The influence of sulphide transport on the growth and properties of copper sulphide films on copper

• A novel experiment was designed to determine the interfacial sulphide concentration.
• The accelerated sulphide transport changed the structure and properties of films.
• The film growth mechanisms were proposed under stagnant and convective conditions.

The kinetics of Cu2S (chalcocite) film growth on corroding copper surfaces were monitored by following the change in pH in anaerobic aqueous sulphide solutions. Under stagnant conditions film growth was controlled by SH− diffusion in solution, and the formation of a non-protective film allowed complete consumption of available SH−. When accelerated by convection, film growth rapidly became controlled by Cu+ transport through a coherent protective film and proceeded at a considerably slower rate.