In situ ion exchange synthesis of the novel Ag/AgBr/BiOBr hybrid with highly efficient decontamination of pollutants

A scalable synthesis technique of hierarchical BiOBr microspheres for advanced visible light photocatalyst

A facile and efficient solvothermal fabrication of three-dimensionally hierarchical BiOBr microspheres with exceptional photocatalytic activity

Hierarchical BiOBr microspheres were successfully synthesized via a solvothermal method by using the diethylene glycol(DEG) as the solvent and soft‐template. The as‐obtained products were characterized by X‐ray powder diffraction (XRD), scanning electron microscopy (SEM), selected area electron diffraction (SAED), high resolution transmission electron microscopy (HRTEM), N2 adsorption–desorption and UV–Vis diffuse reflectance spectroscopy(DRS) techniques. The formation mechanism for the growth of hierarchical BiOBr microspheres has been studied. The possible mechanism of photocatalysis has been discussed. Remarkably, the as‐prepared BiOBr microspheres has a large specific surface area, which can reach a maximum surface area of 55.9307 m2/g. In addition, the superior enhanced photocatalytic activities of BiOBr microspheres were evaluated by the photodegradation of methyl orange (MO) and Rhodamine B (RhB) under visible‐light illumination, which presented the efficiency up to 98.10% just within 50 min and 98.64% within 30 min, respectively. BiOBr microspheres can be a promising candidate as highly efficient photocatalyst for decompositing of organic contaminants for environmental remediation.

Hierarchical BiOBr microspheres with oxygen vacancies synthesized via reactable ionic liquids for dyes removal

Novel BiOBr hierarchical microspheres have been successfully prepared via a facile microwave‐assisted solvothermal route and used for visible‐light photocatalytic degradation of RhB. The phase and morphology of the products were characterized by powder X‐ray diffraction (XRD), thermogravimetric analysis (TG), scanning electron microscopy (SEM), BET, and UV‐vis diffuse reflectance spectra. The SEM observations displayed that BiOBr flower‐like nanostructure assembled from nanosheets. The BiOBr flower‐like nanostructure, with a narrow band gap (2.63 eV), shows excellent photocatalytic activity in the degradation of RhB dye under visible‐light, much higher than those of BiOBr nanosheet and P25 photocatalysts.

Visible-light-induced charge transfer pathway and photocatalysis mechanism on Bi semimetal@defective BiOBr hierarchical microspheres

Visible light photocatalytic performance of hierarchical BiOBr microspheres synthesized via a reactable ionic liquid

SDS-assisted solvothermal synthesis of BiOBr microspheres with highly visible-light photocatalytic activity

Study on photocatalytic activity of Er3+:YAlO3/TiO2 composite films supported on electrically conductive glass (FTO) in visible-light photocatalytic degradation of organic dye

Chapter 18 - Magnetic nanoparticles and nanocomposites for the applications of photocatalytic degradation of organic dyes

Semiconducting nanomaterials based heterogeneous photocatalysis represent a low-cost, versatile technique for environmental remediation, including pollution mitigation, energy management and other environmental aspects. Herein, we demonstrate the syntheses of various heterogeneous photocatalysts based on highly reduced graphene oxide (HRG) and vanadium oxide (VOx)-based nanocomposites (HRG–VOx). Different shapes (rod, sheet and urchin forms) of VOx nanoparticles were successfully fabricated on the surface of HRG under solvo-/hydrothermal conditions by varying the amount of water and ethanol. The high concentration of water in the mixture resulted in the formation of rod-shaped VOx nanoparticles, whereas increasing the amount of ethanol led to the production of VOx sheets. The solvothermal condition using pure ethanol as solvent produced VOx nano-urchins on the surface of HRG. The as-prepared hybrid materials were characterized using various spectroscopic and microscopic techniques, including X-ray diffraction, UV–vis, FTIR, SEM and TEM analyses. The photocatalytic activities of different HRG–VOx nanocomposites were investigated for the photodegradation of methylene blue (MB) and methyl orange (MO). The experimental data revealed that all HRG–VOx composite-based photocatalysts demonstrated excellent performance toward the photocatalytic degradation of the organic dyes. Among all photocatalysts studied, the HRG–VOx nanocomposite consisting of urchin-shaped VOx nanoparticles (HRG–VOx-U) demonstrated superior photocatalytic properties towards the degradation of dyes.

