Abstract
This work examines the potential of conducting polymers with transition metal oxides as a photocatalyst in environmental remediation. A visible light-responsive ternary composite of PANI-rGO-MnO2 was synthesized and evaluated its photocatalytic activity of a cationic dye (i.e., methylene blue, MB) in an aqueous solution. The surface morphologies and structural properties of the synthesized PANI, PANI-rGO, and PANI-rGO-MnO2 were examined. In the case of ternary composite, the successful growth/incorporation of MnO2 nanoparticles into the PANI-rGO composite was demonstrated. Furthermore, the lowered optical band gap of the ternary composite illustrates the extended light absorption range for the PANI-rGO-MnO2 photocatalyst. The photocatalytic experiments show that the PANI-rGO-MnO2 ternary composite exhibited significantly enhanced catalytic and photocatalytic activity for 90% degradation of methylene blue (MB) under visible light irradiation within 2 h. It could be attributed to synergistic effects by (i) facilitating the electron transfer from excited by reduced graphene oxide from the excited dye to PANI-MnO2 and (ii) reducing the recombination of photogenerated electron/hole pairs originating from the heterostructure of the ternary composite. The present work provides new insights into the synthesis of conducting polymer PANI, PANI-rGO, and the ternary composite of PANI-rGO-MnO2 as an efficient photocatalyst, and the developed composites would have potential applications in environmental remediation related fields.
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•PANI-rGO binary composite was prepared by polymerization of aniline with rGO.•PANI-rGO based ternary composite was synthesized by incorporating with MnO2.•Photocatalytic activity of the composites was tested for methylene blue dye degradation.•90% degradation of MB by PANI-rGO-MnO2 composite was achieved within 2 hr at pH 7.•PANI-rGO-MnO2 was an efficient photocatalyst under visible light irradiation.