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Photocatalytic activity of gadolinium doped TiO <sub/>2</sub> particles for decreasing heavy metal chromium (VI) concentration
摘要: Titanium dioxide (TiO2) is among the most potential photocatalyst. However, TiO2 only works under UV light due to the relatively wide band gap energy. To overcome this, TiO2 is infiltrated (doped) by rare earth elements such as gadolinium (Gd). TiO2 was synthesized using sol gel method, while Gd/TiO2 photocatalyst was synthesized by the mixing methods of sol-gel and impregnation. The crystals are then characterized using XRD and SEM-EDX. The XRD diffractogram demonstrated that the crystallinity synthesized of TiO2 had an anatase structure similar to the structure of anatase P-25 as references. The SEM-EDX showed that Gd ion could not enter the crystal lattice, but only dispersed on the surface of TiO2 particles. The optimum result of decreased Cr(VI) concentration was reported using Gd/TiO2 1% w/w by a decrease of up to 94%, after irradiated with ultraviolet for one hour.
关键词: sol-gel method,gadolinium doping,TiO2,Cr(VI) concentration,photocatalyst
更新于2025-09-04 15:30:14
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Preparation and Comparison of Magnetic Nanoparticles and Magnetic Nanoparticles Doped with Cobalt for Photodegradation of Methyl Orange
摘要: This paper describes a study in which magnetic nanoparticles were fabricated via co-precipitation approach. These nanoparticles were then coated with cobalt as a means of enhancing their photocatalytic activity. A variety of different instruments were used to characterize the magnetic nanoparticles including transmission electron microscopy, X-ray diffraction analysis, and scanning electron microscope. They were then tested to determine the extent to which they could effectively degrade harmful dyes in the form of was methyl orange under UV lamp irradiation (365 nm). The performance of standard magnetic nanoparticles was compared with those coated with cobalt in terms of removal of methyl orange to determine the extent to which Co-doped magnetic nanoparticles can more effectively facilitate the photocatalytic degradation of methyl orange in comparison to standard magnetic nanoparticles.
关键词: Nanoparticles,Photocatalyst,Photocatalytic degradation,Methyl orange,Co-doped Fe3O4
更新于2025-09-04 15:30:14
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PPECu/NiFe2O4 as an efficient visible-light-driven difunctional photocatalyst for degradation of PPCPs and hydrogen production
摘要: A simple coprecipitation method has been used to prepare PPECu/NiFe2O4 composites. The as-prepared samples were studied by XRD, FE-SEM, TEM, EDS and UVevis Drs. The loading of NiFe2O4 not only enhanced the visible light absorption intensity of composites, but also promoted the separation of photogenerated electron-hole pairs. Cocatalyst NiFe2O4 made the PPECu/NiFe2O4 composites possessed better activities for TC degradation and hydrogen production than pure PPECu. Among the composite photocatalysts, P-NFO-5 exhibited the highest activity with the degrade ef?ciency of 98% (20 min) and hydrogen evolution yield of 35.8 mmol/g (3.0 h) under visible light irradiation. Furthermore, a possible mechanism for the ef?cient PPECu/NiFe2O4 composite has been discussed.
关键词: NiFe2O4,Photodegradation,PPECu,Photocatalytic hydrogen production,Difunctional photocatalyst
更新于2025-09-04 15:30:14
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Improvement of photocatalyst properties of magnetic NPs by new anionic surfactant
摘要: In this research, Fe3O4 NPs was synthesized by co- precipitation approach. Then SiO2 shell was grown on the Fe3O4 core. Synthesized NPs were characterized by means of XRD, FTIR, VSM, TGA, SEM and TEM. The magnetic properties of core and core-shell NPs was 74 and 42 emu/g, respectively. The TEM picture of core-shell was showed thickness shell of SiO2 on the Fe3O4 NPs. The size of this shell about 2.5nmWhich caused the core magnetic property to be well preserved. Photocatalyst activity of the synthesized NPs was investigated by using methyl orange (MO) and methylene blue (MB) as pollutant at different pH. For first time sodium citrate was used to improvement photo- degradation. The Fe3O4 indicated good photocatalyst activity for photo-degradation and it’s activity was considerably increased after SiO2 shell growth.
