{0 0 1}-Facet-Exposed Ag₄V₂O₇ Nanoplates: Additive-Free Hydrothermal Synthesis and Enhanced Photocatalytic Activity

Abstract

The synthesis of silver pyrovanadate, Ag4V2O7, nanoplates with exposed {0 0 1}-facets by a facile, additive-free hydrothermal method was described in this paper. The photocatalytic activity of rhodamine B over Ag4V2O7 samples under solar light irradiation was also evaluated. By using an equimolar mixture of NH4VO3 and AgNO3 with the presence of a suitable amount of ammonia, Ag4V2O7 nanoplates were obtained readily and purely at temperatures from 100 to 140°C for 4 h. In particular, the c-axis orientation growth of Ag4V2O7 nanoplates occurred and increased monotonously with temperatures in the range of over 100 up to 140°C. Further increase in hydrothermal temperature up to 220°C, the Ag4V2O7 phase no longer existed and the β-AgVO3 phase was formed instead. The photocatalytic activity of the optimized Ag4V2O7 sample comprising {0 0 1}-facet-exposed nanoplates with the highest degree of orientation was significantly higher than that of the random-oriented sample. The effects of using ammonia as a complexing agent on the structure, microstructure, texture, exposed facet, and photocatalytic activity of Ag4V2O7 samples were also investigated for the first time.

Hybrid Cathodic/Anodic Electrosynthesis of Phase Pure Ag4V2O7 Thin Films

“…1 Hydrothermal synthesis has been predominantly used for preparing Ag 4 V 2 O 7 ; other methods for making powders of this material include solid state, hydrothermal, dynamic template, molten salt flux, and solution precipitation. [3][4][5][6][7][8][9][10][11][12][13][14][15][16] However, solar energy conversion schemes demand the active material to be compatible with scale up and deployment in large area modules. Thin films are eminently suited to this scenario and electrochemical deposition [17][18][19][20][21][22] delivers the target material in thin film form on conductive substrates.…”