Sonophotocatalytic Process Research Articles

Electrophoretic-deposited Fe-doped TiO2 nanofilm via a one-pot, in-situ process with enhanced sonophotocatalytic performance in amoxicillin antibiotic removal

In this study, Fe-doped TiO2 nanofilm was fabricated using a solvothermal method and subsequently applied to the substrate via an electrophoretic deposition (EPD) technique without requiring a binding agent. The aim of this research is to enhance the sonophotocatalytic performance of TiO2 by integrating iron impurities into the catalyst structure, thereby addressing the limitation of the catalyst's inactivity under visible light and tackling the issue of catalyst separation for reuse. This method guarantees that the nanofilm is deposited uniformly and under regulated conditions on the substrate. X-ray diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive X-ray (EDX) analysis, Fourier transform infrared spectroscopy (FTIR), and UV-Vis techniques were employed to characterize the synthesized nanofilms. The findings indicate that the resulting nanofilms were responsive to visible light and exhibited high efficiency in the degradation of amoxicillin (AMX). The sonophotocatalytic process eliminated approximately 90% of the amoxicillin, while ultrasound alone could degrade 17% and visible light alone could degrade about 39%. It was calculated and noted that the combination of ultrasonic and visible light had a synergistic effect of roughly 70.7%. The most notable discovery was that the nanofilm could degrade 83% of AMX after four applications, demonstrating its reusability.

Efficient Degradation of Methyl Violet 10B Dye by Different Light Sources using Boron-doped TiO2-ZnO Photocatalyst

Boron-doped TiO2-ZnO nanocomposite was prepared by sonochemically using boron trichloride, tetra n-butyl orthotitanate and zinc acetate in appropriate proportion. The as-prepared nanocomposite was successfully characterized by XRD, EDX, SEM and BET techniques The operational factors that affect the rate of photocatalytic degradation of methyl violet 10B present in wastewater were optimized, which include initial dye concentration, catalyst amount, pH level and different light intensities such as incandescent light bulb, UV lamp and sunlight. During sonication under sunlight, it was found that the most effective removal rate achieved was 95% when using 0.02 g of B doped TiO2-ZnO per 100 mL of methyl violet 10B solution. The impact of different dye concentrations on the photocatalytic degradation demonstrated the threshold at which concentrations may be readily eliminated. The most effective pollutant degradation was achieved at 5 ppm. The introduction of oxygen using sonophotocatalysis process into the polluted stream enhanced the photocatalytic breakdown of the pollutants. The photocatalyst can be recycled for four cycles without loss the catalyst stability and the degradation rate obeys first-order kinetics.

Effective sonophotocatalytic degradation of tetracycline in water: Optimization, kinetic modeling, and degradation pathways

Hybrid advanced oxidation processes (AOPs) are gaining interest in degradation of variety of recalcitrant compounds for water and wastewater treatment, due to possible synergistic effects. The present study systematically evaluated the degradation of tetracycline (TC) with a sonophotocatalytic process combining acoustic cavitation (sonocavitation) and photocatalysis based on N-doped TiO2 catalyst. The TC degradation rate constant was 2.4 × 10−2 min−1, i.e., much higher than individual sonocatalytic (0.5 × 10−2 min−1) and photocatalysis (0.6 × 10−2 min−1) processes at the optimized conditions. The synergy index was 2.14, which reveals a significant improvement in the process performance. Maximum TC degradations of 55.5 ± 1.8 % for photocatalysis, 66.4 ± 1.8 % for sonocatalysis, and 79.5 ± 0.3 % for sonophotocatalysis were observed for 10 mg L−1 initial TC concentration after 90 min of treatment. The photocatalytic experiments were extended further to 210 min to achieve a maximum degradation of 78.9 ± 0.2 % at the optimized condition. Scavenging experiments confirmed that hydroxyl radicals (•OH), electron holes (h+), and superoxide radical anions (O2−•) played a significant role in the degradation of TC. Further, the degradation intermediates for each process were identified and degradation pathways were proposed. Empirical kinetic models based on operational parameters were also developed and validated.

Performance of UV/TiO2/PS, US/TiO2/PS and UV/US/TiO2/PS processes on the diazinon degradation from aqueous solutions and toxicity assay

Diazinon is a highly dangerous organophosphorus pesticide that conventional treatment methods cannot remove from wastewater. This study aims to investigate ultrasound-chemical-photocatalysis as an eco-friendly method for the effective decomposition of diazinon. The combination of ultrasound and ultraviolet leads to the formation of higher oxidizer agents and faster diazinon decomposition. To assess the efficiency of processes, experiments with AOP based on ultrasound, AOP based on ultraviolet, and a sonophotocatalytic process were conducted. The experiments were done in a glass photoreactor equipped with a UVC lamp and an ultrasonic device. The residual diazinon and intermediates were read by GC-MS. The results indicate that the highest degradation in all processes occurred at Time = 30 min, PS = 3 mmol, and pH = 3. Notably, the sonophotocatalyst process required the lowest catalyst usage. Since the efficiency of photocatalytic processes is significantly influenced by the amount and rate of generation of strong oxidizer radicals; consequently, the highest efficiency was observed in the UV/US/TiO2/PS process. Moreover, the electric energy consumption followed the order US/TiO2/PS> UV/US/TiO2/PS > UV/TiO2/PS. Additionally, with ATU < 1, the toxicity of the wastewater to the environment was found to be low.

