The
standard method of COD analysis is a time-consuming procedure; unable of be online monitored; requires expensive
(Ag2SO4) and toxic (HgSO4) reagents; and generate hazardous waste which requires disposal [3, 4]. Various
analytical techniques based on either electrocatalytic [5, 6] or photocatalytic [7–10] oxidation principles have been
made to solve these problems [3-11].