Vanadium dioxide (VO2) is a Mott phase transition compound that can be applied as a thermochromic

smart material for energy saving and comfort, and titanium dioxide (TiO2) is a well-known photocatalyst for

self-cleaning coatings. In this paper, we report a VO2@TiO2 core-shell structure, in which the VO2 nanorod

core exhibits a remarkable modulation ability for solar infrared light, and the TiO2 anatase shell exhibits

significant photocatalytic degradation of organic dye. In addition, the TiO2 overcoating not only increased

the luminous transmittance of VO2 based on an antireflection effect but also modified the intrinsic color

of VO2 films from yellow to light blue. The TiO2 also enhanced the chemical stability of VO2 against

oxidation. This is the first report of such a single nanoparticle structure with both thermochromic and

photocatalytic properties that offer significant potential for creating a multifunctional smart coating.

Here in our following paper, we demonstrate that the Mott phase transition characteristics in VO2 nanoparticles can be remarkably modified by misfit strains occurring at the epitaxial interface between VO2 and the anatase TiO2 of VO2/TiO2 core−shell particles. The heteroepitaxial growth of the as-synthesized particles followed an unprecedented orientation relationship, and an epitaxial growth mechanism is proposed to explain this behavior. A relatively small theoretical coherent misfit (3−11%) and a moderate heating rate (20 °C·min−1) in the preparation of the core−shell structure were critically important from the thermodynamic and kinetic perspectives, respectively. The misfit-induced interfacial strain along the uniaxial cR axis increased the transition temperatures, especially on the cooling portion of the heating−cooling cycle, leading to a notably reduced transition hysteresis loop width (from 23.5 to 12.0 °C). Moreover, the optical band gap was also engineered by the interfacial effect. Such a reduced hysteresis showed a benefit for enhancing a rapid response for energy saving thermochromic smart windows.