Electrocatalytic reduction of CO2 to CO by Gd(III) and Dy(III) complexes; and M2O3 nanoparticles (M = Gd and Dy)

Surface thermodynamics of yttrium titanate pyrochlore nanomaterials

Nanocrystalline pyrochlore materials have been investigated for their enhanced radiation tolerance as ceramic nuclear waste hosts. In this work, we study the thermodynamic driving force of nano-scale materials for radiation resistance. The size dependent thermodynamic properties of a series of Y2Ti2O7 nanoparticles were investigated. Samples were synthesized by a sol-gel method and characterized by synchrotron X-ray diffraction, BET analysis, and thermogravimetric analysis. The surface and interface enthalpies of Y2Ti2O7 were determined by high temperature oxide melt drop solution calorimetry to be 4.07 J m-2 and 3.04 J m-2, respectively. The experimentally obtained surface energy is in good agreement with computationally derived average surface energies for yttrium and other rare-earth titanate pyrochlores. Theoretical links between nanoparticle stability, surface energy, and radiation resistance of pyrochlore materials were then explored.

Rare-Earth Doping in Nanostructured Inorganic Materials

Impurity doping is a promising method to impart new properties to various materials. Due to their unique optical, magnetic, and electrical properties, rare-earth ions have been extensively explored as active dopants in inorganic crystal lattices since the 18th century. Rare-earth doping can alter the crystallographic phase, morphology, and size, leading to tunable optical responses of doped nanomaterials. Moreover, rare-earth doping can control the ultimate electronic and catalytic performance of doped nanomaterials in a tunable and scalable manner, enabling significant improvements in energy harvesting and conversion. A better understanding of the critical role of rare-earth doping is a prerequisite for the development of an extensive repertoire of functional nanomaterials for practical applications. In this review, we highlight recent advances in rare-earth doping in inorganic nanomaterials and the associated applications in many fields. This review covers the key criteria for rare-earth doping, including basic electronic structures, lattice environments, and doping strategies, as well as fundamental design principles that enhance the electrical, optical, catalytic, and magnetic properties of the material. We also discuss future research directions and challenges in controlling rare-earth doping for new applications.