Uniform cubic Ag@AgCl plasmonic photocatalyst was synthesized by a facile green route in the absence of organic solvent, in which a controllable double-jet precipitation technique was employed to fabricate homogeneous cubic AgCl grains and a photoreduction process was used to produce Ag nanoparticles (NPs) on the surface of AgCl. During the double-jet precipitation process, the presence of gelatin and Cl– ions at low concentration was necessary for the formation of cubic AgCl grains. Atomic force microscopy (AFM) was used to probe the morphological structure of Ag@AgCl grains for the first time, which showed that Ag NPs are anchored on the surface of AgCl grains like up-and-down mounds. Further characterization of the photocatalyst was also done by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and UV–visible diffuse reflectance spectroscopy (DRS). The as-prepared Ag@AgCl plasmonic photocatalyst exhibited excellent photocatalytic efficiency for the degradation of the azo dye acid orange 7 (AO7), phenol, and 2,4-dichlorophenol (2,4-DCP). The photocatalytic mechanism was studied by radical-trapping experiments and the electron spin resonance (ESR) technique with 5,5-dimethyl-1-pyrroline N-oxide (DMPO), and the results indicated that •O2 – and Cl0 are responsible for the rapid degradation of organic pollutants under visible-light irradiation.

A facile hydrothermal route employing H2O2 as structure-directing agent was explored to fabricate anatase microflowers with dominant {101} facets and anatase microspheres with exposed {001} facets. The influence of H2O2 concentration on crystal structure, morphology, and facet composition of TiO2 was investigated in detail. H2O2 plays a crucial role in determining the crystal structure, morphology, and exposed facets of TiO2. The presence of H2O2 favors the formation of anatase phase. When the concentration of H2O2 was in the range 0.7–3.3 M, anatase microflowers with dominant {101} facets were produced. In contrast, when the concentration of H2O2 was higher than 6.6 M, anatase microspheres with exposed {001} facets were formed. A mechanism was proposed to account for the influence of H2O2 on crystal structure and morphology of TiO2. Photocatalytic degradations of rhodamine B and 2,4-dichlorophenol indicated that anatase microspheres with exposed {001} facets showed much higher photocatalytic activity than anatase microflowers with dominant {101} facets.

Anatase TiO 2 microcrystals containing ∼15% highly reactive {110} facets were successfully synthesized by a one-step hydrothermal method, in which H 2 O 2 , HF, and Cl − ions showed a synergistic effect on the formation of {110} facets. Benefiting from the surface heterojunction structure, TiO 2 microcrystals with {110} facets showed an enhanced photocatalytic activity for dye degradation.