Interplay between Fe-Titanate Nanotube Fragmentation and Catalytic Decomposition of C2H4: Formation of C/TiO2 Hybrid Interfaces

Abstract

This paper reports the synthesis of Fe-titanate nanotubes by means of the conventional ion-exchange method with iron nitrate solutions. As the iron-rich nanotubes were found to contain the catalyst precursor intrinsically dispersed in their structures, the unprecedented possibility of using this kind of materials for building carbon nanostructures, firmly attached at the surface of the forming TiO 2 nanoparticles, was verified. The catalytic decomposition of ethylene, used as a carbon source, was performed at a relatively high temperature (750 • C) when the nanotubes undergo an irreversible phase transformation to form anatase and rutile nanoparticles. Due to the different amounts of Fe ions in the nanotubes, distinct types of carbon/TiO 2 hybrid interfaces were formed, ranging from amorphous (lower Fe 3+ concentration) to the more crystalline graphitic domains (higher Fe 3+ concentrations), as documented by the microstructure of the treated samples. The present approach is of potential interest for (photo)catalytic and energy conversion/transport applications.

Study of 1D Titanate‐Based Materials –New Modification of the Synthesis Procedure and Surface Properties‐Recent Applications

“…The decrease in the band gap energy may be ascribed to the progressive amount of doping iron ions that can form doping levels near the valence band of TiNTs. Iron species (Fe(III)) are present in different forms and as larger aggregates, which may be attributed to their increasing concentration within the solution. The same phenomena were observed in the case of Nitrogen‐doped TiNTs.…”

MoS2 Domains on TiO2-Based Nanostructures: Role of Titanate/TiO2 Transformation and Sulfur Doping on the Interaction with the Support

“…The formation of different nanostructures, coming from the fragmentation processes along and perpendicularly to the titanate nanotubes elongation direction becomes even more evident from HRTEM analyses (Figure c,d). It is known that the conversion of the HTNTs into the anatase phase by thermal dehydration causes the interlayer spacing between the walls to collapse with disappearing of the hollow cavity, , thus, giving rise to many different structures, including nanorods, anatase domains, and so on. As a matter of a fact, the HRTEM image (Figure c) shows collapsed nanostructures, as shown from the reduced interlayer spacing between the walls, (about 0.61 nm), compared to that of the original titanates nanotubes (0.69 nm).…”

Magnetic Materials and Systems: Domain Structure Visualization and Other Characterization Techniques for the Application in the Materials Science and Biomedicine

“…In the field of materials science, a multi-technique approach is often adopted by combining microscopies and spectroscopies together with other techniques. In this regard, the electron microscopies are more commonly used to determine the morphology and the structure, while the magnetic properties are revealed by complementary techniques [91,96,108,151].…”