Tuning the Anisotropic Facet of Lead Chromate Photocatalysts to Promote Spatial Charge Separation

Abstract

A crucial issue in artificial photosynthesis is how to modulate the behaviors of photogenerated charges of semiconductor photocatalysts. Here, using lead chromate (PbCrO4) as an example, we conducted the morphology tailoring from parallelepiped (p‐PbCrO4) to truncated decahedron (t‐PbCrO4) and elongated rhombic (r‐PbCrO4), resulting in exposed anisotropic facets. The spatial separation of photogenerated charges closely correlates to the anisotropic facets of crystals, which can only be realized for t‐PbCrO4 and r‐PbCrO4. The charge‐separation efficiencies exhibit a quasilinear relation with the surface photovoltage difference between anisotropic facets. The r‐PbCrO4 gives an apparent quantum efficiency of 6.5 % at 500 nm for photocatalytic water oxidation using Fe3+ ions as electron acceptors. Moreover, the oxidation reverse reaction from Fe2+ to Fe3+ ions was completely blocked with ∼100 % of Fe3+ conversion achieved on the anisotropic PbCrO4 crystals.

Construction of a P, N Co-Doped Nanocarbon-Embedded g-C3N4 Hollow Sphere Nanoreactor for the Efficient Photocatalytic Production of Hydrogen Peroxide

“…The g-C 3 N 4 -based sample-coated F-doped SnO 2 film (FTO) electrodes were synthesized on the basis of the literature (displayed in Supporting Information). , The photoelectrochemical measurement was conducted with sample-coated FTO as the working electrode, Pt sheet as the counter electrode, and the saturated calomel electrode (SCE) as the reference electrode. During visible light on or off, the result of photocurrent was acquired with a 0 V applied voltage in an O 2 -saturated Na 2 SO 4 solution (0.1 M).…”

Microwave-Assisted Synthesis of Bismuth Chromate Crystals for Photogenerated Charge Separation

“…Spatial charge separation between different facets of welldefined semiconductor crystals have been extensively studied to promote the charge separation properties of photocatalysts [15][16][17][18] . Fabricating semiconductor crystals with regular morphology and exposed facets is the key to realize spatial charge separation 19 .…”

Heterojunction construction by a coordination bond between metal–organic frameworks and CdIn2S4for improved photocatalytic performance

“…To solve these problems, a great many methods have been implemented to boost the photoreaction capability of semiconductors, such as metal doping, defect manufacturing, crystal facet control and heterojunction establishment. [12][13][14][15] All these strategies have been developed in recent years, and among them, heterojunction construction was proved to be an effective method for suppressing the electron-hole recombination during the photoreaction processes. Li et al proved experimentally that the construction of a heterojunction was conducive to the improvement of photocatalytic activity.…”