Selective photoredox activity on specific facet-dominated TiO2 mesocrystal superstructures incubated with directed nanocrystals

TiO2 mesocrystal with nitrogen and fluorine codoping during topochemical transformation: Efficient visible light induced photocatalyst with the codopants

“…The clear shrinks of the crystal lattice resulted from the doping are in good agreement with the movement of (1 0 1) diffraction peak toward to the higher angle range ( Fig. 2A inset) [21][22][23][24][25][26][27][28]. When the annealing temperatures increased to 500 • C, the void was formed to create the visual porous structures between the adjacent nanocrystals (Fig.…”

“…S6 and S7) [22]. On the other hand, NFT-600 with similar optical response to NFT-500 showed nearly half efficiency, which were resulted from the poor charge migration among the random nanoparticles because of the collapsed mesocrystal structure [23,35]. The negligible degradation was observed in the absence of NFT or visible light irradiation.…”

“…The samples were synthesized with some modifications according to the previous reports [22][23][24]. A precursor solution containing TiF 4 , H 2 O, NH 4 NO 3 , and NH 4 F (molar ratio = 1:503.4:4.9:2.4) was prepared, and were placed on a silicon wafer to form a thin layer.…”

Titanium Dioxide: From Engineering to Applications

“…Based on this mechanism, Majima et al performed extensive studies on tailoring TiO 2 mesocrystals with versatile structures and morphologies, as well as postmodifications to further improve their photocatalytic efficiency. For example, to investigate the anisotropic electron flow in different facets and to maximize their separation during the photocatalytic reaction, Zhang et al controllably synthesized a specific facet-dominated TiO 2 superstructure with NH 4 F as an orientation-directing agent [103]. Under UV light irradiation, mesocrystals with different facet ratios showed different reactivity orders in the photooxidation of 4-chlorophenol, i.e., {001} > {101} (by 1.7 times), and photoreduction, i.e., {101} > {001} (by 2-3 times).…”

Oxygen‐Deficient Dumbbell‐Shaped Anatase TiO2−x Mesocrystals with Nearly 100 % Exposed {101} Facets: Synthesis, Growth Mechanism, and Photocatalytic Performance

“…[34] Since then, rapidlyi ncreasing attention has been directed toward developing anatase mesocrystals with controlled morphologies as well as to investigating their photocatalytic properties. [44][45][46][47] Recently,i th as been documented that, because both the activity and the preference of photocatalytic reactions are sensitivet ot he surfacea tomic structure and electronic structure of TiO 2 ,t he development of TiO 2 photocatalysts with specifice xposed facets is becominga ne ffective way to enhancet heir photocatalytic performance. [44,[48][49][50] In particular,i th as been theoretically and experimentally revealed that the high-energy{ 001} facet, which was conventionally considered to be quite activea mong the low-indexf acets of anatase, actually exhibits lower reactivity than the thermodynamically stable {101} facet in both photooxidation reactions for COH radical generation and photoreduction reactions for hydrogen evolution.…”