Electrochemical Sensing and Photoelectrodegradation of Pentachlorophenol using Co‐, Mn‐ and Zn‐Porphyrins

In this work, we present Zn, CoII, and MnIII metalated meso‐tetra‐[4‐(methylthio) phenyl] porphyrin ([Zn(TMtPP)], [CoII(TMtPP], and [MnIII(TMtPP)Cl]) as electrocatalysts and photoelectrocatalysts for electrochemical detection and photoelectrocatalytic degradation of pentachlorophenol (PCP). The complexes were characterized using UV‐visible spectroscopy, mass spectroscopy, and elemental analysis. Proton nuclear magnetic resonance (1H NMR) studies were only conducted for the Zn derivative. The electrochemical detection of PCP was carried out using cyclic voltammetry and chronoamperometry. [CoII(TMtPP)] showed better detection limit. For photoelectrocatalytic (PEC) degradation studies of PCP, linear sweep voltammetry and UV‐visible spectra were employed. [Zn(TMtPP)] showed better removal efficiency. The main species responsible for the PEC degradation were found to be superoxide radicals (⋅O2) and electron holes (h+). Photoelectrocatalysis: Metal porphyrins are used as catalysts in electrochemical sensing and photoelectrodegradation of pentachlorophenol (PCP) with good catalytic activity in both applications. Electroactive metal based porphyrin gave better sensing whereas photoactive metal based porphyrin resulted in better degradation of PCP.