Browsing by Author "Chu, D"
Now showing 1 - 3 of 3
Results Per Page
Sort Options
- ItemFerromagnetic ordering in Mn-doped ZnO nanoparticles(Springer, 2014-01-01) Luo, X; Lee, WT; Xing, GZ; Bao, N; Yonis, A; Chu, D; Lee, J; Ding, J; Li, S; Yi, JBZn1 - xMn x O nanoparticles have been synthesized by hydrothermal technique. The doping concentration of Mn can reach up to 9 at% without precipitation or secondary phase, confirmed by electron spin resonance (ESR) and synchrotron X-ray diffraction (XRD). Room-temperature ferromagnetism is observed in the as-prepared nanoparticles. However, the room-temperature ferromagnetism disappears after post-annealing in either argon or air atmosphere, indicating the importance of post-treatment for nanostructured magnetic semiconductors.© 2014 Luo et al.; licensee Springer.
- ItemReversible hydrophobic to hydrophilic transition in graphene via water splitting induced by UV irradiation(Macmillan Publisher, 2014-09-01) Xu, ZM; Ao, ZM; Chu, D; Younis, A; Li, CM; Li, SAlthough the reversible wettability transition between hydrophobic and hydrophilic graphene under ultraviolet (UV) irradiation has been observed, the mechanism for this phenomenon remains unclear. In this work, experimental and theoretical investigations demonstrate that the H2O molecules are split into hydrogen and hydroxyl radicals, which are then captured by the graphene surface through chemical binding in an ambient environment under UV irradiation. The dissociative adsorption of H2O molecules induces the wettability transition in graphene from hydrophobic to hydrophilic. Our discovery may hold promise for the potential application of graphene in water splitting. © 2014 Macmillan Publishers Limited
- ItemSegregation-induced low-dimensional surface structures in oxide semiconductors(Springer-Verlag Berlin Heidelberg, 2014-03-01) Atanacio, AJ; Bak, T; Chu, D; Ionescu, M; Nowotny, JThe present work considers quasi-isolated low-dimensional surface structures, which are formed as a result of segregation of intrinsic and extrinsic defects in oxide semiconductors. It has been documented that the local properties of these structures, such as crystalline structure, electronic structure, chemical composition, as well as charge and mass transport kinetics, are entirely different from those of the bulk phase. There is an increasingly urgent need to better understand their local properties, which have a strong impact on the reactivity of solids in general and photocatalytic properties in particular. The accumulation of data on the properties of surface structures opens a new discipline of the science of materials interfaces. The present work is focused on the surface structures, which are formed at TiO2-based semiconductors. It is shown that these structures play crucial role in the conversion of solar energy into chemical energy. © 2014, Springer-Verlag Berlin Heidelberg.