Novel MgFe2O4-CuO/GO heterojunction magnetic nanocomposite: Synthesis, characterization, and batch photocatalytic degradation of methylene blue dye

Synthesis, characterization, and application of MnFe2O4/FeVO4/modified zeolite nanocomposite as an effective photocatalyst for methylene blue degradation and benzothiophene desulfurization

This study details the synthesis of a novel ternary nanocomposite composed of MnFe2O4, FeVO4, and modified zeolite, achieved through a two-step process. The initial step involved the hydrothermal synthesis of the MnFe2O4/FeVO4 composite, followed by its application onto modified zeolite using ultrasonic waves. The synthesized nanocomposite was thoroughly characterized using a range of analytical techniques. X-ray diffraction (XRD) analysis indeed confirmed the successful synthesis of MnFe2O4/FeVO4 composite without impurities and other by-products. This purity was significantly facilitated by the inclusion of hydrazine during the synthesis process. Field emission scanning electron microscopy (FESEM) provided insights into the morphology, indicating that the use of hydrazine resulted in smaller particle sizes and reduced agglomeration. Energy dispersive spectroscopy (EDS) mapping demonstrated a uniform distribution of the particles on the modified zeolite, while transmission electron microscopy (TEM) images revealed spherical particle shapes and the layered structure of the zeolite. Diffusion reflectance spectroscopy (DRS) analysis indicated bandgap values of 1.38 eV for MnFe2O4 /FeVO4, 1.48 eV for the 1:1 ratio of MnFe2O4 /FeVO4/modified zeolite, and 1.44 eV for the 2:1 ratio. In terms of pollutant degradation, the study evaluated the removal efficiency of methylene blue (MB) across various samples, with the following removal percentages: MnO2/MnFe2O4 (66 %), FeO2/Fe0.5V3.5O8 (60 %), MnFe2O4 /FeVO4 (67 %), amorphous (58 %), MnFeO3/Fe2VO4/Mn2V2O7 (64 %), MnFe2O4 /FeVO4/modified zeolite (1:1) (84 %), and MnFe2O4 /FeVO4/modified zeolite (2:1) (93 %). For sulfur removal, the efficiencies were recorded as 67 %, 28 %, 68 %, 45 %, 22 %, 83 %, and 100 % for the same samples, respectively. This comprehensive characterization and evaluation of pollutant removal efficiencies highlight the potential applications of the synthesized nanocomposite in environmental remediation.

Simultaneous optimization of production yield and sulfadiazine adsorption of MgFe2O4 loaded on prickly pear biochars using Box-Behnken design

A major challenge that humans facing is the uncontrolled discharge of antibiotic-containing wastewater into the environment, accompanying with huge threats to human community. The utilization of cost-effective biomass-based adsorbents is considered a potential solution for the treatment of antibiotic wastewater. This study aims to optimize the synthesis of MgFe2O4 nanoparticles loaded on prickly pear biochar (PPB) with outstanding sulfadiazine adsorbability using response surface methodology. Thirteen materials (MgFe2O4-PPB) produced based on Box-Behnken design were tested to evaluate the impact of the main factors on the material preparation process, including ratio of MgFe2O4:PPB precursors, calcination temperature and calcination time. Under optimized conditions, i.e., MgFe2O4:PPB ratio 0.5, temperature 600 °C and time 1 h, the production yield of 46.5% and sulfadiazine removal percentage of 85.4% were obtained. Characterization of optimized MgFe2O4-PPB indicated the good porosity and functionality suitable for the adsorption of sulfadiazine. Elovich model showed the best description of kinetic process. Temkin model was considered to be an accurate description of the isotherm adsorption. Proposed mechanism for antibiotic adsorption onto MgFe2O4-PPB was described. We clarify cost-benefit analysis to asses the importance of MgFe2O4-PPB as well as the economic and environmental impacts of biochar-based composites.

Application of Photocatalysis and Sonocatalysis for Treatment of Organic Dye Wastewater and the Synergistic Effect of Ultrasound and Light

Organic dyes play vital roles in the textile industry, while the discharge of organic dye wastewater in the production and utilization of dyes has caused significant damage to the aquatic ecosystem. This review aims to summarize the mechanisms of photocatalysis, sonocatalysis, and sonophotocatalysis in the treatment of organic dye wastewater and the recent advances in catalyst development, with a focus on the synergistic effect of ultrasound and light in the catalytic degradation of organic dyes. The performance of TiO₂-based catalysts for organic dye degradation in photocatalytic, sonocatalytic, and sonophotocatalytic systems is compared. With significant synergistic effect of ultrasound and light, sonophotocatalysis generally performs much better than sonocatalysis or photocatalysis alone in pollutant degradation, yet it has a much higher energy requirement. Future research directions are proposed to expand the fundamental knowledge on the sonophotocatalysis process and to enhance its practical application in degrading organic dyes in wastewater.

Synthesis and characterization of titanium-substituted nanocrystalline Co2-Y hexaferrite: magnetically retrievable photocatalyst for treatment of methyl orange contaminated wastewater

Rapid industrial growth causes considerable environmental havoc, adversely affecting human and aqueous life. It becomes a significant concern to deal with adequate wastewater treatment strategies by converging on water scarcity. This research work explored the synthesis of titanium-substituted Y-type barium hexaferrite (Co₂-Y), having a general formula of Ba₂Co₂Fe_12-xTi_xO₂₂ (x = 0.0, 0.1, 0.2, 0.3, 0.4, and 0.5), using a facile nitrate-based sol-gel auto-combustion route and its suitability was investigated as a heterogeneous catalyst within the photo-Fenton-based degradation of methyl orange (MO), one of the significant pollutants generated from textile industries. Developing a thermochemically stable and magnetically separable heterogeneous catalyst for photocatalytic decomposition of nonbiodegradable organic dye from wastewater was also emphasized. The as-prepared nanocrystalline Co₂-Y powders were analyzed using XRD, FTIR, DLS, UV-visible spectroscopy, SEM, VSM, and XPS. Furthermore, the photocatalytic degradation performance of pristine and titanium substituted Ba₂Co₂Fe_11.6Ti_0.4O₂₂ ferrite, having the lowest bandgap value among all samples, was quantified and compared in terms of apparent rate constant (k_arc) value and turnover frequency values. The enriched photocatalytic performance was correlated with the existence of multi-valance states of transition metal cations and the availability of oxygen vacancy, confirmed by the surface chemistry using the XPS analysis. The modified (enhanced thermal and chemical stability) hexaferrite catalyst was magnetically separable and reusable without significant losses to its catalytic performance. This promising catalyst may be considered as a replacement for soft ferrite materials to catalyze the degradation of several other nonbiodegradable organic pollutants from wastewater in large-scale industries.