The thermally driven orders-of-magnitude modulation of resistance and optical transmittance observed in VO2 makes it an archetypal first-order phase transition material and underpins functional applications in logic and memory circuitry, electromagnetic cloaking, ballistic modulation, and thermochromic glazing to provide just a few representative examples. VO2 can be reversibly switched from an insulating to a metallic state at an equilibrium transition temperature of 67 °C. Tuning the phase diagram of VO2 to bring the transition temperature closer to room temperature has been a longstanding objective and one that has tremendous practical relevance. Substitutional incorporation of dopants has been the most common strategy for modulating the metalinsulator transition temperature but requires that the dopants be incorporated during synthesis. Here we demonstrate a novel postsynthetic diffusive annealing approach for incorporating interstitial B dopants within VO2. The postsynthetic method allows for the transition temperature to be programmed after synthesis and furthermore represents an entirely distinctive mode of modulating the phase diagram of VO2. Local structure studies in conjunction with density functional theory calculations point to the strong preference of B atoms for tetrahedral coordination within interstitial sites of VO2; these tetrahedrally coordinated dopant atoms hinder the rutile → monoclinic transition by impeding the dimerization of V–V chains and decreasing the covalency of the lattice. The results suggest that interstitial dopant incorporation is a powerful method for modulating the transition temperature and electronic instabilities of VO2 and provides a facile approach for postsynthetic dopant incorporation to reach a switching temperature required for a specific application.

Galvanostatic electrodeposition from Grignard reagents in symmetric Mg–Mg cells is used to map Mg morphologies from fractal aggregates of 2D nanoplatelets to highly anisotropic dendrites with singular growth fronts and entangled nanowire mats.

Unconventional deposits such as extra heavy oil and bitumen represent a steadily increasing proportion of extracted fuels. The rheological properties of viscous crude oil represents a formidable impediment to their extraction, transportation, and processing and have necessitated considerable retooling and changes to process design. In this work, we demonstrate that highly textured inorganic substrates generated by depositing ZnO nanotetrapods onto periodically ordered stainless steel mesh substrates exhibit viscous oil contact angles exceeding 150°as well as enable the facile gliding of viscous oil. Such functionality is derived as a result of multiscale texturation and porosity achieved within these substrates, which are characterized by trapping of plastronic air pockets at the solid/liquid interface. Further reduction of the surface energy has been achieved by constituting a helical highly ordered self-assembled monolayer of a perfluorinated phosphonic acid on the ZnO surfaces. Such structures are strongly ejected upon immersion in water with water contact angles in excess of 160°. The functionalized substrates demonstrate remarkable superoleophobic behavior toward viscous crude oil with contact angles reaching 156°and are furthermore stable to temperatures of 290 °C. The remarkable results evidenced here hold promise for deployment of these constructs in the handling of viscous oil in order to reduce losses associated with transportation from railroad cars, pipelines, and other oil-handling equipment.