Facile fabrication method and decent humidity sensing of anodised nanotubular Ta2O5 on Ta foil substrate

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

“…The composition and concentration of anodizing electrolytes significantly affect the morphology of ATO layers. − Electrolytes used for anodization of Ta can be broadly classified into three categories: (i) inorganic including, e.g., H 2 SO 4 , Na 2 SO 4 , H 3 PO 4 , HCl, NaBF 4 , H 2 CrO 4 , etc., (ii) organic acids, such as citric acid, oxalic acid, acetic acid, and (iii) mixtures of inorganic and organic electrolytes. − Earlier studies on anodization of Ta in two component electrolytes, e.g., H 2 SO 4 , Na 2 SO 4 , H 3 PO 4 , HCl, NaBF 4 , chromic acid, citric acid, etc. in water, resulted in the formation of a compact or barrier type oxide layer with the thicknesses of few nm. ,,−…”

“…In general, the morphology of anodic tantalum oxide layers can be categorized into four types: (a) a compact layer with a microstructural morphology, (b) nanodimple, (c) disordered porous, and (d) ordered nanoporous/nanotubular structure. − As discussed earlier, anodizing conditions like appropriate F – ions containing electrolytes, voltage range, and anodizing time are necessary to shape the metal oxide layer into a nanotube/nanopore geometry, and this can be correlated to an equilibrium condition between the oxide formation and its dissolution. In this section, we will discuss all possible growth mechanisms of ATO in electrolytes containing F – ions or free of F – ions.…”

“…The size, morphology, crystallinity, and impurity content of ATO or ATO-derived materials can significantly influence their physicochemical properties. ,− ,,,,,,,,,,,,,− Although ATO-based capacitors have been investigated since the 1980s/1990s, ,, in the last two decades, efforts have also been made to explore the potential of ATO-based materials in the fields of memristive devices, photocatalysis, electrocatalysis, corrosion resistant coatings, and biomedical applications. ,,,,,,,,,,,− In this section, we summarize some notable physiochemical properties and applications of ATOs or their derived materials.…”

“… 18 , 30 − 34 , 40 , 46 , 55 , 56 , 60 , 64 , 68 , 77 , 78 , 90 , 82 , 84 , 112 − 115 Although ATO-based capacitors have been investigated since the 1980s/1990s, 87 , 93 , 94 in the last two decades, efforts have also been made to explore the potential of ATO-based materials in the fields of memristive devices, photocatalysis, electrocatalysis, corrosion resistant coatings, and biomedical applications. 46 , 55 , 56 , 60 , 64 , 68 , 77 , 78 , 90 , 82 , 84 , 112 − 115 In this section, we summarize some notable physiochemical properties and applications of ATOs or their derived materials.…”

Properties and Application of Electrochemically Anodized Ta2O5 Nanostructures: A Review

“…This high surface area to volume ratio in the sensors provides highly effective interactions and bindings between active sites and water molecules [3]. This allows the potential of anodized Ta2O5 to be further explored as Ta2O5 has a good record for H + interaction while considering the nanostructure potential to enhance the water molecules interaction in humidity sensors [99].…”