Synthesis of flower-like MoS2/CNTs nanocomposite as an efficient catalyst for the sonocatalytic degradation of hydroxychloroquine

Sustainable Natural Deep Eutectic Solvent-Mediated Synthesis of Magnesium Zirconate Nanoparticles: A Photocatalyst for the Degradation of Anti-Viral Drug

The anti-viral drug hydroxychloroquine (HCQ) has captivated significant interest in the pharmaceutical field, as it is a quinolone derivative. Its unrestrained occurrence causes prominent health hazards owing to its persistent, carcinogenic, recalcitrant, and teratogenic nature. Herein, in this work, an experimental investigation was carried out toward the photocatalytic degradation of HCQ drug using magnesium zirconate (MgZrO3) nanoparticles as an effective photocatalyst. A comprehensive characterizations of the as-synthesized material was carried out. The photocatalytic degradation of the HCQ drug was examined with various sources of light energies. The obtained outcomes indicated that ±85% of HCQ was degraded using a MgZrO3 photocatalyst within 30 min of the reaction time under UV-visible (ultraviolet) light irradiation. Further, other significant operational parameters such as various catalyst dosages, HCQ concentrations, pH, scavengers, and salts were examined. The degradation studies revealed that the reaction followed pseudo-first-order kinetics. Hence, this perovskite-type MgZrO3 has grasped profound attention in environmental remediation, significantly in photocatalytic degradation of HCQ drug. This comprehensive research offers green synthesis strategy as a substantial framework for providing effective photocatalyst that addresses contemporary water pollution issues linked to notable results. This aids in targeting era-driven advancements toward a clean and safe future environment.

Continuous ultrasonic ozone coupling technology-assisted control of ceramic membrane fouling coupled enhanced multiphase mixing to treat dye wastewater and CFD flow field simulation

In this study, ozone catalysts (hydrogenation-modified red mud, HM-RM) successfully prepared by hydrogenation-modification of industrial hazardous solid waste red mud (RM) as a raw material in accordance with the viewpoint of treating waste with waste and using waste. Meanwhile, as for the common phenomenon of membrane fouling, uneven distribution of multiphase solid catalysts and ozone in liquids, the addition of ultrasound can not only disperse materials, but also play a role in online cleaning of ceramic membranes and catalysts. The optimum treatment conditions for Rhodamine B (RhB) solution with volume of 2 L and concentration of 40 mg/L were catalyst concentration of 0.4 mg/L, reaction temperature of 45 °C, ultrasonic time of 1 h, ultrasonic intensity of 600 W, removal rate of RhB was up to 90 %. In addition, the computational fluid dynamics (CFD) simulation method was used to investigate the fluid flow between the two gas-liquid phases and the effect of the negative pressure of the membrane pump on the fluid by the analysis of flow, pressure and ozone flux of the ceramic membrane(CM) reaction apparatus. The CFD simulation results showed that at the inlet gas-liquid flow rate of 3 m/s and the negative pressure of 20,000 Pa, the maximum flow rates of CM-1 were 3 m/s, 0.752 m/s for CM-2, and 0.228 m/s for CM-3, respectively. Vortices, which are beneficial to solid-liquid mixing and gas-liquid mass transfer, formed between the suction port CM-1 of CM-1 and the inlets of CM-2 and CM-3. This discovery is consistent with relevant experimental research results. Significantly higher concentrations of both •OH and dissolved ozone were observed in the US/HM-RM/O3 system compared to other systems, indicating the significant improvement in ozone utilization rate through the application of ultrasound. The superiority of the US/HM-RM/O3 device was demonstrated. The real dye effluent was tested under optimum operating conditions and the results showed that COD and TOC were reduced by 81.34 % and 60.23 % respectively after 180 min of treatment. The above research can provide technical support for the treatment of dye wastewater using Ultrasound-enhanced ozone oxidation ceramic membranes.

A Box-Behnken design-based chemometric approach to optimize the sono-photodegradation of hydroxychloroquine in water media using the Fe(0)/S2O82-/UV system

The huge utilization of hydroxychloroquine in autoimmune infections led to an abnormal increment in its concentration in wastewater, which can pose a real risk to the environment, necessitating the development of a pretreatment technique. To do this, we are interested in researching how hydroxychloroquine degrades in contaminated water. The main goal of this investigation is to optimize the operating conditions for the sono-photodegradation of hydroxychloroquine in water using an ultrasound-assisted Fe(0)/S 2 O 8 2 - /UV system. To get adequate removal of HCQ, a chemometric method based on the Box-Behnken design was applied to optimize the influence of the empirical parameters selected, including Fe(0) dose,S 2 O 8 2 - concentration, pH, and initial HCQ concentration. The quadratic regression model representing the HCQ removal rate (η(%)) was evolved and validated by ANOVA. The optimal conditions as a result of the above-mentioned trade-off between the four input variables, with η(%) as the dependent output variable, were captured using RSM methodology and the composite desirability function approach. For HCQ full decomposition, the optimal values of the operating factors are as follows:S 2 O 8 2 - dose, 194.309 mg/L; Fe(0) quantity, 198.83 mg/L; pH = 2.017, and HCQ initial dose of 296.406 mg/L. Under these conditions, the HCQ removal rate, achieved after 60 min of reaction, attained 98.95%.

