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The major problems of the semiconductor nanomaterials in the photocatalytic applications for degradation of organic contaminants are fast recombination of photogenerated electron-hole pairs and low visible light harvesting. Therefore, we tried to resolve these drawbacks by coupling LaFeO 3 nanoparticles with Bi 2 WO 6 nanoflakes and constructing of binary Z-scheme heterojunction through the facile solvothermal synthesis approach. The photocatalytic activity of the LaFeO 3 /Bi 2 WO 6 heterojunction was studied through degradation of tetracycline (TC) upon visible light irradiation. The effects of experimental parameters, including LaFeO 3 /Bi 2 WO 6 dosage, initial concentration of TC, visible light irradiation time, and solution pH on the photocatalyst performance of binary nanocomposite were analyzed by response surface methodology. The results of analysis of variance confirmed that these parameters have a significant effect on the TC degradation efficiency. The value of the first-order kinetic rate constant for removal of TC using LaFeO 3 /Bi 2 WO 6 was calculated 0.1291 min−1, which was 20 and 10 times higher than pure LaFeO 3 and Bi 2 WO 6 , respectively. Besides, LaFeO 3 /Bi 2 WO 6 was shown the excellent photocatalytic stability after 4 cycles. Furthermore, the photocatalytic pathway for photodegradation of TC by binary LaFeO 3 /Bi 2 WO 6 nanocomposite was proposed according to the trapping experiments of active species and the results were signify that the h+ and . OH are the predominant reactive species for the photodegradation of TC. Overall, we believe that current novel research opens a promising route for the preparation of highly efficient LaFeO 3 /Bi 2 WO 6 photocatalyst and its usage for wastewater treatment. [ABSTRACT FROM AUTHOR]

In this research, a novel KIT‐5/Bi2S3‐Fe3O4 nanocomposite was prepared. The structure and morphology properties of the nanocomposite were well characterized by XRD, FESEM‐EDS‐mapping, TEM, and N2 adsorption–desorption. Benefiting from the visible light, the as‐prepared KIT‐5/Bi2S3‐Fe3O4 nanocomposite exhibit significantly improved photocatalytic performance for the degradation of parathion. The optimum photocatalytic efficiency of KIT‐5/Bi2S3‐Fe3O4 nanocomposite was investigated with the central composite design using Design Expert software. The four critical variables affecting parathion degradation such as the concentration of parathion, pH, irradiation time, and amount of KIT‐5/Bi2S3‐Fe3O4 nanocatalyst. A polynomial function corresponding to degradation percent was obtained for the experimental data. The results showed that this catalyst has a good performance for the degradation of parathion. [ABSTRACT FROM AUTHOR]

In the present research, Fe3O4 and WS2 nanoparticles immobilized on or in KIT‐6 (KIT: Korea Institute of Science and Technology) pores (KIT‐6/WS2‐Fe3O4) were synthesized and studied as a photocatalyst for degradation of representative chlorpyrifos as an organophosphorus pesticide. In addition, the KIT‐6/WS2‐Fe3O4 photocatalyst was characterized by different methods such as TEM, FESEM‐EDS‐Mapping, XRD, and N2 adsorption/desorption surface area, in order to understand their morphology, structural, and physical properties. The photocatalytic performance of this photocatalyst was investigated for degradation of chlorpyrifos by visible light irritation. The effects of variables such as chlorpyrifos concentration, KIT‐6/WS2‐Fe3O4 nanocatalyst amount, pH, and irradiation time on chlorpyrifos degradation efficiency was studied by central composite design with response surface methodology. The optimum conditions for CP degradation were obtained by 50 mg KIT‐6/WS2‐Fe3O4 nanocatalyst, and 7.2 ppm chlorpyrifos solution with pH = 6, at 52 min. The pseudo‐first‐order model with rate constants equal to 0.069 min−1 as best choice efficiency described the chlorpyrifos degradation process according to Langmuir‐Hinshelwood kinetic. [ABSTRACT FROM AUTHOR]

