Photocatalytic activities of Cd-doped ZnWO4 nanorods prepared by a hydrothermal process

Ag nanoparticle-decorated chitosan/SrSnO3 nanocomposite for ultrafast elimination of antibiotic linezolid and methylene blue

Effective design of ultrafast new-generation photocatalysts is a challenging task that requires highly dedicated efforts. This research focused on the development and design of ultrafast smart ternary photocatalysts containing SrSnO₃ nanostructures in conjugation with chitosan (CTSN) and silver (Ag) nanoparticles by a very simple and straightforward methodology. Modern analytical tools such as FESEM, TEM, XRD, XPS, FTIR, and UV-Vis spectroscopy were employed to characterize the synthesized nanostructures. XRD and XPS analysis confirmed the successful creation of ternary organization among the Ag, CTSN, and SrSnO₃. The TEM images clearly confirmed that CTSN possessed overlapping micron-sized sheets with a layered morphology, whereas the undoped SrSnO₃ particles exhibited spherical and elongated shapes and particle sizes ranging from 20 to 80 nm. These particles were produced in high density with homogeneously distributed Ag nanoparticles (4-15 nm). The bandgap energy (E_g) for bare SrSnO₃, CTSN/SrSnO₃, and Ag@CTSN/SrSnO₃ nanocomposites was found to be 4.0, 3.94, and 3.7 eV, respectively. The photocatalytic efficiencies of all newly created photocatalysts were evaluated by considering an antibiotic linezolid drug and methylene blue (MB) dye molecule as target analytes. Among all investigated samples, the Ag@CTSN/SrSnO₃ photocatalyst was found to be highly superior, with ultrafast removal of the linezolid drug at 96.02% within 25 min and almost total removal of the MB dye in just 12 min under UV light irradiation. The Ag@CTSN/SrSnO₃ photocatalyst exhibited removal rate that was 3.36 times faster than that of bare SrSnO₃. The present report delivers a highly promising, extremely efficient, and very simple, straightforward treatment methodology for the effective destruction of lethal and notorious pollutants, enabling the appropriate management of current environmental concerns.

Preparation and application of one new supramolecular molybdenum oxygen cluster with adsorption of organic contaminants in wastewater

In this paper, one supermolecular compound, namely, p-[C20H18N2O4][Mo8O26]0.5·H2O (1) has been synthesized from 1,4-bis[4-nitrile-pyridine)-N-methylene]phenyldibromide (L1) and (NH4)6Mo7- O24·4H2O by hydrothermal method. The structure has been confirmed through single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra. The adsorption property of compound 1 has bee studied, Thus it’s much important to enrich the types of chemicals.

Preparation and application of two novel supramolecular polyoxmetalates with adsorption of organic contaminants in wastewater

Two new supramolecular polyoxmetalates were synthesized from 1, 4-bis[4-nitrile-pyridine)-N-methylene]phenyldibromide (L1) and 1, 2-bis[4-nitrile-pyridine)-N-methylene]phenyldibromide (L2) and (NH4)6Mo7–O24·4H2O under hydrothermal conditions. They are named p-[C20H18N2O4][Mo8O26] 0.5·H2O (1) and o-[C20H18N2O4][Mo8O26] ċ 0.5·H2O (2) respectively. The structures have been confirmed through single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra. The adsorption test of compound 1 and compound 2 in organic dyes were carried out. It was found that compound 1 had a good adsorption effect on methylene blue (MB) and rhodamine B (RhB). The adsorption effect of compound 2 on MB is stronger than that of compound 1.

ZnO Nanospheres Fabricated by Mechanochemical Method with Photocatalytic Properties

The preparation of high specific area (86.5 m2/g) ZnO nanospheres with good photocatalytic efficiency via a simple, green and efficient mechanochemical method was reported in this work. The products were characterized by XRD, SEM, TEM, BET and UV–Vis. The ball milling parameters were improved to reduce the agglomeration hazard during the ball milling process, and the specific surface area, band gap and photocatalytic efficiency were investigated in relation to ball milling time. Our study developed the opportunity for the low-cost and facile synthesis of a high specific surface area photocatalyst on a large scale for future industrial applications.

