Hierarchically Nanostructured Rutile Arrays: Acid Vapor Oxidation Growth and Tunable Morphologies

Abstract

A general acid vapor oxidation (AVO) strategy has been developed to grow highly oriented hierarchically structured rutile TiO(2) nanoarrays with tunable morphologies from titanium thin films. This is a simple one-pot synthesis approach involving the reaction of a titanium surface with the vapor generated from a hydrochloric acid solution in a Teflon lined autoclave. To the best of our knowledge, this is the first successful attempt to grow ordered tree-like titania nanoarrays. A possible formation mechanism for the interesting architectures has been proposed based on series of time-dependent experiments. By adjusting the initial HCl concentration, films of different rutile structures including nanotrees, dendritic nanobundles, and nanorods can be selectively obtained. Subsequently, the surface morphologies and wettability can be readily tuned.

Effect of calcination on structural, morphological and photoelectrochemical performance of SnO2/TiO2 nanostructure films

“…However, these nanostructures have a low dye adsorption and hence small light harvesting efficiency because of large number of gaps existing among the wires. Yang et al [22] synthesized treelike TiO 2 nanoarrays on metal Ti foils but their application in DSSCs was limited [23] fabricated treelike TiO 2 nanostructures on SnO 2 via pulsed laser deposition for photoanodes in DSSCs and achieved a good light-to-electricity conversion efficiency. However, compare to vapor phase techniques, solutionbased methods are more appropriate for low cost mass production.…”

Hierarchical nitrogen and cobalt co-doped TiO2 prepared by an interface-controlled self-aggregation process

“…Since Kasuga reported the hydrothermal synthesis of titanate nanotubes [13], morphology-controlled titanate nanostructures, such as nanotubes [4,14], nanosheets [15,16] and nanorods [17], have been considerably explored. Particularly, many interesting nanostructures can be obtained by vapor-solid-liquid interface-controlled methods [18][19][20]. For example, Yang et al reported that hierarchically structured TiO 2 nanoarrays with tunable morphologies are synthesized via a general acid vapor oxidation strategy at the vapor-solid interface [19].…”

“…Particularly, many interesting nanostructures can be obtained by vapor-solid-liquid interface-controlled methods [18][19][20]. For example, Yang et al reported that hierarchically structured TiO 2 nanoarrays with tunable morphologies are synthesized via a general acid vapor oxidation strategy at the vapor-solid interface [19]. It has also been reported that thin films of metals, metal chalcogenides and oxides can be prepared by interfacial deposition schemes, and that the structural properties of the deposits, such as grain size and morphology, can be controlled by the reaction parameters [20].…”

Monodisperse rutile microspheres with ultrasmall nanorods on surfaces: Synthesis, characterization, luminescence, and photocatalysis

“…Park et al synthesized rutile TiO 2 nanobranches using a seeding method with TiO 2 nanowires as a seed [58]. Wu et al reported the assembly of rutile nanotree, nanoflower, and cross-medal arrays through a simple acid vapor oxidation (AVO) [59][60][61]. Despite these advances, the range of rutile TiO 2 geometries still needs to be expanded to meet the increasing nano-and microtechnological demands.…”