Photoelectrocatalytic degradation of partially hydrolyzed polyacrylamide using a novel particle electrode

Abstract

Tetrapyrazinoporphyrazines and their metal derivatives (TPyzPzs) are the most widely studied class of phthalocyanines azaanalogues. The present study describes a two-step synthesis for the cobalt complex of tetra-2,3-(5,6-di-tert-butyl-pyrazino) porphyrazine (tBu-TPyzPzCo) starting from pivalil, 2,3-diaminomaleonitrile, metal salts, and urea. The product was ultrasonically impregnated onto carbon black (CB), wherein particle electrodes (tBu-TpyzPzCo/CB) were employed for the degradation of partially hydrolyzed polyacrylamide (HPAM) in a three-dimensional electrocatalytic system under xenon lamp. HPAM exhibited more efficient degradation in the presence of a supporting catalyst using the photoelectrocatalytic process than by photocatalytic or electrocatalytic oxidation or even the sum of the two in saline water. The effects of HPAM degradation on various parameters in the photoelectrocatalytic reactor, such as the catalyst dosage, following the application of a cell voltage and an electrolyte were investigated in detail. Hydroxyl radicals and superoxide radicals were determined as the main active species in the reaction. The reaction mechanism was also discussed.