BiPO4/BiOBr p–n junction photocatalysts: One-pot synthesis and dramatic visible light photocatalytic activity

In this work, an efficient photocatalyst based on β-cyclodextrin-glycine-modified TiO2 nanoparticles (TiO2-Gly-βCD NPs) was successfully synthesized. The photocatalytic activity of the prepared TiO2-Gly-βCD was tested on the degradation of methylene blue (MB) and methyl orange (MO) dyes. The enhanced surface properties of TiO2-Gly-βCD photocatalyst generated excellent photocatalytic performance for the photocatalytic degradation of dyes in aqueous solution. These were strongly attributed to the presence of the functional hydroxyl groups and the inner cores of the hydrophobic cavity in β-CD to form inclusion complexes with organic molecules. As compared to the pure TiO2 and TiO2 modified by Gly, the dye degradation rate under UV irradiation was considerably enhanced by TiO2/Gly/βCD as a photocatalyst. In addition, the sonocatalytic degradation of dyes was investigated, and it was found that the ultrasonic waves slightly enhanced the degradation time of dyes. The results indicated that the first-order kinetic model well describes the degradation of MB and MO dyes by TiO2-Gly-βCD. Furthermore, the chemical oxygen demand (COD) values were determined for real industrial wastewater and treated wastewater.

In this study, hierarchical BiOBr microspheres were synthesized via a one-pot solvothermal method in the presence of imidazole ionic liquids. The resultant samples were characterized by XRD, SEM, HRTEM, PL, EPR, EIS and UV-vis absorption spectroscopy. The photoactivity of BiOBr was evaluated by the photocatalytic degradation of methyl orange (MO) and tetracycline hydrochloride. Oxygen vacancies were detected in the system and proven to be correlated with the activity of the catalyst. It was also revealed that BiOBr microspheres prepared by 1-butyl-3-methylimidazolium bromide at 433 K for 8 hours displayed a superior performance compared to the other samples in the degradation of model organic contaminants. After 4.5 hours of reaction, the highest degradation efficiency of 94.0% was achieved by BiOBr-C4-Br. Stronger photoluminescence spectral intensities could be obtained as the cationic chain lengths of the ionic liquids reduced gradually. According to our experiments, the better performance of BiOBr-C4-Br in the degradation of model pollutants can be attributed to the effect of oxygen vacancies. The findings of our work may have important implications for the design of BiOBr.

In this study, Ag deposited TiO2 (Ag/TiO2) composites were prepared by three different methods (Ultraviolet Irradiation Deposition (UID), Vitamin C Reduction (VCR) and Sodium Borohydride Reduction (SBR)) for the visible-light photocatalytic degradation of organic dyes in magnetic field. And then the prepared Ag deposited TiO2 (Ag/TiO2) composites were characterized physically by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The visible-light photocatalytic activities of these three kinds of Ag deposited TiO2 (Ag/TiO2) composites were examined and compared through the degradation of several organic dyes under visible-light irradiation in magnetic field. In addition, some influence factors such as visible-light irradiation time, organic dye concentration, revolution speed, magnetic field intensity and organic dye kind on the visible-light photocatalytic activity of Ag deposited TiO2 (Ag/TiO2) composite were reviewed. The research results showed that the presence of magnetic field significantly enhanced the visible-light photocatalytic activity of Ag deposited TiO2 (Ag/TiO2) composites and then contributed to the degradation of organic dyes.