Enhanced visible light absorption and photocatalytic activity of [KNbO 3 ] 1−x [BaNi 0.5 Nb 0.5 O 3−δ ] x synthesized by sol–gel based Pechini method

• Published in: RSC advances 2016, Vol.6 (85), p.82409-82416
• Main Authors: Wu, Ping, Wang, Guoming, Chen, Ruizhi, Guo, Yixin, Ma, Xueming, Jiang, Dongmei
• Format: Article
• Language: English
• Subjects: Catalytic activity; Displays; Light absorption; Photocatalysis; Potassium niobates; Sol gel process; Titanium dioxide; X-rays
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/C6RA15288K

Ba, Ni co-modified KNbO 3 nanocrystals (KBNNO) were synthesized by sol–gel based Pechini method. X-ray diffraction and Raman measurements reveals the phase transformation of KBNNO from orthorhombic to cubic phase with increasing doping ratio x . Particle sizes of KBNNO nanocrystals were measured to range from 50 nm to 200 nm by scanning electron microscopy. X-ray photoelectron spectroscopy and electron dispersive X-ray elemental analysis reveal the elemental composition of KBNNO samples. Ultraviolet-visible-near infrared optical absorption spectra of KBNNO show enhanced visible light absorption compared with pure KNbO 3 synthesized under the same conditions. Photocatalytic activity evaluation displays an enhanced visible light photocatalytic activity of KBNNO in degrading methylene blue in comparison with KNbO 3 and P25 TiO 2 . Notably, KBNNO with x = 0.2 displays the greatest photoreactivity compared with KNbO 3 and P25 TiO 2 . The mechanism responsible for the enhancement of visible light absorption by Ni 2+ in KBNNO was discussed, highlighting the crucial role that Ni 2+ ions have played in the sub-energy levels of KBNNO.