Development of Cuboidal KNbO3@α-Fe2O3 Hybrid Nanostructures for Improved Photocatalytic and Photoelectrocatalytic Applications

Umar Farooq; Preeti Chaudhary; Pravin P Ingole; Abul Kalam; Tokeer Ahmad

doi:10.1021/acsomega.0c02646

Development of Cuboidal KNbO₃@α-Fe₂O₃ Hybrid Nanostructures for Improved Photocatalytic and Photoelectrocatalytic Applications

ACS Omega. 2020 Aug 9;5(32):20491-20505. doi: 10.1021/acsomega.0c02646. eCollection 2020 Aug 18.

Authors

Umar Farooq¹, Preeti Chaudhary², Pravin P Ingole², Abul Kalam³, Tokeer Ahmad¹

Affiliations

¹ Nanochemistry Laboratory, Department of Chemistry, Jamia Millia Islamia, New Delhi 110025, India.
² Department of Chemistry, Indian Institute of Technology, Hauz Khas, New Delhi 110016, India.
³ Department of Chemistry, College of Science, King Khalid University, Abha 61413, Saudi Arabia.

Abstract

Monophasic and hybrid nanostructures of KNbO₃ and α-Fe₂O₃ have been prepared using a hydrothermal process for photoelectrocatalytic and photocatalytic applications. Powder X-ray diffraction studies showed the formation of KNbO₃, α-Fe₂O₃, and KNbO₃/α-Fe₂O₃ with average grain sizes of 18.3, 11.5, and 26.1 nm and Brunauer-Emmett-Teller (BET) specific surface areas of 4, 100, and 20 m²/gm, respectively. Under simulated solar irradiation, the as-prepared heterostructure shows enhanced photoelectrocatalytic oxygen evolution reaction (OER) activity compared to pristine KNbO₃ and α-Fe₂O₃. Significant photocatalytic activity of as-synthesized KNbO₃/α-Fe₂O₃ heterostructure photocatalyst was obtained for removal of methylene blue organic dye under visible light, and the percentage activity was found to be 11, 49, and 89% for KNbO₃, α-Fe₂O₃, and KNbO₃/α-Fe₂O₃ photocatalysts, respectively. The dielectric constant was found to be 250.2, 65.2, and 251.5 for KNbO₃, α-Fe₂O₃, and KNbO₃/α-Fe₂O₃ heterostructure, respectively, at 50 °C and 500 kHz frequency.