关键词: Fe3O4@SiO2,Photocatalyst,Tri sodium citrate,Fe3O4,Anionic surfactant
更新于2025-09-04 15:30:14
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Optimization of CdS/TiO2 Nanotube-Array Composite Photocatalysts Prepared by Electrodeposition
摘要: Titania nanotube arrays were prepared by titanium anodizing, then CdS/TiO2 nanotube arrays composite photocatalysts were prepared by an AC electrodeposition method for different times. The morphology and crystal structure of the CdS/TiO2 composite photocatalysts were characterized by SEM and XRD. The photoelectrochemical properties of the composites were investigated by means of UV-visible absorption spectra and photocurrent measurements. The photocatalytic activity was evaluated by the degradation of methyl orange under UV-visible light irradiation. The results show that there is an optimum deposited time for the highest photocatalytical activity of the CdS/TiO2 composite photocatalysts under UV-visible light irradiation and the optimum deposited time is determined to 3 min.
关键词: Electrodeposition,Nanotube array,Composite photocatalyst,Methyl orange,CdS/TiO2
更新于2025-09-04 15:30:14
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Fabrication of ternary visible-light-driven semiconductor photocatalyst and its effective photocatalytic performance
摘要: Heterogeneous semiconductor photocatalysis has been considered as a cost-effective alternative for the eliminating hazardous pollutants and generating sustainable energy. Graphene, a 2D allotrope of carbon, has received significant attentions due to its outstanding properties. In this work, a highly efficient visible-light-driven ternary heterostructure semiconductor RGO/Ag2O/Ag2WO4 (RGAAW) Ag-based photocatalyst was prepared and its photocatalytic activity was evaluated by photodegradation of methylene orange (MO). The morphology, structure and optical absorption properties of the as-prepared RGAAW were characterized by SEM, XRD, XPS, FT-IR and UV?vis DRS, respectively. The obtained result was found that the as-prepared RGAAW exhibited the excellent photocatalytic activity, which was almost 11.5 and 7 times as high as those of individual Ag2O and Ag2WO4, respectively. The enhancement of photocatalytic performance could be attributed to the reduced graphene oxide sheets can function as an electron collector and transporter to lengthen the lifetime of the charge carriers. Moreover, the as-prepared RGAAW showed excellent stability toward the photodegradation of methyl orange (MO). The possible mechanism of photocatalytic activity enhancement was proposed.
关键词: environmental pollutants,visible-light-driven,Photocatalyst
更新于2025-09-04 15:30:14
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Fabrication of Ag@AgCl with Enhanced Plasmonic Photocatalysis Performance via a Deep Eutectic Solvent
摘要: The plasmonic photocatalyst Ag@AgCl was successfully prepared through a facile solvothermal method via a deep eutectic solvent (DES), which is composed of choline chloride and urea. X-Ray diffraction, scanning electron microscopy, energy-dispersive X-ray, element-mapping, X-ray photoelectron spectroscopy, N2 absorption–desorption, and UV-vis diffuse reflectance techniques were adopted to analyse the performance of the plasmonic photocatalyst. Characterisation results indicated that the DES not only served as a solvent and Cl source, but also as a reductant. Meanwhile, the probable mechanism for the formation of Ag@AgCl is discussed, which revealed a visible light enhanced photocatalytic property for the degradation of benzidine. Furthermore, the photocatalyst showed no decrease in its catalytic activity even after five cycles of operation. Finally, a possible photocatalytic oxidation mechanism of Ag@AgCl is proposed.
关键词: solvothermal method,photocatalytic degradation,plasmonic photocatalyst,Ag@AgCl,deep eutectic solvent
更新于2025-09-04 15:30:14
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Synthesis of Cu-Doped Ti-Containing MCM-41 and its Photocatalytic Performance for Indoor Air Purification
摘要: The prepared catalysts were synthesized in a mild way and characterized by various analytical instruments including X-ray diffraction, nitrogen physisorption, UV-visible spectroscopy, high resolution-transmission electron microscopy and X-ray photoelectron spectroscopy. All samples exhibited the typical mesoporous structure and spherical structure. Copper and titanium species in the MCM-41 support were well anchored on the mesoporous framework in the form of metal oxides. The adsorption tests for formaldehyde examined the positive effect of metal incorporation. In the static state test, MCM-41 adsorbed 31 % of formaldehyde and Ti/Cu-MCM-41 elevated this value to 41 %. Moreover, Ti/Cu-MCM-41 demonstrated the superior photocatalytic performance under both UV- and visible-light irradiation, achiveing 57 % and 18 % of formaldehyde degradation at the end of reaction, respectively. With the X-ray photoelectron spectroscopy and UV-Visible results, an intense interaction between Ti and Cu was observed and the synergy effect mechanism in the bimetallic catalyst was proposed.
