Light-induced spatial separation of charges toward different crystal facets of square-like WO₃

Abstract

Light-induced preferential migration of electrons and holes to the minor (200) and (020) facets and the dominant (002) facets of square-like WO, respectively, resulted in the square-like WO nanoplates with Pt loaded mainly on dominant (002) facets shows higher photocatalytic activity than that Pt loaded on the minor facets.

The synergetic effect of dual co-catalysts on the photocatalytic activity of square-like WO3with different exposed facets

“…The rectangular square-like WO 3 nanoplate with predominant facets of (002) and side facets of (020) and (200) based on our recent works. 23 It is known that Pt was used as the powerful reduction cocatalysts for high activity WO 3 . 5, 25 The choice of suitable oxidation cocatalysts is another important factor for photocatalytic water oxidation reaction.…”

“…13,[16][17][18][19][20][21][22] Our recent research works revealed that the square-like WO 3 nanoplates with Pt loaded mainly on dominant facets shows higher photocatalytic activity than that with Pt loaded on the edged facets due to light-induced charge separation between different facets of square-like WO 3. 23 However, the activity difference is not very big owe to that platinum particles were not effective oxidation reaction promoters for promoting O 2 evolution on the dominant (002) facets of square-like WO 3 . Therefore, the selective deposition of suitable cocatalysts on the needed facets of square-like WO 3, particularly loading suitable oxygengeneration promoters on the dominant (002) facets to stress the surface recombination of charge carriers and thus improve photocatalytic performance is feasible and urgent based on the charge separation between different facets.…”

“…13,16,22 Our recent research works reveal that light-induced preferential ow of photogenerated holes and electrons to the dominant (002) facets and edged facets of square-like WO 3 , on which oxidation and reduction occurs, respectively. 23 Here we proposed the reaction mechanism of visible-light-driven O 2 evolution over the square-like WO 3 loaded with Pt and PbO x dual cocatalysts as depicted in Fig. 12.…”

“…In general, light-induced spatial separation of the photogenerated electrons and holes toward the edged facets and the dominant crystal facets of square-like WO 3 nanoplates respectively, which results in hole-rich (002) major top facets and electron-rich (020) and (200) facets. 23 The oxidation reaction of water to O 2 evolution takes place on the hole-rich (002) major top facets, while the reduction reaction takes place on the electron-rich (020) and (200) facets. At the same time, PbO x cocatalysts loaded on the dominant facets act as oxidation sites for O 2 evolution to catalyze the four-electron water oxidation to produce O 2 , Pt loaded on the edged facets are to offer reduction sites for Ag + and catalyze the reduction reactions, namely the reduction of Ag + to Ag.…”

Tungsten Trioxide Nanostructures for Photoelectrochemical Water Splitting: Material Engineering and Charge Carrier Dynamic Manipulation

“…Apart from porous structure and 3D photonics crystal, the fabrication of unique structure with specific exposed crystal facets also provides a great platform to tune the PEC performance of WO 3 . The different facets exposed in photocatalyst remarkably influence their surface properties, such as surface energy, surface atomic coordination and surface electronic band structure, thus affecting the number of active sites, the absorption of reactive molecules and the redox ability of photogenerated carriers . Thus, tremendous efforts have been made to survey the most efficient facets of photoanodes, and the {001} and {111} facets in TiO 2 , {023} facets in SrTiO 3 , {010} facets in Cu 2 MoS 4 and so on have been reported to have high photocatalytic activity .…”