Review—The Variation of Anodization Conditions and the Structural Properties of Nanoporous Anodic Alumina (NAA) within Different Acidic Solutions

Abstract

The unique optical and electrochemical properties of nanoporous anodic alumina (NAA) have led to a wide range of applications such as desalination of seawater, biosensors, nucleic acid detection, photonic crystal lasers, etc. This paper reviews the fabrication conditions of NAA for electrochemical anodization in different acidic solutions, including three widely used acids (sulphuric, oxalic, and phosphoric) and some other acidic solutions. The structure and interpore distance properties of NAA can be varied by the type of electrolyte, concentration of electrolyte, voltage, current density, temperature, and anodizing time during the anodizing process.

Review of Catalysts, Substrates, and Fabrication Methods in Catalytic Hydrogen Combustion with Further Challenges and Applications

“…The variations of the anodization method will lead to different structures of nanopores. AAO can be functionalized by variable fabrication conditions, such as the temperature, voltage, and acid concentration through the electrochemical process, and different acids could affect different ranges of properties . In this case, the properties of AAO, such as interpore distance and pore diameter, can be varied to provide more suitable support material for CHC catalysts.…”

Superhydrophobicity‐mediated enhanced enzymatic kinetics and high‐performance bioassays

“…Porous anodic alumina (PAA), one of many porosint, with an ideally ordered channel arrangement that runs vertically throughout the whole membrane, has been extensively employed in abundant applications, including solar cells, biosensors, and template-assisted nanostructure manufacturing. 44,45 Based on these unique features, Mi et al 46 indicating that the enzymatic reaction kinetics are enhanced due to the fast and sufficient oxygen supply from the gas phase to the reaction interface. This work suggests that the triphase design and rational interface wettability control can improve the efficiency of gas-involved enzymatic reactions.…”

“…In oxidase‐based electrochemical bioassay system, a solid–liquid–air triphase electrode design based on porous structures can provide rapid and sufficient oxygen access as well as the catalytic reaction sites at the reaction interface, enabling improved oxidase reaction kinetics and a high‐performance biosensor. Porous anodic alumina (PAA), one of many porosint, with an ideally ordered channel arrangement that runs vertically throughout the whole membrane, has been extensively employed in abundant applications, including solar cells, biosensors, and template‐assisted nanostructure manufacturing 44,45 . Based on these unique features, Mi et al 46 fabricated a solid–liquid–air triphase electrode by modifying Au NPs‐loaded PAA membrane with n‐dodecanethiol (NDM) and further regulated the surface wettability with NDM or 11‐Mercaptoundecanoic acid.…”

Effect of Al Polishing Conditions on the Growth and Morphology of Porous Anodic Alumina Films

“…Anodic oxidation (anodization) of aluminum remains still one of the most popular methods for the fabrication of nanoporous oxide layers. – Among numerous advantages of this process, the ability to control the morphological features of the anodic aluminum oxide (AAO) layers by simply tuning the conditions at which the electrochemical process is carried out seems to be particularly significant. , It is widely known for almost three decades that highly ordered AAO can be successfully generated by a two-step anodization procedure . This approach is based on the fact that during the first anodization, an irregular oxide layer is initially created, which is accompanied by the formation of hexagonally distributed concaves on the Al substrates (pretexturization of the Al substrate).…”