A review on TiO2 nanotubes: synthesis strategies, modifications, and applications

Review of Anodic Tantalum Oxide Nanostructures: From Morphological Design to Emerging Applications

“…Later on, the same research group undertook further optimization of the HF content in the electrolyte, aiming to produce porous tantalum oxide films with highly regular pore arrays featuring about 20 nm pore diameters. , It was hypothesized that the interplay between pore formation and dissolution plays a critical role in the development of pores, order arrangement, and the thickness of the resulting oxide layer. ,− SEM images of the materials prepared in this study are presented in Figure , which once again indicates a pivotal role of HF concentration in the generation of the nanoporous structure . This study also sheds light on the influence of other anodizing parameters on the oxide morphology, namely extending the duration of anodization (from 1 to 4 h) increases both the pore diameter (from 5 to 35 nm) and thickness (from 160 to 800 nm) of the porous ATO layer.…”

“…Similar to the anodization of Ti, it is presumed that the anodization of Ta in the presence of F – may progress through the following steps. ,,,− As mentioned earlier, when anodization starts, a compact oxide layer of TaO x forms on the surface of tantalum. ,, As the anodization progresses, the formation of pores occurs due to both phenomena, dissolution of oxide at the oxide/electrolyte interface and generation of stress at the metal/oxide interface. However, the first of these factors is more important in the initial formation of pores, , and resulting Ta ions (Ta 5+ ) appearing at the oxide/electrolyte interface, are soluble by forming [TaF 7 ] 2– . , This process creates pores on the surface of the metal oxide films.…”

“…However, the first of these factors is more important in the initial formation of pores, , and resulting Ta ions (Ta 5+ ) appearing at the oxide/electrolyte interface, are soluble by forming [TaF 7 ] 2– . , This process creates pores on the surface of the metal oxide films. It is hypothesized that the complex [TaF 7 ] 2– , having a lower charge-to-size ratio compared to the F – ions, can easily be replaced by the electro-migrated F – ions from the bulk solution. ,− Thus, a new interface between oxide pores and electrolyte (specifically F – ions) forms, and the above process repeats in a continuous manner during the entire length of anodization, potentially deepening the pores. The growth rate of nanoporous/nanotube structures may be determined by the diffusion rate of the [TaF 7 ] 2– complex and F – ions. , It is predicted that the nanoporosity could be related to the molecular dimension of [TaF 7 ] 2– and the formation kinetics of Ta 2 O 5 .…”

An Overview of Hydrothermally Synthesized Titanate Nanotubes: The Factors Affecting Preparation and Their Promising Pharmaceutical Applications

“…Moreover, TNTs offer a distinguished profile of specifications that could be interesting in numerous fields, such as their hydrophilic nature, good wettability and biocompatibility [2,3,5], chemical stability [5], photocatalytic activity [5], excellent mechanical properties, and corrosion resistance [5,6], in addition to low toxicity [7][8][9][10]. Due to these remarkable specifications, TNTs have been successfully utilized in numerous fields with great outcomes and impressive performance (Figure 1) making them attractive candidates for investigation of their potentials in further disciplines [5,[11][12][13]. Although some attempts have been made to investigate the possible application of these newly synthesized materials in biomedical research, few of them have focused on their application in the pharmaceutical field as drug carriers [5,[14][15][16][17].…”

Electrochemical and Mechanical Properties of Hexagonal Titanium Dioxide Nanotubes Formed by Sonoelectrochemical Anodization

“…Recently, titanium surface technology has evolved from bioinert surfaces such as porous titanium [13] to bioactive surfaces such as nanotextured surfaces [14]. Titanium dioxide nanotubes (TNTs) have become a focal point in titanium surface modification, offering self-organized arrays of nanoscale pores via anodization [15].…”