Urchinlike Ag/AgCl photocatalyst: Synthesis, characterization, and activity
•Novel and facile method of preparation leading to urchinlike Ag/AgCl nanoparticles.•An efficient photocatalyst that works under both UV and visible light.•Higher photocatalytic activity than TiO2 P25.
In this paper, an extraordinary Ag/AgCl compound with surprisingly photocatalytic activity was synthesized. The synthesis route was straight forward involving hydrolysis followed by ion-exchange reactions without using strong reducing and dispersing agents. The starting materials were TiCl4 and AgNO3. The latter was dissolved in ammonia solution prior to the addition of TiCl4. The morphology, composition, and phase structure of the as-prepared product were characterized by X-ray diffraction spectroscopy (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scanning electron microscopy (SEM), UV–visible diffused reflectance spectroscopy (DRS), and surface area analysis. The striking feature of this product was its near spherical shape aggregation of AgCl particles whose surface was fully covered with nanohairs. The lengths of the nanohairs were about 30 to 50 nm. The product was found to contain traces of metallic Ag mixed with the parent compound AgCl. The optical absorption spectrum of this product exhibited a strong absorption in the visible region because of the surface plasmon resonance (SPR) effect of Ag metal nanoparticles. Under either UV or visible light irradiation, urchinlike Ag/AgCl showed higher photocatalytic activity than commercial AgCl, simple AgCl, and commercial Degussa P25 TiO2. The possible photocatalytic mechanism is discussed based on the probable role of metallic Ag nanoparticles in enhancing the photocatalytic performance. The photocatalytic pathway was originated from the enhanced absorption for UV–visible light, electron–hole separation, and formation of Cl atoms in Ag/AgCl nanostructure.
Graphical abstract.Figure optionsDownload full-size imageDownload high-quality image (109 K)Download as PowerPoint slide
Journal: Applied Catalysis A: General - Volume 473, 5 March 2014, Pages 59–69