Highly corrosion resistant platinum-rhodium alloy coating and its photocatalytic activity

Abstract

A method of electroplating a platinum–rhodium (Pt-Rh) alloy coating with a specified composition on a metal substrate stainless steel (SS304) is presented in this article. The Pt-Rh bath consists of [Pt (NH3)2]HPO4, H2SO4 and Rh2(SO4)3. The Pt-Rh alloy electrodeposition coatings were characterized by different analytical methods such as Scanning Electron Microscopy (SEM) and X-ray diffraction (XRD). SEM images justify that coating is uniform in a 75% duty cycle. Energy Dispersive X-Ray Spectroscopy (EDX) confirms the presence of Pt and Rh in the coating. XRD confirms that crystalline size was reduced from 75% duty cycle to the rest of the PC’s coatings and DC (Direct current). The incorporation of the Pt-Rh metal ions was verified by EDX analyses. The corrosion behaviour of the developed Pt-Rh alloy coatings was evaluated in 0.1 M Na2SO4 solution using potentiodynamic polarization and electrochemical impedance techniques. The coating developed at PC-75% duty cycle possesses the highest corrosion resistance. A photocatalytic degradation study of Pt-Rh coating was conducted for Methylene Blue (MB) dyes under UV light radiation. The dye removal efficiency of Pt-Rh coated samples was 97% after irradiation and PC 75% duty cycles showed an exceptional dye degradation percentage compare to the DC coating source. All photocatalytic behaviour was controlled by using a UV–Vis spectrophotometer