MgO(111) nanosheets with unusual surface activity
MgO(111) nanosheets can be prepared via a facile wet chemical process. The MgO(111) nanosheets possessing the exposed (111) plane as a main surface have a thickness typically between 3 and 5 nm. Study of MgO(111) nanosheets by in situ diffuse reflectance Fourier transform (DRIFT) spectroscopy suggests that hydroxyl groups, oxygen vacancies, and surface oxygen anions exist on the surface and the (111) surface may be stabilized by hydroxyl groups. DRIFTS and temperature-programmed desorption (TPD) studies of CO2 adsorption reveal that there are large amounts of medium basic sites which can be attributed to the high concentration of surface O2- Lewis basic sites. DRIFTS and temperature-programmed reaction studies (TPRS) of methanol have demonstrated that, in contrast to commercial MgO, MgO(111) nanosheets are highly reactive toward the decomposition of methanol. Methanol can be decomposed and the surface C = O species formed can be oxidized readily at low temperature by the high concentration of oxygen anions on the surface of MgO(111) nanosheets, which demonstrates that these nanosheets have potential application in fuel cells and methanol-based alternative energy technologies.