CVD Synthesis of Monodisperse Graphene/Cu Microparticles with High Corrosion Resistance in Cu Etchant

Shuangyi Li,Baosen Hou,Yi Ding,Dan Dai,Qiang Wang,Shengcheng Shu,Ao Li,Qiang Zhang,Yu Han,Nan Jiang,Zhi-Xiang Zhu,Cheng-Te Lin,Bao-An Chen,Mingliang Wu

doi:10.3390/ma11081459

Abstract

Copper powder has broad applications in the powder metallurgy, heat exchanger, and electronic industries due to its intrinsically high electrical and thermal conductivities. However, the ease of formation of surface oxide or patina layer raises difficulty of storage and handling of copper powder, particularly in the case of Cu microparticles. Here, we developed a thermal chemical vapor deposition chemical vapor deposition (CVD) process for large-scale synthesis of graphene coatings on Cu microparticles, which importantly can remain monodisperse without aggregation after graphene growth at high temperature by using removal spacers. Compared to other protective coating methods, the intrinsic electrical and thermal properties of Cu powder would not be degraded by uniform growth of low defect few-layer graphene on each particle surface. As a result, when the anticorrosion performance test was carried out by immersing the samples in Cu etchant, the corrosion rate of graphene/Cu microparticles was significantly improved (ca three times slower) compared to that of pristine Cu powder, also showing a comparable anticorrosion ability to commercial CuZn30 alloy.

Highlights

Copper powder is an industrial raw material for the fabrication of various electrically and thermally conductive components, such as pantograph contact strips, electrical connectors, and heat sinks [1,2,3]
After 1 h reaction, we found that the pristine Cu powder was completely dissolved, whereas a lot of graphene-coated Cu (Gr/Cu) microparticles still remained unaffected, indicating a significant improvement of corrosion resistance of Cu microparticles coated with few-layer graphene
We developed a facile chemical vapor deposition (CVD) process for the synthesis of monodisperse Gr/Cu microparticles in a large quantity using graphite particles as removal spacers, by which the particle microparticles in a large quantity using graphite particles as removal spacers, by which the particle size of the obtained products is similar to that of Cu powder and no aggregation is observed, even size of the obtained products is similar to that of Cu powder and no aggregation is observed, though the CVD temperature is close to the melting point of copper

Summary

Introduction

Copper powder is an industrial raw material for the fabrication of various electrically and thermally conductive components, such as pantograph contact strips, electrical connectors, and heat sinks [1,2,3]. The widespread applications of copper powder are due to the high electrical (6.0 × 107 S/m) and thermal conductivities (κ: 400 W/mK) after sintering to bulk, and both are only lower than those of silver (6.3 × 107 S/m and 420 W/mK, respectively) among metals [4,5]. Parra et al demonstrated that the Ni surface with graphene coating grown by CVD corrodes five times slower than that covered with mechanically transferred graphene [19] It suggests that the growth of CVD graphene on copper powder might be able to efficiently protect the surface from oxidation/corrosion, and not degrade the intrinsic electrical/thermal properties. The formation of high-quality, low-defect graphene on the surface of copper powder without aggregation is of major importance for the development of potential anticorrosion applications. CuZn30 alloy when the samples were immersed in Cu etchant, demonstrating superior anticorrosion ability of Gr/Cu microparticles

Experimental

Results and Discussion

Conclusions