Recyclable MXene-bridged Z-scheme NiFe2O4/MXene/Bi2WO6 heterojunction with enhanced charge separation for efficient sonocatalytic removal of ciprofloxacin

Sonocatalysis has emerged as a promising technology for addressing environmental pollution issues. However, the efficacy of sonocatalytic processes is primarily hindered by challenges related to the sluggish flow rate of photogenerated electrons. This study presents a novel approach to address this issue by developing an improved Z-scheme NiFe2O4/MXene/Bi2WO6 (NMB) composite that exhibits exceptional sonocatalytic activity for ciprofloxacin (CIP) degradation. In particular, the NiFe2O4/MXene (5 wt%)/Bi2WO6 composite could achieve high CIP (at 10 mg/L) degradation efficiency (97.39 %) after 60 min of ultrasonic irradiation. The exceptional sonocatalytic activity of the composite was attributed to the synergistic interaction of the Z-scheme heterojunction charge transfer route and the electron mediator of Ti3C2-MXene, which enhances light collection capacity, separates photogenerated carriers efficiently, and improves redox activity of the composite. The scavenging experiments reveal that the sonocatalytic degradation of CIP was driven by holes (h+), hydroxyl radicals (•OH), and superoxide anion radicals (•O2-), with the former playing a dominant role. The results of reuse experiments demonstrate the outstanding sonocatalytic stability of the catalyst, as well as its uncomplicated recovery. The developed NMB Z-scheme composite shows promise for sonocatalytic treatment of antibiotics in industrial wastewaters, particularly those with high turbidity and/or low transparency. The findings also open up avenues for developing efficient and cost-effective sonocatalysts with good recyclability and remarkable performance.

Boosting the sonophotocatalytic performance of BiOCl by Eu doping: DFT and an experimental study

Bismuth oxychloride (BiOCl) has a unique layered structure and uneven charge distribution, resulting in an internal electric field under polarization, which promotes the efficient separation and migration of photogenerated carriers. BiOCl could be a candidate for sonophotocatalysts. However, the low utilization of visible light limits the application of BiOCl in photocatalysts. In this study, the photocatalytic performance of rare earth element (Nd, Sm, Eu, Er and Er)-doped BiOCl was studied by density functional theory (DFT) and experimentally to screen high-performance catalysts. The band structure, density of states, and optical properties were calculated by the DFT method to predict the photocatalytic activity of rare earth-doped BiOCl. The built-in electric field formed in Eu-doped BiOCl inhibiting electron and hole recombination can be observed. Subsequently, the activity of the photocatalyst and sonophotocatalysts was evaluated. The results show that the photocatalytic and sonophotocatalytic activity of Eu-doped BiOCl is improved, which is consistent with the theoretical prediction. Combining theoretical calculations with experiments, the sonophotocatalytic activity of Eu-doped BiOCl is enhanced, mainly due to the synergistic effect of inhibiting carrier recombination, and expansion to the visible light absorption region.

One-step chemically vapor deposited hybrid 1T-MoS2/2H-MoS2 heterostructures towards methylene blue photodegradation

The photocatalytic degradation of methylene blue is a straightforward and cost-effective solution for water decontamination. Although many materials have been reported so far for this purpose, the proposed solutions inflicted high fabrication costs and low efficiencies. Here, we report on the synthesis of tetragonal (1T) and hexagonal (2H) mixed molybdenum disulfide (MoS2) heterostructures for an improved photocatalytic degradation efficiency by means of a single-step chemical vapor deposition (CVD) technique. We demonstrate that the 1T-MoS2/2H-MoS2 heterostructures exhibited a narrow bandgap ∼ 1.7 eV, and a very low reflectance (<5%) under visible-light, owing to their particular vertical micro-flower-like structure. We exfoliated the CVD-synthesised 1T-MoS2/2H-MoS2 films to assess their photodegradation properties towards the standard methylene blue dye. Our results showed that the photo-degradation rate-constant of the 1T-MoS2/2H-MoS2 heterostructures is much greater under UV excitation (i.e., 12.5 × 10-3 min-1) than under visible light illumination (i.e., 9.2 × 10-3 min-1). Our findings suggested that the intermixing of the conductive 1T-MoS2 with the semi-conducting 2H-MoS2 phases favors the photogeneration of electron-hole pairs. More importantly, it promotes a higher efficient charge transfer, which accelerates the methylene blue photodegradation process.

