Electrodeposition of Palladium Film on Electroless Ni-P Coatings Supported by Si Substrate

A transition layer of Ni-P coating will help enhance the hydrogen sensing stability of Pd films supported by silicon wafers. In this work, Pd films were electrodeposited on electroless Ni-P coated silicon wafers. The effect of deposition parameters on the microstructure (especially the morphology) of Ni-P coatings and Pd films were investigated. Experimental results indicated that a lower pH value of electroless plating solution and a longer electroless plating time could increase the size of Ni-P nodular particles. In addition, the morphology of Pd films was shaped by the nanostructures of the Ni-P coating. An optimized Pd/Ni-P structures is expected to present good hydrogen sensing performance.