Tunable Cu₂O Nanocrystals Fabricated by Free Dealloying of Amorphous Ribbons

Abstract

This work discovers that Cu 2 O nanocrystals with controllable structures can be synthesized on surfaces of nanoporous Cu and amorphous ribbons by free dealloying of Cu-based amorphous alloys in acidic solutions. Technological parameters, such as the acid, acid concentration, and dealloying time strongly influence the crystal size, structure and morphology of Cu 2 O. Cu 2 O nanocubes are fabricated on surfaces of nanoporous Cu in the hydrofluoric acid treated alloy, while various Cu 2 O particles are tailored on surfaces of amorphous alloys immersed in hydrochloric acid for different time. The increasing dealloying time and adsorbed oxygen improve the growth rates along the 1 0 0 direction of Cu 2 O crystals relative to that of the 1 1 1 direction, which is the key to change the shapes of Cu 2 O crystals. The understanding of morphology evolution of Cu 2 O nanocrystals in this work is helpful in tailoring Cu 2 O particles with designable shapes and controllable properties in application fields.

Tailored Dealloying Products of Cu-based Metallic Glasses in Hydrochloric Acid Solutions

“…With the increase of the dealloying time, the Route 1 and Route 2 will further proceed. The oxygen dissolved in the electrolyte is strongly adsorbed on the fresh copper surface (Equation 2 16,20 , further confirms the occurrence of the disproportionation reaction in Figure 1 and Table 1). The key factor for forming Cu 2 O crystals with different shapes can be attributed to the value of R [22] , which represents the growth rate of Cu 2 O particles along the <1 0 0> direction relative to that of the <1 1 1> direction.…”

“…However, the broad peak disappears after dealloying for 12 h or longer time, which demonstrates that glassy structure is destroyed for the Cu 52.5 Hf 40 Al 7.5 metallic glasses dealloyed in concentrated HCl solution for a long time. When dealloying for 12 h, Figure 2b reveals that only peaks matching with This work [20] This work [20] This work [20] [20] [20] fcc Cu (111), (200) Figure 3. Considering XRD results, as shown in Figure 2b, it is interestingly found that a nanoporous Cu structure in Figure 3a is produced by the accumulation of Cu nanospheres with diameter of 70-90 nm during the 12-hour dealloying.…”

“…Unfortunately, few studies focused on the other dealloying products obtained from these precursors in HCl solutions 20,21 . In this paper, in order to systematically investigate the correlation between the dealloying products and the dealloying conditions, free dealloying of Cu-Hf-Al metallic glasses in both diluted and concentrated HCl electrolytes for different time are carried out.…”

Dealloying of Cu-Based Metallic Glasses in Acidic Solutions: Products and Energy Storage Applications

“…As we know, the cost must be taken into account for practical commercial application of the dealloyed products. Recently, a new series of dealloyed products including nanoporous Cu (NPC) and nano/micro-Cu oxides with low cost and unique properties have been developed in our group [ 30 , 31 , 32 , 33 , 34 ]. This paper presents an overview of our recent advancement of dealloyed products via free-dealloying Cu-based metallic glasses (MGs) in hydrofluoric acid (HF) and hydrochloric acid (HCl) solutions, as well as a brief review of others’ results related to dealloying.…”

Synthesis of Cu xO(x = 1,2)/amorphous compounds by dealloying and spontaneous oxidation method

“…Nowadays, some studies reveal that dealloying method can be extended to the fabrication of metal oxide nanostructures with intricate structural properties. Fascinating nanostructures, such as Cu 2 O nanocubes 1,5 , octahedral Fe 3 O 4 and Mn 3 O 4 nanoparticles 6 , are successfully produced by dealloying method.…”