Synthesis and photoactivity of anatase porous single crystals with different pore sizes

Porous Single‐Crystal‐Based Inorganic Semiconductor Photocatalysts for Energy Production and Environmental Remediation: Preparation, Modification, and Applications

“…In this way, the methods can be grouped according to the reaction type as solvothermal (hydrothermal),2,16,17 sol–gel synthesis,18 chemical vapor deposition (CVD),19 molten‐salt reaction,20,21 electrochemical22 and ion‐exchange methods 23,24. Moreover, based on the strategy to generate porosity, preparation procedures for PSCs can also be divided into hard‐templating,2,7,16,17,23,25–27 soft‐templating,28–35 and template‐free 22,36–41. For the purpose of this review, PSCs preparation procedures have been classified according to the manner employed to create porosity, so that the amazing range and variety of PSCs can be remarked.…”

“…Currently, the PSCs materials that have been reported to be prepared by this method include TiO 2, 2,4,17,26,27,47–50 ZnO,25 BiVO 4 ,16 SnO 2 ,51,52 CeO 2 ,4 and Fe 2 O 3 ,15 among others. The crystals produced by this procedure can display regular and irregular crystalline shapes, depending on whether or not there is a preferential growth in the crystal of some specific facets.…”

“…Close packing of silica spheres contacting each other assists the generation of coherent holes inside the crystals by inverse replica. Subsequent etching of the silica spheres by NaOH solution renders the TiO 2 PSC26 ( Figure ).…”

“…Different Ti sources employed in the seeding‐template strategy to fabricate anatase TiO 2 PSCs are those that have been extensively used for the synthesis of anatase single crystals with exposed {001} facets 3,55. Besides TiF 4 ,2,26,27 tetrabutyl orthotitanate (TBOT) is another Ti source that has been widely used in PSC synthesis 47–50. Zheng et al have reported that preseeding is necessary when using silica template and TBOT as the Ti precursor.…”

Synthesis and hydrogenation of anatase TiO2 microspheres composed of porous single crystals for significantly improved photocatalytic activity

“…Desorption curves of samples exhibit the hysteresis loop of type E which can be attributed to the inkwell-type pore structure formed by the close-packed template spheres inside anatase crystal. 19 The…”