Preparation of nanoporous Cu/Cu2O composites by anodic oxidation and their electrocatalytic performance towards methanol oxidation

Incorporation of Ions into Nanostructured Anodic Oxides—Mechanism and Functionalities

“…As a dihydric acid, oxalate presents delocalized π bonds which would be responsible for excitation in the ultraviolet region. According to Vrublevsky et al [105], the anion incorporation during the anodization is a result of two simultaneous reactions: water electrolysis and dissociation of a hydrogenoxalate anion (HC 2 O 4 − ) that results in the incorporation of oxygen and oxalate (C 2 O 4 2− ) anions inside the oxide structure [16,25]. Vrublevsky et al [105] also suggested that when Al is anodized in an oxalic acid solution, the formation of a bidentate coordination compound based on carboxylate ion and Al 3+ ions occurs.…”

“…The most significant applications of nanostructured oxides formed by the anodization of popular metals are presented in Figure 2. For example, copper anodizing contributes to such important applications as CO 2 electrochemical reduction [24], methanol fuel cells [25], photocatalytic water splitting [26] and microplastic decomposition [27]. Anodic titania is used in such important aspects as photocatalytic water splitting [28], hazardous compounds neutralization (e.g., Bisphenol A and Rhodamine B [29], or chromates [30]) and microplastic decomposition [31].…”

Porosity evolution and oxide formation in bulk nanoporous copper dealloyed from a copper–manganese alloy studied by in situ resistometry

“…as anode materials for lithium-ion batteries, [10][11][12] as catalysts [13][14][15] and for sensors. 16 In the literature, synthesis of npCu from AlCu, [16][17][18][19][20] SnCu, 11 TiCu, 21 CeCu, 22 NiCu, 17 ZnCu 17,23,24 and CuMn [25][26][27] has been reported, whereby the resulting nanoporous structures differ greatly depending on experimental parameters and alloy composition. Among them, nanoporous copper from copper-manganese gained a lot of interest as it exhibits one of the largest differences in electrochemical potential (difference of 1.477 V between Mn/Mn 2+ and Cu/Cu 2+ ) 28 from the alloys mentioned above.…”

“…Up to now, only a few studies are available which focus on the systematic understanding of the dealloying of this alloy system. Early investigations on the dealloying process and the porous structure of copper manganese alloys started in the 1980s, [29][30][31] but studies on microstructural composition of the porous structure 32,33 or electrocatalytic performance 13,25 have been performed only in recent years. Also, strong inuence of the pH-value and concentration 26,28,34 of the electrolyte as well as of previous heat treatment 35 has been reported.…”

“…At the same time, deliberate control of oxide formation is of great importance for many applications including energy storage and sensing. 14,25,25,36 Studies of the dealloying and the electrochemical performance of dealloyed npCu will signicantly contribute to the fundamental understanding of the structural evolution. There are several methods for investigating dealloying processes (including X-ray scattering, [37][38][39] X-ray diffraction, 40 and electron microscopy 41,42 ), but most methods are surface specic and focus on small volumes.…”