vLi Cequn, an undergraduate in the Department of Physics at Southern University of Science and Technology (SUSTech), recently published his research on how to enhance surface reactivity of metal oxides, titled “Surface Reactivity Enhancement by O2 Dissociation on a Single-layer MgO Film Deposited on Metal Substrate”, in the Journal of Chemical Physics, an international academic journal run by the American Institute of Physics (AIP). In this manuscript, Li Cequn was the first author and Xu Hu, an associate professor of the Department of Physics, acted as his adviser.
A student in the Department of Physics who was admitted to SUSTech in 2013, Li Cequn entered the research group at the end of his junior year to start related research work.
It has been a long time that the interaction of oxygen molecules with metal oxide surface has received widespread attention due to its important applications in chemical sensing, chemical catalysis, photocatalysis and other domains. From the perspective of the molecular level, the activation and dissociation of oxygen molecules on the surface of metal oxides is of great significance to reveal surface catalytic reaction. The surface of magnesium oxide (100) is a typical surface of metal oxide, with very low surface reactivity. Researches show in recent years that the growth of magnesium oxide film on metal substrates can significantly enhance the surface reactivity and activate oxygen molecules adsorbed on the surface, but it is still hard to enable O2 dissociation. In his research, Li Cequn made calculations through first principles and found that as the thickness of magnesium oxide film decreases to a molecular layer, the adsorption behavior of oxygen molecules on the surface changes, causing oxygen to be fully dissociated and diffused into interface area. The articles further pointed out that a single dissociated oxygen atom can serve as a switch to control the surface chemical reaction. To take water dissociation as an example, oxygen atoms at the interface can cause water molecules adsorbed on the surface to be dissociated, thus generating hydroxyl radicals.This research enables the dissociation of O2 on insulating surface for the first time, which then significantly promotes the catalytic reaction existing on corresponding surface. The reviewer set a high value on the work Li Cequn had done and pointed out in the review report: “The theoretical results presented in this manuscript clearly show important scientific knowledge and physical insights for the development of catalysts to improve chemical activities of oxygen and water molecules on metal-supported ultrathin oxide surfaces.” Prof. Gianfranco Pacchioni, a world-known surface physics expert, sent an email to express his great interest in the work and invited Li Cequn to make an academic visit to University of Milano Bicocca in Italy in February 2017 for two months.
The work has been supported by the National Natural Science Foundation of China and the Basic Research Project of Shenzhen Scientific and Technological Innovation Committee.
website: http://scitation.aip.org/content/aip/journal/jcp/145/16/10.1063/1.4965433
