Low-cost and eco-friendly fluidized bed hydrogen reduction assisted electroless plating to synthesize Ni-coated graphite

Abstract

Electroless plating is the main method for preparing metal-coated composite powders, such as Ni-coated graphite powders with wide applications in electromagnetic shielding materials, sealing coating, and electrocatalysis. However, the issues of uniform and dense coating during synthesis are hindering its practical implementation. Incorporating noble metals, such as Pd, to activate powders is a typical technique to prepare an electroless Ni coating. However, noble metal utilization is hindered by issues such as high costs and substantial wastewater. Herein, a novel low-cost and eco-friendly activation method based on fluidized bed hydrogen reduction is designed to prepare densely coated Ni@irregular graphite particles (Ni@IGP) using a low Ni content. This method can be used to construct a uniform and dense Ni coating for composite powders without acid alkali treatment and use of precious metals during the overall manufacturing process. Results demonstrated that the Ni@IGP particle obtained through this approach have good electrical conductivity and ferromagnetic properties. In addition, the uniformity and integrity of the Ni plating were adjusted, and the dense coating of graphite at a low Ni content of 35 wt% was effectively achieved. This new activation method sheds light on the field of electroless Ni plating on powders.