Anodic film growth on Al layers and Ta–Al metal bilayers in citric acid electrolytes

Highly Ordered Anodic Porous Alumina Formation by Self‐Organized Anodizing

“…For anodic porous alumina, the film growth is associated with localized dissolution of the oxide, as a result of which pores are formed in the oxide film. However, the porous anodic layer formation has been recently reported for various acidic electrolytes such as malonic [209][210][211], tartaric [211][212][213], citric [214][215][216][217], malic [213], glycolic [213] and even chromic acid [218]. Anodic porous oxide films have been also obtained in unpopular electrolytes, including a mixed solution of phosphoric and organic acids with cerium salt [219], or in a mixture of oxalic acid, sodium tungstate, phosphoric and hypophosphorous acids [220].…”

Porous Aluminum Oxide Formed by Anodizing in Various Electrolyte Species

“…Citric acid (HOOC-CH 2 -C(OH)(COOH)-CH 2 -COOH) is very useful for fabrication of porous oxide films with large cell diameters [75][76][77][78] [86], and acetonedicarboxylic acid (HOOC-CH 2 -CO-CH 2 -COOH) at 150 V [86]. Because the formation of porous oxide films on aluminum is strongly affected by the acid dissociation constants of the electrolyte used, additional carboxylic electrolytes for porous oxide formation may be still found by examining dissociation constants in further research work [86].…”

Fabrication of Anodic Nanoporous Alumina via Acetylenedicarboxylic Acid Anodizing

“…Each electrolyte operates effectively at an appropriate anodizing voltage, which has a great effect on the cell size (identical meaning to interpore distance) and pore diameter of the resulting anodic porous alumina film 14,15 . Only a few inorganic and organic electrolytes, such as sulfuric (H 2 SO 4 ) 16 , phosphoric (H 3 PO 4 ) 17 , chromic (H 2 CrO 4 ) 18 , and several carboxylic acids, including oxalic acid ((COOH) 2 ) [19][20][21][22][23] , have been reported for porous alumina fabrication to date, and there has been no report on the development of a new anodizing electrolyte in recent decades. However, the discovery of additional electrolytes would greatly expand the applicability of anodic porous alumina.…”