Fe3O4@MIL-100(Fe) modified ZnS nanoparticles with enhanced sonocatalytic degradation of tetracycline antibiotic in water

Sonocatalysis has attracted excellent research attention to eradicate hazardous pollutants from the environment effectively. This work synthesised an organic/inorganic hybrid composite catalyst by coupling Fe3O4@MIL-100(Fe) (FM) with ZnS nanoparticles using the solvothermal evaporation method. Remarkably, the composite material delivered significantly enhanced sonocatalytic efficiency for removing tetracycline (TC) antibiotics in the presence of H2O2 compared to bare ZnS nanoparticles. By adjusting different parameters such as TC concentration, catalyst dosage and H2O2 amount, the optimized composite (20 %Fe3O4@MIL-100(Fe)/ZnS) removed 78.25% antibiotic in 20 min at the cost of 1 mL of H2O2. These much superior activities are attributed to the efficient interface contact, effective charge transfer, accelerated transport capabilities and strong redox potential for the superior acoustic catalytic performance of FM/ZnS composite systems. Based on various characterization, free radical capture experiments and energy band structures, we proposed a mechanism for the sonocatalytic degradation of tetracycline based on S-scheme heterojunctions and Fenton like reactions. This work will provide an important reference for developing ZnS-based nanomaterials to study sonodegradation of pollutants.

Sonocatalytic degradation of tetracycline hydrochloride with CoFe2O4/g-C3N4 composite

In this work, different mass percent ratios of CoFe₂O₄ coupled g-C₃N₄ (w%-CoFe₂O₄/g-C₃N₄, CFO/CN) nanocomposites were integrated through a hydrothermal process for the sonocatalytic eradication of tetracycline hydrochloride (TCH) from aqueous media. The prepared sonocatalysts were subjected to various techniques to investigate their morphology, crystallinity, ultrasound wave capturing activity and charge conductivity. From the investigated activity of the composite materials, it has been registered that the best sonocatalytic degradation efficiency of 26.71 % in 10 min was delivered when the amount of CoFe₂O₄ was 25% in the nanocomposite. The delivered efficiency was higher than that of bare CoFe₂O₄ and g-C₃N₄. This enriched sonocatalytic efficiency was credited to the accelerated charge transfer and separation of e^--h⁺ pair through the S-scheme heterojunctional interface. The trapping experiments confirmed that all the three species i.e. ^•OH, h⁺ and ^•O₂^- were involved in the eradication of antibiotics. A strong interaction was shown up between CoFe₂O₄ and g-C₃N₄ in the FTIR study to support charge transfer as confirmed from the photoluminescence and photocurrent analysis of the samples. This work will provide an easy approach for fabricating highly efficient low-cost magnetic sonocatalysts for the eradication of hazardous materials present in our environment.

Catalytic activation of hydrogen peroxide by Cr2AlC MAX phase under ultrasound waves for a treatment of water contaminated with organic pollutants

This study aims to investigate the sonocatalytic activation of hydrogen peroxide (H2O2) using Cr2AlC MAX phase prepared by the reactive sintering process. The hexagonal structure of the crystalline MAX phase was confirmed by X-ray diffraction. Moreover, the compacted layered structure of the MAX phase was observed via scanning electron microscopy and high-resolution transmission electron microscopy. Under the desired operating conditions, Cr2AlC MAX phase (0.75 g/L) showed suitable potential to activate H2O2 (1 mmol/L) under sonication, thereby allowing a considerable removal efficiency for various organic pollutants, including dimethyl phthalate (69.1%), rifampin (94.5%), hydroxychloroquine (100%), and acid blue 7 (91.5%) with initial concentration of 15 mg/L within 120 min of treatment. Kinetic analysis proved that the degradation reaction followed pseudo-first-order kinetics. Scavenging tests demonstrated that hydroxyl radicals and singlet oxygen were effective species during degradation. Furthermore, a probable mechanism for dimethyl phthalate degradation was suggested according to gas chromatography-mass spectroscopy and nuclear magnetic resonance analyses. The obtained results confirmed the capability of the triple Cr2AlC/H2O2/US process as a promising method for treating contaminated water.

Titanium-based MAX-phase with sonocatalytic activity for degradation of oxytetracycline antibiotic

In light of growing environmental concerns over emerging contaminants in aquatic environments, antibiotics in particular, have prompted the development of a new generation of effective sonocatalytic systems. In this study, a new type of nano-laminated material, Ti₂SnC MAX phase, is prepared, characterized, and evaluated for the sonocatalytic degradation of oxytetracycline (OTC) antibiotic. A variety of identification analyses, including X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectrometry, Brunauer-Emmett-Teller, and diffuse reflectance spectroscopy, were conducted to determine the physicochemical properties of the synthesized catalyst. By optimizing the operating factors, total degradation of OTC occurs within 120 min with 1 g L^-1 catalyst, 10 mg L^-1 OTC, at natural pH of 7.1 and 150 W ultrasonic power. The scavenger studies conclude that the singlet oxygen and superoxide ions are the most active species during the sonocatalytic reaction. Based on the obtained data and GC-MS analysis, a possible sonocatalytic mechanism for the OTC degradation in the presence of Ti₂SnC is proposed. The catalyst reusability within eight consecutive runs reveals the proper stability of Ti₂SnC MAX phase. The results indicate the prospect for MAX phase-based materials to be developed as efficient sonocatalysts in the treatment of antibiotics, suggesting a bright future for the field.