Polypyrrole-TiO2 composite for removal of 4-chlorophenol and diclofenac.

In this work, we successfully synthesized TiO 2 -polypyrrole (PPy) composite material via polymerization method using the sulfuric acid (H 2 SO 4) as an oxidizing agent. Different characterization techniques, including electrostatic force microscopy, confirmed that TiO 2 was intimately attached on PPy. The photocatalytic activity of PPy-TiO 2 composite was studied experimentally for the conversion of diclofenac (DCF)– one of the most frequently detected pharmaceutical compounds in the aquatic environment – and 4-chlorophenol (4-CP) - largely used in the bleaching of cellulose pulp in the paper industry, as herbicide and pesticide - under simulated solar light irradiation at environmental conditions. This is the first time that a composite PPy-TiO 2 was used as photocatalyst for the conversion of 4-CP. Results showed that the PPy-TiO 2 was able to convert more than 90% of DCF and 40% of 4-CP in just 60 min, showing stability and efficiency over five consecutive cycles of reuse for both pollutants. The produced PPy-TiO 2 showed higher photocatalytic efficiency compared to that of TiO 2 , thus proving itself to be a promising photocatalyst. Unlabelled Image • Hybridizing of PPy with TiO 2 results in narrowing of band gap. • The electrical properties were evaluated by AFM and EFM. • Characterization results provided evidence of an interfacial interaction via Ti-O-C. • PPy-TiO 2 is effective in the conversion of DCF and 4-CP. • PPy may act as electron acceptor and self-photo-sensitizer. [ABSTRACT FROM AUTHOR]