Phase stabilization and exposed {100} facet growth of α-Ag3VO4 photocatalyst: A low-temperature, template-free hydrothermal synthesis approach

• Published in: Materials science & engineering. B, Solid-state materials for advanced technology Solid-state materials for advanced technology, 2022-04, Vol.278, p.115616, Article 115616
• Main Authors: Duc Van, Nguyen, Thi Anh Thu, Do, Thi Hong Le, Ngo, Tuan Anh, Doan
• Format: Article
• Language: English
• Subjects: Ammonia; Catalytic activity; Crystallography; Dyes; Exposure; Hydrothermal synthesis; Light irradiation; Low temperature; Methyl orange; Microcrystals; Phase stabilization; Photocatalysis; Photodegradation; Silver nitrate; Stabilization; Template-free; α-Ag3VO4
• ISSN: 0921-5107; 1873-4944
• DOI: 10.1016/j.mseb.2022.115616

•Pure α-Ag3VO4 was synthesized hydrothermally from AgNO3, NH4VO3 and ammonia.•α-Ag3VO4 phase was stabilized with temperatures ranged from 40 to 180 °C.•a- oriented, {100}-faceted α-Ag3VO4 microcrystals were template-free resulted.•{100}-facets exposed α-Ag3VO4 are much higher photoactive than the bulk sample.•Ammonia played both complexing/pH adjusting roles in stabilizing faceted α-Ag3VO4. The low-temperature phase stabilization, exposed {100} facet growth and solar light photocatalytic activity of α-Ag3VO4 microcrystals synthesized by a template-free hydrothermal procedure from AgNO3, NH4VO3 and ammonia were reported. By simply selecting a stoichiometric AgNO3/NH4VO3 molar ratio and a suitable amount of ammonia, pure α-Ag3VO4 powders were received readily at temperature as low as 100 °C while the competitive phase formation of the less photoactive Ag4V2O7 was inhibited completely. Especially, by increasing hydrothermal temperature from 100 to 160 °C, the crystallographic orientation growth of α-Ag3VO4 microcrystals along a-axis occurred and gradually diminished. For optimized sample, α-Ag3VO4 microcrystals were enclosed by exposed {100} facets, providing a significant enhancement in photocatalytic activity for methyl orange photodegradation under simulated solar light irradiation with respect to that of the random-oriented bulk sample. The role of ammonia on the low-temperature phase stabilization and exposed {100} facet growth of Ag3VO4 was also discussed.