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A novel rod-shape sonocatalyst Sr(OH)2·8H2O was prepared by a facile precipitation method, and characterized by X-ray powder diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy and UV-vis absorption spectroscopy. Comparative sonocatalytic degradation experiments were carried out in different conditions under ultrasonic irradiation by using rhodamine B (RhB) as the model substrate, indicating that Sr(OH)2·8H2O was highly sonocatalytic. Total organic carbon experiment demonstrated Sr(OH)2·8H2O with mass mineralization of organic carbon. The effects of catalyst amount, initial RhB concentration and ultrasonic energy of degradation were investigated, and the sonocatalyst could be reused 5 times without significant loss of activity. Furthermore, the potent degrading capability was ascribed to ultrasonic cavitation producing flash light/energy which generated radicals (e.g., OH) with high oxidation activity.

Bi 3+ -doped Ag/AgCl photocatalytic materials were synthesized using a simple coprecipitation approach. Powder X-ray diffraction analysis revealed that Bi 3+ was inserted into the crystal lattice of AgCl to partially replace Ag + , resulting in the contraction of AgCl lattice. Ultraviolet−visible absorption tests showed that the dopant Bi 3+ slightly widened the band gap of AgCl as it raised the conduction level. X-ray photoelectron spectroscopy revealed the strong interaction between Bi 3+ , Ag + , and Cl − , and also showed the presence of abundant Bi 3+ on the surface of AgCl particles. Methyl orange (MO) photodegradation experiment showed the photocatalytic activity of the Bi 3+ -doped Ag/AgCl was significantly dependent on the amount of doped Bi 3+ . The Bi 3+ -doped Ag/AgCl (2 wt %) reached the highest activity of 91% after 8 min, while the pure Ag/AgCl degraded only 32% of MO. The degradation rate constant of Bi 3+ -doped Ag/AgCl was 3.75 times higher than that of pure Ag/AgCl. Electron spin resonance showed that • OH was the main active species during the oxidation of MO using the Bi 3+ -doped Ag/AgCl. During the photodegradation of MO, the photocatalytic activity of Ag/AgCl was first enhanced and then weakened along with the increased amount of Bi 3+ . These changes were theoretically attributed to the formation of chloride dangling bonds and vacancies induced by the dopant Bi 3+ . The chloride dangling bonds from Bi 3+ also enhanced the photocatalytic activity of Ag/AgCl.

V 5+ -doped Ag/AgCl photocatalysts were prepared via the ion exchange method. The catalysts were characterized using X-ray diffractometry, transmission electron microscopy, and energy-dispersive X-ray, X-ray photoelectron, Fourier transform infrared and ultraviolet-visible spectroscopies. The V 5+doped Ag/AgCl photocatalysts show much higher photocatalytic activities than Ag/AgCl under visible light irradiation for methyl orange (MO) decomposition.Especially, the 2.0 wt% V 5+ -doped Ag/AgCl photocatalyst shows the highest photocatalytic activity and also high stability after five cycles. The MO degradation rate during each cycle is almost maintained at 97%. Electron spin resonance spectroscopy and radical trapping experiments reveal that holes play an important role in the photocatalytic process. KEYWORDS enhanced mechanism, photocatalyst, V 5+ -doped Ag/AgCl

A novel sonocatalyst CdS was prepared by a facile precipitation method, and characterized by X-ray powder diffraction, transmission electron microscopy, UV-vis absorption spectroscopy, and photoluminescence spectroscopy. Comparative sonocatalytic degradation experiments were carried out in different conditions under ultrasonic irradiation and with rhodamine B (RhB) used as the model substrate. Results indicate that CdS is a highly active sonocatalyst. The efficiency of RhB sonodegradation in aqueous solutions within 4 h is up to 70% after the addition of CdS. Abundant •OH during the RhB sonodegradation was detected, which may be responsible for the high sonodegradation rate over CdS under ultrasonic radiation.