Rodlike Cadmium-Incorporated Zinc Tungstate Nanoarchitecture Fabricated by a Facile and Template-Free Strategy as a Photocatalyst for the Effective Degradation of Organic Pollutants in Sewage

Fabricating nanostructures and doping engineering are beneficial to tailor the photocatalytic activity of semiconductor materials, and the semiconducting photocatalysis is deemed to be one of the potential protocols to handle the environmental pollution and energy crisis issues. Herein, rodlike Cd-doped ZnWO4 Zn1-x Cd x WO4 nanoarchitectures were triumphantly prepared by a template-free strategy. The crystal structure, chemical state, optical, and photocatalytic features of the Zn1-x Cd x WO4 nanoarchitectures were studied using a variety of characterizations. The Zn1-x Cd x WO4 nanoarchitectures exhibit glorious photocatalytic performance compared with pristine ZnWO4 for the degradation of methyl orange in sewage. Mechanistic studies were executed for getting insights into the photocatalytic degradation process, and the remarkable photocatalytic property of the doped ZnWO4 nanoarchitectures is attributed to the boosted optical absorptive efficiency and the valid segregation and transmission of photogenerated charge carriers deriving from doping effects. The doped nanoarchitectures of this work have promising applications in the territories such as environment and energy chemistry, and the insight proposed in this work will contribute to develop other functionalized nanoarchitectures.

Synthesis of Ag and TiO2 modified polycaprolactone electrospun nanofibers (PCL/TiO2-Ag NFs) as a multifunctional material for SERS, photocatalysis and antibacterial applications

In this study, we reported the design and the fabrication of Ag and TiO₂ modified polycaprolactone (PCL) electrospun nanofiber (NF) mats. The as-prepared NF mats were fabricated by one-step electrospinning and it was exploited for three different purposes (i) reusable SERS substrate for quantitative analysis to trace organic pollutants, (ii) photocatalyst for degradation of organic pollutants and (iii) antibacterial agent for killing of bacteria. Three different nanofiber mats, PCL, PCL-TiO₂, PCL/TiO₂-Ag NFs. were fabricated and further investigated. The morphologies and structures of the as-prepared nanofiber mats were carried out using X-ray diffraction spectroscopy (XRD), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX) and fourier transform infrared spectroscopy (FT-IR) techniques. PCL/TiO₂-Ag NFs served as a highly effective SERS platform with a detection limit of 10 nM for the detection of methylene blue dye (MB). A remarkable feature of the presented platform is the ability to reuse the PCL/TiO₂-Ag NFs for SERS analysis of MB; availing from its capability for self-cleaning under UV light. By employing PCL/TiO₂-Ag NFs nanocatalyst, complete photocatalytic degradation of the probe analytes MB and ibuprofen (Ibu) under UV irradiation was accomplished not more than 180 min. Moreover, PCL/TiO₂-Ag NF mats showed a highly promising bactericidal feature against gram-negative Escherichia coli and gram-positive Staphylococcus aureus bacteria, which immensely emerged due to the presence of Ag NPs. This new trending nanofiber is assumed to lead a bunch of changes in the field of photocatalytic, SERS and antibacterial studies.

Surface Decoration of ZnWO₄ Nanorods with Cu₂O Nanoparticles to Build Heterostructure with Enhanced Photocatalysis

The surface of ZnWO₄ nanorods was decorated with Cu₂O nanoparticles (Cu₂O/ZnWO₄) prepared through a precipitation method. The Cu₂O nanoparticles were tightly deposited on the ZnWO₄ surface and had average diameters of 20 nm. The nanoparticles not only promoted the absorption and utilization of visible light but also facilitated the separation of photogenerated charge carriers. This brought an improvement of the photocatalytic activity. The 5 wt % Cu₂O/ZnWO₄ photocatalyst displayed the highest degrade efficiency for methylene blue (MB) degradation under visible light, which was 7.8 and 2 times higher than pure ZnWO₄ and Cu₂O, respectively. Meanwhile, the Cu₂O/ZnWO₄ composite photocatalyst was able to go through phenol degradation under visible light. The results of photoluminescence (PL), photocurrent, and electrochemical impedance spectra (EIS) measurements were consistent and prove the rapid separation of charge, which originated from the match level structure and the close contact with the interface. The radical and hole trapping experiments were carried out to detect the main active substances in the photodegradation process. The holes and ·O₂⁻ radicals were predicted to dominate the photocatalytic process. Based on the characterization analysis and experiment results, a possible photocatalytic mechanism for enhancing photocatalytic activity was proposed.

Perforated N-doped monoclinic ZnWO4 nanorods for efficient photocatalytic hydrogen generation and RhB degradation under natural sunlight

A perforated N-doped monoclinic ZnWO₄ nanorod photocatalyst for excellent hydrogen production via water splitting under sunlight.

