Addressing Complex Transition Metal Oxides at the Nanoscale: Bottom‐Up Syntheses of Nano‐objects and Properties

Abstract

An impressive library of functional oxide nanomaterials is now available, encompassing multicompartment nanoparticles and heterostructures in general that enable further tuning of the properties. Nonetheless, the vast majority of these nano-objects is built on relatively common oxides, easily synthesized at the nanoscale by chemical methods known since decades. This range of nanoscaled oxides is narrow compared to the library of bulk oxides. Extending the portfolio of oxide compositions at the nanoscale is mandatory to strengthen research efforts on the role of the nanoscale on the properties, and on the emergence of new properties. This chapter provides an overview of the synthesis techniques developed since few years to address complex oxide nanomaterials, encompassing multicationic oxides, oxides of metals with uncommon oxidation states, and new oxide crystal structures accessible only at the nanoscale.For each case, we illustrate the relevance of targeting such complex oxides by discussing their specific properties. doctoral researcher. His main interest is the synthesis design of multifunctional nanomaterials for their application in electrocatalysis.

Emerging trends in metal oxide-based electronic noses for healthcare applications: a review

“…Bottom-up strategies excel in their precision, creating structures atom by atom and resulting in materials with properties finely tuned to the requirements of gas sensing. 70 These techniques typically produce metal oxides with increased surface area and enhanced chemical functionality, critical attributes for the sensitivity and specificity required in E-nose systems.…”

Metal–Support Interactions in Pt-WO3 Heterostructures: Role of WO3 Polymorphism

“…2 Hexagonal tungsten bronzes reported to date are mostly referred to as the h form, while bronzes with the h′ framework have been reported only for protons inserted in the channels. 12 The relatively large channels of the h′-WO 3 hexagonal structure (5.1 Å) should enable hosting various cations, like in the h-WO 3 framework. 1,10,13 This characteristic makes them potential candidates in applications based on ion intercalation/ deintercalation processes, such as electrochromic devices where ion intercalation leads to tungsten reduction and then optical absorption modification.…”

“…In hexagonal bronzes, these cations are primarily located inside the hexagonal tunnels formed by six WO 6 octahedra sharing corners (Figure ). Occasionally, smaller tunnels, made up of four or three interconnected octahedra, can also host additional cations. − Presently, two different hexagonal polymorphs of WO 3 , h- WO 3 , and h ′-WO 3 (Figure ), differing in the arrangement of the octahedral units connecting the hexagonal tunnels, have been described. The latter, h ′-WO 3 framework, has been recently reported .…”

“…The latter, h ′-WO 3 framework, has been recently reported . Hexagonal tungsten bronzes reported to date are mostly referred to as the h form, while bronzes with the h ′ framework have been reported only for protons inserted in the channels …”