Facet Effect of Single-Crystalline Ag3PO4 Sub-microcrystals on Photocatalytic Properties

International Center for Materials Nanoarchitectonics (MANA) and Photocatalytic Materials Center, National Institute for Materials Science (NIMS), 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan.
Journal of the American Chemical Society (Impact Factor: 11.44). 05/2011; 133(17):6490-2. DOI: 10.1021/ja2002132
Source: PubMed

ABSTRACT We recently reported that Ag(3)PO(4) exhibits excellent photooxidative capabilities for O(2) evolution from water and organic dye decomposition under visible-light irradiation. However, very little is known about the shape and facet effects of Ag(3)PO(4) crystals on their photocatalytic properties. Herein we have developed a facile and general route for high-yield fabrication of single-crystalline Ag(3)PO(4) rhombic dodecahedrons with only {110} facets exposed and cubes bounded entirely by {100} facets. Moreover, studies of their photocatalytic performance have indicated that rhombic dodecahedrons exhibit much higher activities than cubes for the degradation of organic contaminants, which may be primarily ascribed to the higher surface energy of {110} facets (1.31 J/m(2)) than of {100} facets (1.12 J/m(2)).

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Available from: Naoto Umezawa, Aug 01, 2015
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    • "Another approach is to develop a new visible-light-driven photocatalyst with high activity [8] [9] [10] [11] [12]. Till to now, a lot of novel photocatalysts, including CaBi 2 O 4 [8], Ag 3 PO 4 [10], g-C 3 N 4 [11] and Bi 2 WO 6 [12], has been reported. Among them, g-C 3 N 4 has attracted a great deal of interests due to its good photoactivity, moderate band gap, and low cost. "
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    ABSTRACT: This research was designed for the first time to investigate the activities of CdMoO4/g-C3N4 heterojunction in photocatalytic degradation of rhodamine B (RhB) and converting CO2 to fuels. The composite was synthesized via a simple mixing-calcination method and characterized by various techniques including Brunauer-Emmett-Teller method (BET), X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, UV-vis diffuse reflectance spectroscopy, photoluminescence spectroscopy, and electrochemical method. The results showed that the introduction of CdMoO4 to g-C3N4 exerted little effect on the property of light absorption, but resulted in an increase in the BET surface area, which was beneficial for the adsorption of RhB. More importantly, formation of a hetero-junction structure between CdMoO4 and g-C3N4 significantly promoted the separation of electron-hole pairs and ultimately enhanced the photocatalytic activity. The optimal CdMoO4/g-C3N4 composite could degrade RhB 6.5 times faster than pure g-C3N4 under visible light irradiation. Meanwhile, the composite showed a CO2 conversion rate of 25.8μmolh(-1)gcat(-1), which was 4.8 and 8.1 times higher than those of g-C3N4 and P25, respectively, under simulated sunlight irradiation. This work might represent an important step in simultaneous environmental protection and energy production by g-C3N4 based materials. Copyright © 2015 Elsevier B.V. All rights reserved.
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    • "Although various novel visible-light-responsive materials, such as CaBi 2 O 4 , BiVO 4 , Ag 3 PO 4 , etc. [4] [5] [6] [7] [8], have been reported, only a few of these materials have attracted much interest. Graphitic carbon nitride (g-C 3 N 4 ) is an outstanding photocatalyst because of its high reducibility and visible-light adsorption [8]. "
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    • "In 2010, an orthophosphate semiconductor with excellent photooxidation properties under visible-light irradiation was found by Yi et al. [29], and the excellent photocatalytic performance of Ag 3 PO 4 was revealed to be attributed to the highly dispersive band structure of the conduction-band minimum resulting from Ag seAg s hybridization without localized d states, according to the comprehensive study using density-functional-theory-based calculations [30]. Also, single-crystalline Ag 3 PO 4 rhombic dodecahedrons with only {110} facets exposed and cubes bounded entirely by {100} facets [31], tetrahedron nanocrystals exposed entirely with {111} facets [32], and uniform hierarchical Ag 3 PO 4 porous microcubes [33], were synthesized successfully, with improved photocatalytic activity in decomposition of organic pollutants. Some other complex based on Ag 3 PO 4 photocatalyst such as AgX/Ag 3 PO 4 (X ¼ Cl, Br, I) coreeshell heterostructures with an unusual rhombic dodecahedral mor phology [34], CQDs/Ag 3 PO 4 complex [35], Ag 3 PO 4 /TiO 2 with improved stability [36], were also found to perform better photocatalytic activity. "
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