Synergistic Role of B and F Dopants in Promoting the Photocatalytic Activity of Rutile TiO₂

Abstract

Herein, we synthesize B,F-doped TiO2 powders and elucidate\ud for the first time the nature of active centers responsible for\ud the catalytic activity of rutile TiO2, even when a very low surface area is present. In particular, we used electron paramagnetic resonance (EPR) for a thorough characterization of catalytically\ud active sites. Since during TiO2 synthesis the presence\ud of B or F dopants induces the low-temperature formation of a\ud mixture of anatase, rutile, brookite polymorphs, the attention\ud was focused on high-temperature-treated materials, containing\ud the pure rutile phase and possessing a negligible surface area.\ud This work demonstrates that a suitable synthetic design can\ud transform even a “stone” with insignificant surface area into a\ud very efficient photocatalyst. Specifically, herein we show the\ud existence of a critical synergic interaction between B and F codopants\ud in rutile titania that weakly enhances Vis-light absorption\ud but, notably, generates active photocatalytic sites. We\ud show that concomitant surface/second layer B and surface F\ud are needed to get a significant MO degradation. The present\ud investigation reveals that dopant distribution in the active material\ud is of key importance and must be carefully considered in\ud tailoring material properties. The simplicity of our preparation\ud synthesis is a significant advantage in view of large-scale applications

MOCVD of TiO2 thin films from a modified titanium alkoxide precursor

“…displays the Ti2p and N1s regions. The Ti2p 3/2 peak was always centered at BE = 458.6 eV, in line with literature reports for octahedral Ti(IV) in TiO 2 .…”

Photocatalytic Properties of Co3O4-Coated TiO2 Powders Prepared by Plasma-Enhanced Atomic Layer Deposition

“…The strong peak at 529.9 eV can be assigned to the O–Ti bond. The weak peak with higher binding energy at 532.2 eV is attributed to the absorbed OH species on the sample surfaces [44]. The O1s peak of Co 3 O 4 should locate at ~ 529.8 eV [43], which is difficult to be distinguished from the O–Ti bond.…”

Photocatalytic degradation of pentachlorophenol by visible light Ν–F–TiO2 in the presence of oxalate ions: optimization, modeling, and scavenging studies

“…In earlier studies, PCP degradation has been investigated by means of UVand natural solar irradiation over TiO 2 suspensions (Minero et al 1993;Mills and Hoffmann 1993;Jardim et al 1997). However, some drawbacks of TiO 2 such as recombination of electronhole pairs leading to low quantum yield and wide band gap of TiO 2 which lead to poor light harvesting ability limit significantly its practical application (Gombac et al 2007;Fittipaldi et al 2011;Giannakas et al 2013;Antonopoulou et al 2014).…”

“…In order to improve the photocatalytic activity, doping of TiO 2 by anionic species, such as N, B, S, I, F, or with codoping such as N-I, N-S, and N-F is receiving increasing attention (Gombac et al 2007;Fittipaldi et al 2011;Giannakas et al 2013). Enhanced catalytic activity for the degradation of PCP under visible light was achieved by N-F-doped TiO 2 Govindan et al 2013).…”