Electronic and optical properties of nitrogen-doped layered MnO 2, the non-defective, the N-substituted defective, and the N-substituted in conjunction with O-vacancy forms, are analyzed theoretically based on Density Functional Theory. We have found that (1) N-subsitution in both the monolayer and the stacked system gives rise to an acceptor-like state close to the conduction band, (2) O vacancy is beneficial for the formation of a substitutional NO defect, causing a stabilization of the doubly defective systems through a self-compensation mechanism, (3) the coexistence of both defects in the stacked system, resulting a quantitative energetic stabilization for the latter structure, and finally (4) the reduction of the oxidation state of Mn via N-doping reveals this process as extremely suitable to obtain catalysts with enhanced activity.
Electronic and Optical Properties of Nitrogen-Doped Layered Manganese Oxides
GIORGI, Giacomo;
2014
Abstract
Electronic and optical properties of nitrogen-doped layered MnO 2, the non-defective, the N-substituted defective, and the N-substituted in conjunction with O-vacancy forms, are analyzed theoretically based on Density Functional Theory. We have found that (1) N-subsitution in both the monolayer and the stacked system gives rise to an acceptor-like state close to the conduction band, (2) O vacancy is beneficial for the formation of a substitutional NO defect, causing a stabilization of the doubly defective systems through a self-compensation mechanism, (3) the coexistence of both defects in the stacked system, resulting a quantitative energetic stabilization for the latter structure, and finally (4) the reduction of the oxidation state of Mn via N-doping reveals this process as extremely suitable to obtain catalysts with enhanced activity.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
