A clean method to obtain a porous alumina template

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.…”

Synthesis and enhancement of red UC luminescence properties of ordered hexagonal NaYF 4 :Yb 3+ /Er 3+ nanowire arrays

“…Through-hole AAO templates were prepared using high purity aluminum foil in 0.3 mol L −1 H 2 C 2 O 4 under 40 V at 0-5 • C via a two-step anodization process as described in the literature [17]. In our experiment, a through-hole AAO template was immersed into a 2 mol L −1 Ln 3+ (Y 3+ :Er 3+ :Yb 3+ = 77:3:20) solution (10 mL), and evacuated for about 15 min using a pump to get ride of bubbles within the nanopores.…”

“…In addition, the as-prepared templates can easily achieve excellent long range order [15]. The AAO templates, which possess uniform and parallel pores structure, is one of the most important templates for preparation of nanoarrays [16][17][18]. Previous studies showed that magnetite-doped rare earth fluoride nanotube arrays can be prepared by the impregnation of ␣-NaYF 4 :Yb 3+ /Er 3+ nanocrystals into the channels of the AAO template upon evaporation of the solvent on a 2-D solid substrate [19].…”

Formation of dense alumina nanowires from anodic alumina membranes

“…The templates were fabricated from high purity (99.99%) aluminium foils by applying a two-step anodizing process [1,10,11]. Anodization was conducted under constant cell potential of 40 V in a 0.3 M oxalic acid electrolyte.…”

“…In our previous work [10], we demonstrated that a complete dissolution of the AAO template can be achieved by immersing the membrane in a 2 M H 3 PO 4 acid solution. During this study we observed that prior to the complete dissolution, alumina nanowires were formed.…”