关键词: MCM-41,Cu-Doped Ti,Air purification,Photocatalyst
更新于2025-09-04 15:30:14
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Switching on efficient photocatalytic water oxidation reactions over CaNbO2N by Mg modifications under visible light illumination
摘要: In spite of a strong visible light absorbance as far as 600 nm, CaNbO2N generally exhibits poor photocatalytic activity under normal conditions because of various structural defects and poor charge mobility. In this work, we have synthesized a series of Mg-modified CaNbO2N, i.e. CaNb1-xMgxO2+yN1-y (0 ≤ x ≤ 0.2), and performed a detailed investigation on their crystal structures, optical absorption and other physicochemical properties. Our results show that there is a slight shrinkage of the unit cell and a blue-shift of absorption edges upon Mg incorporation into CaNbO2N. The nitrogen contents as well as defects levels can be effectively tuned by altering the content of Mg. More strikingly, photocatalytic oxygen productions are much improved after Mg modifications under visible light irradiation (λ ≥ 420 nm). An average oxygen production rate as much as ~126.8 umol h?1 and an apparent quantum efficiency as high as ~3.4 % at 420 ± 20 nm is achieved for CaNb0.9Mg0.1O2+yN1-y (x = 0.1). These improvements probably stem from a substantial decrease of Nb4+ defects in CaNbO2N as well as slight positive shift of valence band maximum (VBM) after Mg modifications. Meanwhile, photoelectrochemical analysis suggests charge migration is somewhat enhanced in response to Mg modifications.
关键词: water oxidation,CaNbO2N,photocatalyst,water splitting,Mg modification
更新于2025-09-04 15:30:14
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Highly efficient multifunctional Ag/TiO2 nanotubes/Ti plate coated with MIL-88B(Fe) as a photocatalyst, adsorbent, and disinfectant in water treatment
摘要: Multifunctional MIL-88B(Fe)–Ag/TiO2 nanotubes/Ti plates were prepared via dip-coating process. Pollutant removals from aqueous solutions were investigated using three different reactions: (1) adsorption of heavy metal ion (Pb2+ and Cd2+), (2) photocatalytic degradation of methyl orange dye (MO), and (3) antibacterial effect for Escherichia coli (E. coli) degradation. Photocatalytic results for dye degradation under UV light irradiation proved the highest activity of the MIL-88B(Fe)–Ag/TiO2 nanotubes/Ti plates. The degradation rate constant of MIL-88B(Fe)–Ag/TiO2 nanotubes/Ti plates was approximately four times as that of pure TiO2 nanotubes/Ti under UV irradiation. In addition, this plate showed the effective removal of heavy metal ions by sorption process. The adsorption of Pb2+ and Cd2+on the MIL-88B(Fe)–Ag/TiO2 nanotubes/Ti plates reached a maximum capacity of 113 and 138 mg/g, and this value was approximately 1.6 times as that of pure TiO2 nanotubes/Ti. In addition, the multifunctional composite plates demonstrated great antibacterial activities towards E. coli. All bacteria colonies killed after 60 min photocatalytic treatment on MIL-88B(Fe)–Ag/TiO2 nanotubes/Ti plates. The results show the importance of a cooperative effect between the MIL-88B(Fe) metal organic framework (MOF) and Ag/TiO2 nanotubes/Ti plates. The simultaneous removals of these pollutants with the high efficiency showed an facile approach for the polluted water treatment via the newly fabricated MIL-88B(Fe)–Ag/TiO2 nanotubes/Ti plate with multiple functions.
关键词: Photocatalyst,Ag/TiO2 nanotubes/Ti,MIL-88B(Fe),Water treatment,Disinfectant,Adsorbent
更新于2025-09-04 15:30:14