Effect of heat treatment of Mn-Cu precursors on morphology of dealloyed nanoporous copper

Abstract

Nanoporous copper with nano-scale pore size was synthesized by dealloying Mn-Cu precursor alloy using a free corrosion method. The effects of heat treatment of Mn-Cu precursors on alloy phase, morphology and composition of the resultant nanoporous copper were investigated. It is revealed that the compositions distribute homogeneously in the bulk Mn-Cu precursors, which consequently results in a more fully dealloying for forming nanoporous copper. The alloy phase changes from Cu_0.49Mn_0.51 and Cu_0.21Mn_0.79 of non-thermally treated precursor to Cu_0.33Mn_0.67 of heat treated alloy. The residual Mn content in nanoporous copper is decreased from 12.97% to 2.04% (molar fraction) made from the precursor without and with 95 h heat treatment. The typical pore shape of nanoporous copper prepared by dealloying the precursor without the heat treatment is divided into two different zones: the uniform bi-continuous structure zone and the blurry or no pore structure zone. Nanoporous copper is of a uniform sponge-like morphology made from the heat-treated precursor, and the average ligament diameter is 40 nm, far smaller than that from the non-thermally treated precursor, in which the average ligament diameter is estimated to be about 70 nm.

Keywords

nanoporous copper / preparation / dealloying / heat treatment / morphology

References

[1] DingY., KimY. J., ErlebacherJ.. Nanoporous gold leaf: “Ancient technology” [J]. Advanced Materials, 2004, 16(21): 1897-1900

[2] VolkertC. A., LilleoddenE. T., KramerD., WeissmüllerJ.. Approaching the theoretical strength in nanoporous Au [J]. Applied Physics Letters, 2006, 89: 061920

[3] ErtenbergR. W., AndrakaB., TakanoY.. Prospects of porous gold as a low-temperature heat exchanger for liquid and solid helium [J]. Physica B, 2000, 2022: 284-288

[4] ZielasekV., JÜRGENSB., SchulzC., BienerJ., MonikaM. B., HamzaA. V., BÄUMERM.. Gold catalyst: Nanoporous gold foams [J]. Angew Chem Int Ed, 2006, 45: 8241-8244

[5] XuC.-x., XuX.-h., SuJ.-x., DingY.. Research on unsupported nanoporous gold catalyst for CO oxidation [J]. Journal of Catalysis, 2007, 252: 243-248

[6] ZeisR., MathurA., FritzG., LeeJ., ErlebacherJ.. Platinum-plated nanoporous gold: An efficient, low Pt loading electrocatalyst for PEM fuel cells [J]. Journal of Power Sources, 2007, 165: 65-72

[7] ErlebacherJ., AzizM. J., KarmaA., DimitrovN., SieradzkiK.. Evolution of nanoporosity in dealloying [J]. Nature, 2001, 410: 450-453

[8] ErlebacherJ., SieradzkiK.. Pattern formation during dealloying [J]. Scripta Materialia, 2003, 49: 991-996

[9] LuX., BalkT. J., SpolenakaR., ArztE.. Dealloying of Au-Ag thin films with a composition gradient: Influence on morphology of nanoporous Au [J]. Thin Solid Films, 2007, 515: 7122-7126

[10] LuX., BischoffE., SpolenakaR., BalkT. J.. Investigation of dealloying in Au-Ag thin films by quantitative electron probe microanalysis [J]. Scripta Materialia, 2007, 56: 557-560

[11] HakamadaM., MabuchiM.. Microstructural evolution in nanoporous gold by thermal and acid treatments [J]. Materials Letters, 2008, 62: 483-486

[12] SeniorN. A., NewmanR. C.. Synthesis of tough nanoporous metals by controlled electrolytic dealloying [J]. Nanotechnology, 2006, 17: 2311-2316

[13] ParidaS., KramerS., VolkertC. A., RÖSNERH., ErlebacherJ., WeissmüllerJ.. Volume change during the formation of nanoporous gold by dealloying [J]. Physics Review Letters, 2006, 97: 035504

[14] ThorpJ. C., SieradzkiK., TangLei.. Formation of nanoporous noble metal thin films by electrochemical dealloying of Pt_xSi_1−x [J]. Applied Physics Letters, 2006, 88: 033110

[15] PughD. V., DursunA., CorcoranS. G.. Formation of nanoporous platinum by selective dissolution of Cu from Cu_0.75Pt 0.25 [J]. Journal of Materials Research, 2003, 18(1): 216-221

[16] MeyerheimH. L., SoykaE., KirschnerJ.. Alloying and dealloying in pulsed laser deposited Pd films on Cu(100) [J]. Physical Review B, 2006, 74: 085405

[17] BayoumiF. M., AteyaB. G.. Formation of self-organized titania nano-tubes by dealloying and anodic oxidation [J]. Electrochemistry Communications, 2006, 8(1): 38-44

[18] HayesJ. R., HodgeA. M., BienerJ., HamzaA. V., SieradzkiK.. Monolithic nanoporous copper by dealloying Mn-Cu [J]. Journal of Materials Research, 2006, 21(10): 2611-2616

[19] LuH., LiY., WangF.. Synthesis of porous copper from nanocrystalline two-phase Cu-Zr film by dealloying [J]. Scripta Materialia, 2007, 56: 165-168

[20] MinU. S., LiJ. C. M.. The microstructure and dealloying kinetics of a Cu-Mn alloy [J]. Journal of Materials Research, 1994, 9: 2878-2883

[21] SekerE., GaskinsJ. T., Bart-smithH., ZhuJ., ReedM. L., ZangariG., KellyR., BegleyM. R.. The effects of annealing prior to dealloying on the mechanical properties of nanoporous gold microbeams [J]. Acta Materialia, 2008, 56: 324-332

[22] KucheyevS. O., HayesJ. R., BienerJ., HuserT., TalleyE., HamzaA. V.. Surface-enhanced Raman scattering on nanoporous Au [J]. Applied Physics Letters, 2006, 89: 053102