The preparation and performance tuning of Co/Ni based catalysts for chlorine evolution reaction

Optical windows in the ocean suffer from bio-fouling inevitably, and electrochemical chlorination is considered to be a highly effective protective method. In this research, Co/Ni based chlorine evolution reaction (CER) catalysts were prepared using electrodeposition followed by calcination treatment. The results demonstrated that the stability and activity of the catalysts were influenced by the Co/Ni ratio of the electrolytes and calcination temperature, and the highest CER catalytic activity was achieved at a Co/Ni ratio of 1:1 and the calcination temperature of 350 °C. The calcinated catalyst (1:1, 350 °C) exhibited a CER selectivity of over 85% across a current density range of 1 to 20 mA/cm2. Additionally, it held excellent stability. The active chlorine produced via chronopotentiometry on this catalyst exhibited a nearly 100% bactericidal efficiency against both Pseudomonas aeruginosa and Staphylococcus aureus after a 20 min electrolysis period. Moreover, a designed electrochemical chlorination accessory integrated with the catalyst was applied successfully for the bio-fouling prevention of optical windows in seawater.