In this study, the Ag3PO4 microcrystal was successfully prepared at different temperatures using precipitation and hydrothermal methods. The as-prepared products were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (UV vis DRS) and so on. It was found that the synthesized temperature had some effects on the morphologies and photocurrent of Ag3PO4. As the synthesized temperature increased from 20 degrees C to 120 degrees C, the ratio of exposed (110) facets increased, which are the active photocatalysis facets in Ag3PO4 crystals, along with a higher photocatalytic efficiency over RhB under visible light irradiation. And the Ag3PO4 microcrystals synthesized at 120 degrees C exhibited the highest photocatalytic activities with the degradation ratio of RhB rising up to 97.83% in 6 min due to the high separation efficiency of electron and hole pairs. In addition, the main active species and their roles were investigated by adding scavengers (isopropyl alcohol and EDTA) during the photocatalytic degradation of RhB and a possible mechanism was discussed. (C) 2015 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

A novel heterojunction photocatalyst CdWO4/BiOBr was fabricated combining nano-rod CdWO4 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% CdWO4/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 CdWO4.

In this study, C3N4/Zn(1-x)Cd(x)S (0 ≤ x ≤ 1) heterostructures with adjustment of the band gap were successfully prepared by calcination and a hydrothermal synthesis method. The photocatalytic properties of C3N4/Zn(1-x)Cd(x)S composite photocatalysts were evaluated by the photocatalytic degradation of RhB under visible light irradiation. The results showed that the combination of the two semiconductor photocatalysts (C3N4 and Zn(1-x)Cd(x)S) greatly enhanced the photocatalytic degradation efficiency of RhB compared to the pure C3N4 and Zn(1-x)Cd(x)S under visible light irradiation. Among them, the 0.1C3N4/Zn0.8Cd0.2S composite photocatalyst exhibited the highest photocatalytic activities with the degradation efficiency of RhB arriving to 97.9% within 90 min. The remarkable photocatalytic activity of the 0.1C3N4/Zn0.8Cd0.2S composite photocatalyst was mainly attributed to the appropriate band structure and the effective separation of photogenerated electron-hole pairs. Additionally, a possible basic mechanism of the composite semiconductor photocatalytic process was also discussed. Moreover, it was also investigated that O2(˙⁻) and h(+) were the main reactive oxidative species in this photocatalytic process of the degradation of RhB on the 0.1C3N4/Zn0.8Cd0.2S heterostructure photocatalyst.

•The zinc-doped CdWO4 photocatalyst was synthesized by a hydrothermal process.•The Zn-doped CdWO4 exhibited excellent photocatalytic efficiency.•Zinc effect on photocatalytic activity and photodegradation mechanism were investigated.

In this study, a novel ZnS/ZnWO4 nanocomposite photocatalyst was synthesized through a facile hydrothermal synthesis method. The as-prepared samples were characterized by energy dispersive X-ray analysis (EDS), X-ray powder diffraction (XRD), transmission electron microscopy (TEM), UV-vis diffuse reflectance spectroscopy (UV-vis DRS) and so on. The ZnS/ZnWO4 nanocomposite shows an enhanced photocatalytic activity for the degradation of rhodamine B (RhB) under simulated solar light. The results show that ZnS/ZnWO4 nanocomposite photocatalysts have better photocatalytic activity than the single ZnWO4 or ZnS. In the case of ZnS compounding, ZnS/ZnWO4 photocatalyst led to the lower recombination ratios of photo-generated electron hole pairs and then higher photocatalytic performance. In addition, it has the potential to become a useful technology for environmental cleanup without secondary pollution.

In the present paper, the Co-doped Fe 3 O 4 nanoparticles have been successfully synthesized by the co-precipitation process. The morphologies size of the Co-doped Fe 3 O 4 nanoparticles were characterized using scanning electron microscopy (SEM). The structure of the products were characterized by Xray diffraction (XRD). The composition of the product was analyzed by energy dispersive X-ray detector (EDS). The results show that the phase structure of the Co-doped Fe 3 O 4 nanoparticles is spinel Fe 3 O 4 with the particle size ranging from 40 to 50 nm. The prepared Co-doped Fe 3 O 4 nanoparticles electrode was then applied to detect hydrogen peroxide (H 2 O 2 ) in 0.01 M pH 7.0 phosphate buffer medium.

A core–shell nanostructured magnetic photocatalyst Fe3O4@SiO2@Ag3PO4 with a grain size ranging from 200 to 400 nm was prepared via a facile and effective method. The as-prepared products were characterized using X-ray diffraction, high-angle annular dark field-scanning transmission electron microscopy, energy-dispersive spectroscopy, and UV–Vis diffuse reflectance spectra. The photocatalytic activity was evaluated by the degradation of 10−5 M RhB solution under visible light irradiation with a cut-off filter (λ ≥ 420 nm). The results showed that nearly 100 % color removal efficiency was achieved in 45 min with the presence of Fe3O4@SiO2@Ag3PO4 photocatalyst. Furthermore, it can be easily recollected from the solution by magnetic separation and efficiently recycled without major loss of activity due to its superior magnetic responsibility and extremely high reusability, exhibiting highly potential applications in water purification avoiding the secondary pollution.