In this work, the photocatalytic activity of the synthesized graphene oxide (GO)‐Fe3O4/TiO2 mesoporous photocatalysts was evaluated using chlorpyrifos (CP) as a contaminant. The nano‐photocatalyst was characterized by X‐ray diffraction, field emission scanning electron microscopy with energy‐dispersive X‐ray spectroscopy, transmission electron microscopy, and specific surface area by the Brunauer–Emmett–Teller method. Using visible light, the GO‐Fe3O4/TiO2 mesoporous photocatalyst was investigated on the degradation of CP pesticide. The GO‐Fe3O4/TiO2 photocatalyst displayed a good photocatalytic activity, which was achieving 97% of CP degradation after 60 min. Finally, experiments were performed to evaluate GO‐Fe3O4/TiO2 mesoporous nanocatalyst activity on repeated applications; after several uses, its photocatalytic activity was retained, which indicated stability. [ABSTRACT FROM AUTHOR]

• Preparation of a novel and efficient CuO/TiO 2 /PANI photocatalyst by in-situ polymerization of PANI. • Superior photocatalytic activity of CuO/TiO 2 /PANI for chlorpyrifos degradation in water under visible light irradiation. • A Z-scheme mechanism for photocatalytic degradation of chlorpyrifos using CuO/TiO 2 /PANI nanocomposite. • Reusability of CuO/TiO 2 /PANI photocatalyst after five photocatalysis run. Visible light active photocatalyst, copper oxide/titanium dioxide/polyaniline (CuO/TiO 2 /PANI) nanocomposite, have been synthesized and utilized for chlorpyrifos degradation in water. The nanocomposite was characterized by some techniques including field emission scanning electron microscopy (FE-SEM), Fourier-transform infrared spectroscopy (FT-IR), and diffuse reflectance spectroscopy (DRS). The structural properties confirmed that the nanocomposite was successfully prepared and optical properties revealed that the nanocomposite can be operated by visible light irradiation. The resulting nanocomposite was employed as photocatalyst to degrade chlorpyrifos in water and 95 % of pesticide was photo-degraded within 90 min illumination. Some parameters affecting the photocatalytic reaction such as pH, pesticide initial concentration, irradiation time and photocatalyst amount were optimized. The CuO/TiO 2 /PANI nanocomposite presented higher photocatalytic activity in comparison with CuO/TiO 2 and TiO 2 /PANI under the same conditions. According to the obtained results, the nanocomposite band gap has been decreased, leading to decrease the recombination rate of photo-generated charges. That is why the nanocomposite catalytic efficiency has been improved. [ABSTRACT FROM AUTHOR]

In this research, the photocatalytic degradation of the pesticide pollutant was investigated using titanium nanoplates decorated by Pd and Fe 3 O 4 nanoparticles immobilization on graphene oxide nanosheets (TNP-Pd-Fe 3 O 4 /GO). This nanocatalyst was characterized by XRD, FESEM-EDS-Mapping techniques. As-synthesized TNP-Pd-Fe 3 O 4 /GO was tested for photocatalytic activity by the degradation of the pesticide pollutant, parathion under visible light irradiation. The effect of catalyst amount, initial parathion concentration and pH were studied on photocatalytic degradation of parathion by the design of the experimental method in presence of TNP-Pd-Fe 3 O 4 /GO nanocomposite. The central composite design modeling, based on response surface methodology, was used for this object. In addition, the kinetics of parathion degradation was studied by the Langmuir- Hinshelwood equation. [ABSTRACT FROM AUTHOR]