Preparation and Photocatalysis of Nano-Zn/Ce Composite Oxides

Metal oxide photocatalysts often lead to partial or complete mineralization of organic pollutants. On irradiation with UV-visible light, metal oxides catalyze redox reactions in the presence of air and O2 and water. Using ascorbic acid as a new combustion agent, ZnO was rapidly synthesized. Nano-Zn/CeO2 composites were prepared by a heterogeneous-precipitation method using (NH4)2CO3 as precipitation agent. X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, Fourier-transform infrared spectrometry, ultraviolet spectrophotometry, and differential thermal analysis were used to analyse the microstructures of the synthesized materials. Differential thermal analysis, transmission electron microscopy, and X-ray diffraction analyses indicated that ZnO was coated by CeO2. Herein, a nano-Zn/Ce composite was explored as a catalyst for Rhodamine B photodegradation with a 125-W lamp as the UV radiation source in a batch reactor. The results show the photocatalytic properties of the nano-Zn/Ce composite were superior to ZnO, CeO2, and nano-Ce/Zn composites.

Synthesis and photocatalytic properties of ZnWO4 nanocrystals via a fast microwave-assisted method

High crystallinity of ZnWO4 nanoparticles has been successfully synthesized via a highly effective and environmentally friendly microwave route by controlling the reaction time and temperature. The products were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and Fourier infrared spectrum (FT-IR). The crystallinity was enhanced with the increase of the reaction temperature and time. The photocatalytic activities of ZnWO4 nanocrystals were evaluated by testing the photodegradation of rhodamine B (RhB) dye under ultraviolet (UV) light irradiation. The results indicated that as-prepared ZnWO4 was highly effective for the degradation of RhB. The degradation rate of RhB reached 98.01% after 6 h of UV illumination.

Synthesis and Activity of Ag-Doped Bi2WO6 Photocatalysts

Ag-doped Bi2WO6 photocatalysts were synthesized by hydrothermal method using from Bi (NO)3·5H2O, NH4VO3, and AgNO3 and further characterized by X-ray diffraction, Scanning electron microscopy, Energy dispersive X-ray detector (EDS) and UV-Vis diffusion reflectance spectra techniques. The photocatalytic activity of Ag-doped Bi2WO6 photocatalysts was evaluated by degrading RhB (10 mg/L) under visible light irradiation (λ > 420 nm). The results showed that in comparison with pure Bi2WO6 the photocatalytic activity of Ag-doped composite photocatalysts was improved significantly, and the degradation rate of RhB was increased about 26% when the Ag+ dopant concentration was 15%.

Photocatalytic activities of Mo-doped Bi2WO6 three-dimensional hierarchical microspheres

The Mo-doped Bi(2)WO(6) three-dimensional (3D) hierarchical microspheres from nanoplates have been synthesized by a hydrothermal route. The products were characterized in detail by multiform techniques: X-ray diffraction (XRD), energy-dispersive X-ray analysis (EDS), scanning electron microscopy (SEM), and UV-vis absorption spectrum. The results of the photocatalytic degradation of Rhodamine-B (RhB) in aqueous solution showed that molybdenum ions doping greatly improved the photocatalytic efficiency of Bi(2)WO(6) 3D hierarchical microspheres. The Mo-doped Bi(2)WO(6) microspheres with atomic ratio of Mo-W of 0.05 had the best activity in photodegradation of RhB in aqueous solution under 500 W Xe lamp light irradiation.

Exploration of CeO₂ nanoparticles as a chemi-sensor and photo-catalyst for environmental applications

CeO₂ nanoparticles were synthesized hydrothermally and utilized as redox mediator for the fabrication of efficient ethanol chemi-sensor. The developed chemi-sensor showed an excellent performance for electrocatalytic oxidization of ethanol by exhibiting higher sensitivity (0.92 μA∙cm⁻²∙mM⁻¹) and lower limit of detection (0.124±0.010 mM) with the linear dynamic range of 0.17 mM-0.17 M. CeO₂ nanoparticles have been characterized by field emission scanning electron microscopy (FESEM), Energy dispersive spectroscopy (EDS), X-ray powder diffraction (XRD), Raman spectrum, Fourier transform infrared spectroscopy (FTIR), and UV-visible absorption spectrum which revealed that the synthesized CeO₂ is an aggregated form of optically active spherical nanoparticles with the range of 15-36 nm (average size of ~25±10 nm) and possessing well crystalline cubic phase. Additionally, CeO₂ performed well as a photo-catalyst by degrading amido black and acridine orange.