Fabrication progress of selective and durable Ni2+-doped Ag3PO4 for visible-light degradation of various textile dyes

Effect of indium (III) doping on Ag3PO4 catalyst stabilization and its visible light photocatalytic activity toward toxic dyes in water

Indium(III)-doped Ag3PO4 (In-AgP) catalysts at different weight percentages were elaborated by co-precipitation and subjected to XRD, SEM, UV-vis DRS, and FTIR characterization. The prepared catalysts were of spherical morphology and their diameters depends on doping dosage. The whole materials crystallize in a centered cubic system with a slight dissimilation in the positions of the characteristic peaks as a function of indium dosage. The photocatalytic performance of the catalysts under visible light was investigated in the photocatalytic degradation of anionic dye (methyl orange (MO)) and cationic dye (auramine O (AO)) in moderate acid, neutral, and basic pH conditions. Results showed more selectivity to MO than AO. Furthermore, indium-doped samples are more active in the acidic medium than the pure Ag3PO4 (AgP), and 10%In-AgP catalyst presents the highest activity. The degradation efficiency reached 99 % in 60 min for MO and in 180 min for AO. In addition, a high recycling stability was achieved and the catalyst retains its degradation capacity above 99 % after five cycles.

The Photocatalytic Performance of Nd2O3 Doped CuO Nanoparticles with Enhanced Methylene Blue Degradation: Synthesis, Characterization and Comparative Study

The growth of the textile industry results in a massive accumulation of dyes on water. This enormous rise in pigments is the primary source of water pollution, affecting the aquatic lives and our ecosystem balance. This study aims to notify the fabrication of neodymium incorporated copper oxide (Nd2O3 doped CuO) nanoparticles by combustion method for effective degradation of dye, methylene blue (MB). X-ray diffraction (XRD), Field emission Scanning electron microscopy (FESEM), Zeta potential have been applied for characterization. Photocatalyst validity has been evaluated for methylene blue degradation (MB). Test conditions such as time of contact, H2O2, pH, and photo-Fenton have been modified to identify optimal degradation conditions. Noticeably, 7.5% Nd2O3 doped CuO nanoparticle demonstrated the highest photocatalytic efficiency, up to 90.8% in 80 min, with a 0.0227 min-1 degradation rate. However, the photocatalytic efficiency at pH 10 becomes 99% with a rate constant of 0.082 min-1. Cyclic experiments showed the Nd2O3 doped CuO nanoparticle's stability over repeated use. Scavenge hydroxyl radical species responsible for degradation using 7.5% Nd2O3 doped CuO nanoparticles have been investigated under visible irradiation.

Flexible photocatalytic membrane based on CdS/PMMA polymeric nanocomposite films: multifunctional materials

In this study, poly(methyl methacrylate) with different doping nano-cadmium sulfide (CdS/PMMA) is prepared and characterized. CdS/PMMA polymeric nanocomposite films were synthesized using solution casting methodology. SEM and XRD are used for structure analysis for the studied nanocomposite films. XRD revealed the amorphous domains of PMMA polymer, which increased with increasing CdS nanoparticle contents. SEM revealed the CdS dispersion within the PMMA matrix. CdS nanoparticles in the PMMA matrix are expected to be aggregated due to the casting technique. The optical energy gap is found to be decreased after the CdS addition. ε' and ε″ have the same behavior with the applied frequency. Maxwell-Wagner interfacial polarization is the responsible factor for higher values of ε'-ε″ at the higher frequencies. Electrical conductivity behavior σ_AC tends to obtain a constant value at lower frequencies that approach from its DC conductivity values. After doping PMMA with nano-CdS, an exponential increase after a critical frequency value and the values of σ_AC was also increased. Besides, a significant reduction in laser energy power is identified by the reduction of the output power. CdS/PMMA can attenuate the laser power due to its nonlinear effect. CdS/PMMA nanocomposite can act as a photocatalyst to improve the performance of the photodegradation of Rhodamine B (RhB). Among the different CdS/PMMA nanocomposite films, 3.33 wt% CdS/PMMA demonstrates the highest efficiency in visible photocatalysis of Rhodamine B. CdS/PMMA can be utilized as multifunctional materials use like laser optical limiting to reduce the power of laser sources and as a photocatalyst membranes.

Application of solid waste of ductile cast iron industry for treatment of wastewater contaminated by reactive blue dye via appropriate nano-porous magnesium oxide

The solid waste of ductile iron industry, which contains at least 88.0% magnesium oxide, is one of the toxic materials, leading to land contamination. On the other hand, the removal of reactive dyes from wastewaters is difficult required effective adsorbent like nano-porous MgO. The novelty of present investigation is based on nano-porous magnesium oxide production by precipitation from the solid waste to treat the wastewaters contaminated by reactive dye which is abundantly used in the textile industry. In order to improve the adsorptive properties of extracted MgO powder, the combinations of surfactants, containing cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS) and polyoxyethylene octyl phenyl ether (TX100) were applied based on the mixture design algorithm in the precipitation. The effects of processing factors such as surfactant composition, powder calcination temperature, surfactant dose and pH were evaluated on the removal efficiency. The results revolved that the combination of SDS and TX100, 1:1, plays an effective role in the production of particles with the appropriate average pore size, 16 nm. The adsorbent prepared in the optimum condition indicated a significant affinity for the removal of reactive dye which shows relatively pH-independent efficiency in the range of 3-9. The applied producer for fabrication of adsorbent eventually overcomes the pH-dependent problem for the toxic dye uptake, leading to produce the adsorbent with maximal adsorption capacity of 1000 mg g^-1.

Synthesis of Bi2WO6/Na-bentonite composites for photocatalytic oxidation of arsenic(iii) under simulated sunlight

Novel Bi₂WO₆/bentonite (denoted as BWO/BENT) composites were prepared via a typical hydrothermal process and employed for the photocatalytic oxidation of arsenic(iii) (As(iii)). The properties of the prepared samples were characterized through X-ray diffraction, transmission and scanning electron microscopy, UV-visible diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, and photoluminescence spectroscopy. Effects of the BENT ratio on the As(iii) removal were explored under simulated sunlight, and the best photocatalytic effect was observed for the composite with BWO : BENT = 7 : 3 w/w. Compared with the pure BWO, the BWO/BENT composites exhibited an improved photocatalytic ability in the removal of As(iii), which was mainly ascribed to the enlarged specific surface area and the suppressed electron–hole recombination by the incorporated BENT. Furthermore, photo-generated holes (h⁺) and superoxide radicals ·O₂⁻ were confirmed to be the major contributors to the oxidation of As(iii), and an associated mechanism of photocatalytic oxidation of As(iii) over BWO/BENT composites was proposed.

Novel Bi₂WO₆/bentonite (denoted as BWO/BENT) composites were prepared via a typical hydrothermal process and employed for the photocatalytic oxidation of arsenic(iii) (As(iii)).