter Physics Seminar

Prof. Pagona Papakonstantinou, Engineering Research Institute (ERI), School of Engineering, University of Ulster

Friday 10 January 2014, 1500-1600
C1 Physics Building

2 Dimensional materials as Non Precious Electrocatalysts for energy applications

Driven by growing concerns about global warming and the depletion of petroleum resources, the development of renewable energy production and storage technologies represents one of the major scientific challenges of the twenty-first century. A critical element in the pursuit of this quest is the discovery of efficient and cost-effective catalysts for accelerating electrochemical energy conversion processes such as the oxygen evolution reaction (OER), oxygen reduction reaction (ORR) and Hydrogen evolution reaction (HER), which are central to the efficiencies of solar or electrolytic water-splitting devices, fuel cells and metal-air batteries. All three reactions are sluggish in nature and traditionally require the use of precious metal catalysts. Thus, the focus of our work is to develop inexpensive, stable and catalytically active materials for the ORR, OER and HER reactions, that can compete the performance of precious based catalysts [1-5].

Defect engineering and interfacial coupling are fundamental pathways for achieving are highly catalytically active 2 Dimensional a few layered graphene and transition metal dichalcogenides. In this talk, I will give two examples of our efforts towards these directions including (i) strategies for increasing the edges of oxygen free graphene and MoSx nanosheets, and (ii) the strategic implementation of highly coupled graphene based hybrid systems, which can lead to unexpected and highly desirable properties for ORR, OER, and HER reactions.

[1] N. Shang, et al, "Catalyst-free efficient growth, orientation and biosensing properties of multilayer graphene nanoflake films with sharp edge planes ", Adv. Funct. Mater., 18 (2008) 3506.

[2] A. Ganguly, et al, "Probing the Thermal Deoxygenation of Graphene Oxide Using high resolution x ray spectroscopies", J. Phys. Chem. C, 115 (2011) 17009.

[3] N Shang, et al, "Controllable selective exfoliation of high-quality graphene nanosheets and nanodots by ionic liquid assisted grinding", Chem. Com., 48 (2012) 1877.

[4] T. Wang, et al, "Enhanced electrocatalytic activity for hydrogen evolution reaction from self-assembled monodispersed molybdenum sulfide nanoparticles on an Au electrode" Energy Environ. Sci., 6 (2013) 625.

[5] T. Wang et al, "Size‐Dependent Enhancement of Electrocatalytic Oxygen‐Reduction and Hydrogen‐Evolution Performance of MoS2 Particles", Chemistry-A European Journal 19 (2013) 11939.