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Au nanoparticles (Au NPs) were deposited onto BiOCl 1−x Br x nanosheets by using a facile ultrasonic treatment. The obtained Au-BiOCl 1−x Br x composites exhibit excellent photocatalytic property in the reaction of decomposing phenol aqueous solution under simulated solar light irradiation. There is a positive relationship exists in the surface plasmon resonance (SPR) of Au NPs and enhanced activities, which is contributed to the separation of photo-induced electrons and holes as well as facilitate the absorption of visible light. In addition, the tunable energy band structure might be beneficial to enhance the photocatalytic activities of Au-BiOCl 1−x Br x composites for optimizing the bandgap. And the OH and h + species were the main active species in photocatalytic reactions. In this paper, the Au-BiOCl 1−x Br x photocatalysts were demonstrated to be a promising material for practical applications in the purification of organic pollutants.

A series of heterojunction Ag 2 O/AgI photocatalysts with different Ag 2 O contents were successfully prepared though a facile two-step precipitation process at room temperature. The as-synthesized samples were measured in detail by XRD, EDS, XPS, SEM and DRS. The results showed that pherical Ag 2 O nanoparticles with diameter about 100–300 nm were uniformly distributed on the surface of AgI leading to the formation of Ag 2 O/AgI heterojunction. The photocatalytic activities of the obtained photocatalysts were evaluated by photocatalytic degradation of Rhodamine B (RhB) under visible light irradiation. The Ag 2 O/AgI with molar ratio of 1:1 showed the highest photocatalytic activities compared to the pure Ag 2 O and AgI with almost all RhB decomposed in 25 min. During photocatalytic process the visible light induced photogenerated electrons can be captured by Ag + ions on the surface lattice of heterojunction to form plasmonic Ag nanoparticles, which may promote the interfacial charge transfer. The enhanced photocatalytic activity was then largely attributed to the synergetic effects of heterojunction Ag 2 O/AgI/Ag and the efficient separation of photogenerated electron–hole pairs. This research may provide a novel Ag 2 O/AgI heterojunction with assistant of plasmonic Ag NPs to generate efficient, stable, and recyclable visible-light-driven plasmonic photocatalysts. The photocatalytic reaction kinetics and possible photocatalytic mechanism for this highly efficient photocatalysts were also proposed.

A novel heterojunction photocatalyst CdWO 4 /BiOBr was fabricated combining nano-rod CdWO 4 with flake-like BiOBr through a hydrothermal and subsequently chemical precipitation method. The samples were characterized by transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), Energy dispersive X-ray detector (EDS), X-ray diffraction (XRD) and UV–vis spectrophotometer. Moreover the photocatalytic activities were evaluated by decomposing dye molecule RhB under visible light irradiation. The results showed that high photocatalytic performance can be achieved on the heterojunction photocatalysts with the 15% CdWO 4 /BiOBr composite displaying highest activity. The results of the study concluded that it was the introduction of BiOBr into the catalyst that mainly enhanced the activity of the photocatalyst by promoting the separation of electron–hole group on the interface of BiOBr and CdWO 4 .

In this study, BiOCl doped with different contents of zinc were successfully prepared via a facile ethylene glycol (EG)-assisted solvothermal process at 160 °C for 12 h. The as-synthesized samples were characterized in details by X-ray powder diffraction (XRD), energy dispersive X-ray analysis (EDS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), UV–vis diffuse reflectance spectra (UV–vis DRS) and Brunauer Emmet Teller (BET) measurement. The photocatalytic performances were evaluated by the photocatalytic degradation of Rhodamine B (RhB) under visible light irradiation. The results showed that Zn doping did not change the morphologies and particle sizes of BiOCl. However, it had an obvious effect on the photocurrent and BET surface area of BiOCl and accordingly the photocatalytic performance of BiOCl was greatly improved. The Zn-doped BiOCl with RZn = 0.07 showed the highest photocatalytic activities with almost all of the RhB decomposed in 8 min. Moreover, repetitive tests imply the good recyclability and stability of the catalysts. The enhanced photocatalytic activity was largely ascribed to the efficient separation of photogenerated electron–hole pairs and high BET surface area of the catalysts. In addition, a possible mechanism on basis of the experimental results was discussed.