Here, the TiO2-NiO magnetic on graphene oxide nanostructure were synthesized and after characterization was used as photocatalyst for degradation of organophosphorus pesticides under visible light irradiation. Parameters affecting the process including photocatalyst amount, pesticide concentration, pH, radiation time, and temperature effect on the percentage of imidacloprid degradation were investigated and optimized. The degradation percent of organophosphorus pesticides was carried out using UV–Vis spectrophotometer. In order to optimize the parameters affecting the degradation process, the response surface method was successfully applied. The results indicate that GO/Fe3O4/TiO2-NiO could act as a suitable photocatalyst in the degradation of Imidacloprid. Imidacloprid (IC) pesticide is used as a poison for a specific group of living organisms. On the other hand, modern insecticides in the aquatic environment will have serious problems for humans and other living organisms. Photocatalytic degradation can be a promising way to improve water. In the present work, the TiO 2 -NiO magnetic on nanostructure graphene oxide nanosheets were synthesized using the sol–gel method and after characterization was used as photocatalyst for degradation of organophosphorus pesticides under visible light irradiation. Parameters affecting the process including photocatalyst amount, pesticide concentration, pH, radiation time, and temperature effect on the percentage of imidacloprid degradation were investigated and optimized. The degradation percent of organophosphorus pesticides was carried out using UV–Vis spectrophotometer. In order to optimize the parameters affecting the degradation process, the response surface method (RSM) was successfully applied. The response surface method is based on the central composite design (CCD). The CCD was successful in optimizing the photocatalytic degradation of imidacloprid pesticide. The pH, photocatalyst amount, the concentration of imidacloprid pesticide were investigated and the second-order variance (ANOVA) analysis showed that the predicted values correspond with the results of the experiment. The results indicate that GO/Fe 3 O 4 /TiO 2 -NiO could act as a suitable photocatalyst under visible light in the degradation of organophosphorus pesticides. [ABSTRACT FROM AUTHOR]

• Successful synthesis of g-C 3 N 4 /Cu/TiO 2 composite as a photocatalyst. • High photocatalytic performance of the composite under visible light irradiation. • 60% degradation of endosulfan in aqueous medium after 80 min irradiation. • Enhanced photocatalytic activity compared to pure g-C 3 N 4 and Cu/TiO 2. The g-C 3 N 4 /Cu/TiO 2 (graphitic-carbon nitride/copper/titanium dioxide) nanocomposite as a photocatalyst was developed to degrade endosulfan, a very poisonous pesticide, in an aqueous medium under visible light irradiation. The structure, morphology, and optical properties of the synthesized nanocomposite were determined using SEM, XRD, FT-IR, DRS, EDX, and PL. The obtained results showed that incorporating the Cu and TiO 2 molecules onto g-C 3 N 4 led to enhance absorption ability in the visible region, as well as improved the separation of photo-excited electron–holes. Some operational factors such as initial pesticide concentration, pH, and the presence of anions were studied in the photocatalytic degradation of endosulfan. The 60% photocatalytic performance was achieved by 80 min irradiation of the endosulfan solution, which was three times higher than pure g-C 3 N 4. The improved photodegradation efficiency probably arose from the synergistic effect between three components of the composite photocatalyst. [ABSTRACT FROM AUTHOR]

[Display omitted] • PANI/ZnO-CoMoO 4 as a great photocatalyst for degradation of imidacloprid. • The high photocatalytic behavior under visible irradiation. • Investigating effective factors in degradation of imidacloprid by experimental design. Structural design in a semiconductor photocatalyst is significant to improve the photocatalytic efficiency to solve current energy or environmental problems. In this study, we developed a Z-scheme photocatalyst system consisting of PANI/ZnO-CoMoO 4 for degradation photocatalytic processes. The structural composition and morphologies of the PANI/ZnO-CoMoO 4 nanocomposite were analyzed by FTIR, FESEM-EDS, and XRD techniques. Subsequently, the pesticide-degradation experiments were performed for the degradation of imidacloprid (IM) using as-synthesized PANI/ZnO-CoMoO 4 nanocomposite under visible-light irradiation to investigate its photocatalytic activity. The influence of PANI/ZnO-CoMoO 4 amount, pH, and IM concentration on the performance of the degradation reaction has been considered by the experimental design. Under optimal conditions (4.5 ppm of IM, pH = 4, and 163.5 mg photocatalyst), about 97% of the IM was degraded within 180 min of irradiation. The prepared photocatalyst can be readily recovered and reutilized with the centrifugation process. [ABSTRACT FROM AUTHOR]