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

Abstract

Monophasic and hybrid nanostructures of KNbO 3 and α-Fe 2 O 3 have been prepared using a hydrothermal process for photoelectrocatalytic and photocatalytic applications. Powder X-ray diffraction studies showed the formation of KNbO 3 , α-Fe 2 O 3 , and KNbO 3 /α-Fe 2 O 3 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 2 /gm, respectively. Under simulated solar irradiation, the as-prepared heterostructure shows enhanced photoelectrocatalytic oxygen evolution reaction (OER) activity compared to pristine KNbO 3 and α-Fe 2 O 3 . Significant photocatalytic activity of as-synthesized KNbO 3 /α-Fe 2 O 3 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 3 , α-Fe 2 O 3 , and KNbO 3 /α-Fe 2 O 3 photocatalysts, respectively. The dielectric constant was found to be 250.2, 65.2, and 251.5 for KNbO 3 , α-Fe 2 O 3 , and KNbO 3 /α-Fe 2 O 3 heterostructure, respectively, at 50 °C and 500 kHz frequency.

Enhanced Visible-Light Absorption of Fe2O3 Covered by Activated Carbon for Multifunctional Purposes: Tuning the Structural, Electronic, Optical, and Magnetic Properties

“…The electronic, magnetic, structural, optical, and photocatalytic properties of Fe 2 O 3 can be tuned by adjusting the amount of carbon added, leading us to a promising multifunctional material for electromagnetic wave absorption/shielding and textile industry wastewater degradation. The novelty and photodegradation efficiency of this study compared with other references − can clearly be seen in Table . The effect of AC concentration shows the highest efficiency as 93.76% for 20% AC but takes 120 min, compared with that of 25% AC, which is 89.51% but takes only 90 min.…”

Advances in Z‐scheme semiconductor photocatalysts for the photoelectrochemical applications: A review

“…Furthermore, it is possible to combine properties, such as ferroelectricity or piezoelectricity, with the photocatalytic effect to improve photocatalytic activity. The perovskite photocatalysts can be classified into the following categories: titanates, SrTiO 3 112–118 and BaTiO 3 119–123 ; tantalates, LiTaO 3 , 124 NaTaO 3 125–132 and KTaO 3 133–137 ; niobates, LiNbO 3 , 138,139 NaNbO 3 140–147 and KNbO 3 148–153 ; vanadates, AgVO 3 154–162 ; and ferrites, LaFeO 3 , 164–169 BiFeO 3 170–176 and GaFeO 3 177 . These compounds show great potential for application in visible light‐driven photoreactions.…”

Silver-doped SnO2nanostructures for photocatalytic water splitting and catalytic nitrophenol reduction

“…Among these, doping in SnO 2 with foreign elements is considered to be an effective way to overcome the limitations of the low photocatalytic performance and to increase the yield. 48,51 Introducing Ag impurities can broaden the region of optical absorption for SnO 2 and offers a promising route toward photocatalytic applications. Moreover, the incorporation of silver into SnO 2 can allow the organic reactants to easily access the active catalytic sites, which results in enhanced catalytic efficiency.…”