Electroless Ni–W–Cr–P alloy coating with improved electrocatalytic hydrogen evolution performance

Abstract

The quaternary Ni–W–Cr–P alloy coatings were deposited on copper alloy by an electroless deposition process. Micromorphology, microstructure and hydrogen evolution reaction (HER) activity of electroless Ni–W–Cr–P coatings were examined. X-ray diffraction analysis showed that the Ni–W–Cr–P coatings were solid solution, and crystallisation started to occur with increasing heat treatment temperature. The experimental results also revealed that HER activity of the Ni–W–Cr–P coatings was enhanced compared with those of the uncoated. Moreover, with increasing annealing temperature, HER activity of the Ni–W–Cr–P coatings varied slightly. When heated at 500°C, the electrode got the best Tafel slope of 144 mV/decade and quite small overpotentials of 354 and 479 mV at the current densities of 10 and 30 mA cm⁻² respectively. Electroless deposition is a good way to get alloy coating, which can improve the electrocatalytic activity of the hydrogen generation efficiently.

Keywords:

• Electroless deposition
• Nickel–tungsten–chromium–phosphorus alloy coatings
• Heat treatment
• Microstructure
• Hydrogen evolution