ZnO–TiO2/rGO heterostructure for enhanced photodegradation of IC dye under natural solar light and role of rGO in surface hydroxylation

• Published in: Bulletin of materials science Vol. 46; no. 2; p. 83
• Main Authors: Kacem, Khaoula, Casanova-Chafer, Juan, Hamrouni, Abdessalem, Ameur, Sami, Güell, Frank, Nsib, Mohamed Faouzi, Llobet, Eduard
• Format: Journal Article
• Language: English
• Published: Bangalore Indian Academy of Sciences 20.04.2023; Springer Nature B.V
• Subjects: Catalytic activity; Chemistry and Materials Science; Dyes; Efficiency; Electromagnetic absorption; Engineering; Fourier transforms; Graphene; Heterojunctions; Heterostructures; Hydroxylation; Indigo; Light; Light irradiation; Materials Science; Microscopy; Nanocomposites; Nanomaterials; Photocatalysis; Photodegradation; Pollutants; Semiconductors; Spectrum analysis; Titanium dioxide; Zinc oxide; rGO; indigo carmine; photocatalysis; hydroxylation; ZnO–TiO; solar light
• ISSN: 0973-7669; 0250-4707; 0973-7669
• DOI: 10.1007/s12034-023-02913-7

To overcome the limitations of ZnO as a photocatalyst, the present work reports a ternary nanocomposite (ZnO–TiO 2 /rGO) with a high photocatalytic activity under direct natural solar light irradiation. Reduced graphene oxide (rGO) was obtained after bio-reduction of GO using pomegranate peels. Techniques of FE-SEM, TEM, XRD, FTIR, UV–Vis DRS, Raman and PL were used for characterization purpose. The ternary nanocomposite exhibited a high photocatalytic activity towards the degradation of indigo carmine dye, resulting in an efficiency of 92% within 150 min under sunlight illumination. Accordingly, the hybridization of ZnO with TiO 2 and rGO improves light absorption, promotes high separation of photogenerated charges, and solves the photocorrosion drawback of ZnO, leading to a better stability and reusability of the nanocomposite. Particularly, the prepared rGO allowed certain hydrophilicity and a better surface hydroxylation. In view of that, a comprehensive photocatalytic mechanism was proposed and discussed, referred to experiments showing the effect of holes and • OH scavengers. The findings revealed that the developed rGO hybridized with ZnO–TiO 2 heterojunction can be a promising candidate for removing environmental contaminations using natural solar light.