**4. Conclusions**

Cv is useful tool in oxidation of pollutants as phenols. The electropolymerization, by cyclic voltammetry, of phenols on Pt-surfaces is a notoriously complex process which depends on the phenols structure, the potential scan rate, the pH, the temperature and the phenols concentration. Comparing the voltammograms from the different monomer compound solutions, it was demonstrated that the polymer film resulting from both OCP and OHP oxidation leads to the higher surface deactivation degree. This is probably due to the higher adhering properties of POCP and POHP to Pt-surface.

The proposed mechanisms are well confirmed by different tools and agree with that mentioned in literatures.

The oxidation processes are partially controlled processes with stable diffusion coefficients at different scan rates.

The Obtained polymers are amorphous with higher thermal stability with smooth lamellar surface feature for POCP and a smooth feature with uniform thickness for POHP.

POCP modified Pt electrode could be used as one use pH sensor with good response and perfect Nernstian- slope especially at pH range 4-9 but its poor pH sensor at more acidic or basic solution and loose its response by time.

More work must be done to improve both response and stability of the sensor.

POHP is a perfect adsorbent to MB dye from aqueous solution and must be used in purification of waste water.
