Development of Cuboidal KNbO@α-FeO Hybrid Nanostructures for Improved Photocatalytic and Photoelectrocatalytic Applications.

Monophasic and hybrid nanostructures of KNbO and α-FeO have been prepared using a hydrothermal process for photoelectrocatalytic and photocatalytic applications. Powder X-ray diffraction studies showed the formation of KNbO, α-FeO, and KNbO/α-FeO 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 m/gm, respectively. Under simulated solar irradiation, the as-prepared heterostructure shows enhanced photoelectrocatalytic oxygen evolution reaction (OER) activity compared to pristine KNbO and α-FeO. Significant photocatalytic activity of as-synthesized KNbO/α-FeO 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 KNbO, α-FeO, and KNbO/α-FeO photocatalysts, respectively. The dielectric constant was found to be 250.2, 65.2, and 251.5 for KNbO, α-FeO, and KNbO/α-FeO heterostructure, respectively, at 50 °C and 500 kHz frequency.