Chlorination of water is the cheapest and usually the last step in water treatment process, which disinfects the water. With the rapid growth of population need for clean water rises even more intensely. The pure chlorine itself is very powerful oxidizing agent, as is toxic to humans, but chlorine also reacts with organic matter leftover in water, forming dangerous and even carcinogenic byproducts [1]. Metal foams are quite novel, low density, highly porous metallic structures, that can be manufactured in plethora of ways [2]. However electrochemically using dynamic hydrogen bubble template one can deposit metal foams of desired composition. Whilst controlling deposition condition and constitution of solution, the porosity and surface area of metal foams can be varied. Cobalt foams have been formed on copper substrate with nickel seed layer (10nm thick) using galvanostatic and pulse deposition techniques. Depositions were performed in solutions containing 0.2M CoCl2 and 2M NH4Cl or 0.2M CoSO4 and 1M (NH4)2SO4. Effects of isopropyl alcohol were investigated on cobalt foams surface area. Foams have been investigated using SEM with EDS module, XRD spectroscopy, EIS and other electrochemical techniques. Cobalt foams surface area was estimated using Double Layer Capacitance values obtained from EIS data. In order to detect concentrations of free chlorine in water, cobalt foams were modified using cyclic voltammetry technique in solution containing K4[Fe(CN)6] by forming cobalt hexacyanoferrate on the surface of the foam. Free chlorine in water was detected using chronoamperometric measurements in 0.05M acetate buffer with 0.1M KNO3 background electrolyte. The response was around 45 μA per 1 mg/l of free chlorine, which is much higher than the one reported in literature.