Sono-photocatalytic degradation of Tetracycline and Ciprofloxacin antibiotics using microwave-reflux of NiO-MoS2/rGO ternary nanocomposite

In this study, NiO-MoS2/rGO nanocomposites were synthesized successfully by a simple microwave assisted refluxing method by varying the mass ratios of rGO. The NiMG-50 ternary nanocomposite has been applied by sonocatalytic, photocatalytic and sono-photocatalytic degradation for the removal of tetracycline (TTC) and ciprofloxacin (CIP) antibiotics. Physicochemical properties of the synthesized samples were characterized by Powder X-ray Diffraction (PXRD), Energy Dispersive X-ray Spectroscopy (EDAX) and X-ray Photoelectron Spectroscopy (XPS) corroborated the phase purity of NiMG-50 nanocomposite. The High Resolution Scanning Electron Microscopy (HR-SEM) image reveals the zigzag arrangements of NiO nanoflakes over MoS2 and rGO sheets. The tight contact of platelet shaped-NiO NP’s and curled layer-MoS2 on the sheets of rGO results in the separation of photo-induced e--h+ pairs as demonstrated by the High Resolution Transmission Electron Microscopy (HR-TEM) analysis. Optical properties reveal a reduced band gap and enhanced separation efficiency with fast charge transfer rate, improving the organic pollutant degradation efficiency. NiMG-50 demonstrated a good catalytic activity against TTC and CIP in sono-photocatalytic process with an efficiency of 94.10 % and 83.96 % at 35 and 90 min, respectively. Simultaneously, the experimental results showed that the NiMG-50 composite follows the pseudo-first order reaction kinetics with a rate constant (KSP) value of 0.077 min−1 and 0.015 min−1 for TTC and CIP. The radical trapping test and degradation mechanism indicated that the continuous contribution of ̇OH and ̇O2– reactive radicals are the major ones responsible for the active involvement in the degradation reaction. This research work gives a fresh prospects to the as prepared NiMG catalyst as an efficient composite with a good applicability for the sono-photocatalytic degradation of pharmaceutical products.

Synergistic effect of Sonophotocatalytic degradation of crystal violet and alizarin red S dyes using Ag-doped ZnSnO3 nanoparticles

This study proposes an environmentally conventional sonophotocatalytic method that uses silver (Ag)-doped ZnSnO3 nanoparticles (NPs) to effectively eliminate industrial dye-polluted wastewater. This study was conducted to investigate the effect of the Ag doping ratio of the synthesized ZnSnO3 NPs on the removal of dye molecules. We used crystal violet (CV) and alizarin red S (AR) dyes as test pollutants to examine the catalytic activity of the synthesized Ag-doped ZnSnO3 NPs in response to the ultrasound and visible light stimulation. The most effective photocatalytic performance was exhibited by 4 % Ag-ZnSnO3 NPs, which degraded 95 % of the CV and 52 % of the AR dye in 100 min. Surprisingly, using sonophotodegradation to combine ultrasound with visible-light irradiation has resulted in almost complete degradation of the CV dye in 100 min, demonstrating a strong beneficial synergy between the sonocatalytic and photocatalytic processes. Additionally, the sonophotocatalytic degradation of the CV and AR dyes was examined at various pH values. It shows to have high stability across several cycles of dye treatment, indicating that this method can be used for industrial effluents. Scavenger tests demonstrated that the primary active species in the dye degradation is O2•−. Ultimately, the prepared Ag-ZnSnO3 NPs and sonophotocatalytic processes may offer a promising path toward a variety of environmental uses, including the remediation of water and the removal of other organic contaminants.

Modified metal–organic frameworks for sonophotocatalytic elimination of wastewater pollutants

In recent decades, people have witnessed a rapid development of society, accompanied by the increase sharply of numerous organic/inorganic contaminants from industrial effluents. The high toxicity of pollutants has led to long‐term risk to human health. To connect with environment‐friendly green chemistry and sustainable development, photocatalysis technology has emerged. Metal–organic framework (MOF)‐based photocatalysts performed high efficiency for the elimination of wastewater pollutants. Nevertheless, the large band gap energy and high recombination rate of photogenerated electron–hole pair decrease the catalytic efficiency. Sonochemistry is regarded as a safe, highly efficient, clean, and eco‐friendly technology, which has aroused a lot of interest in the treatment of wastewater. The cavitation effect induced by ultrasonic waves promotes the generation of additional active radicals. The ultrasonic oscillation facilitates cleaning the surface of catalysts, dispersing catalyst particles, and increasing proton transport. Therefore, photocatalysis coupling with ultrasonic waves, known as sonophotocatalysis (SPC), is a promising means for enhancing the overall performance of wastewater treatments. This review discusses the recent advancements of hybrid MOF‐based photocatalysts driving the wastewater treatments in SPC system. The catalytic performance of hybrid MOF is discussed in the SPC process. The inner properties of phases in hybrid MOF such as the location of redox potential and transfer direction of electrons and energy after hybridization are elucidated. Additionally, the review discusses the existing challenges and obstacles of MOF‐based SPC system and proposes feasible improvements to meet the future requirements of practical applications.

Semiconductor Catalyst: Investigation for the Degradation of BB9 Azo Dye by Sonophotocatalytic Process

AbstractThe degradability of an azo dye, Basic Blue 9 (BB9), by heterogeneous sonocatalytic, photocatalytic, and sonophotocatalytic oxidation process was examined using simultaneous irradiation of UV‐C at 254 nm and power ultrasound at 20 kHz accompanied with a heterogeneous catalyst zinc oxide (ZnO) in the study. The effect of ZnO dose and initial dye concentration was investigated on the dye degradation in sonocatalytic, photocatalytic, and sonophotocatalytic processes at pH 5.5 (natural pH). The results obtained from the experimental studies were evaluated with the parameters of color removal, pseudo‐first‐order rate constant, and half‐life time. It was observed that the degradation of BB9 dye by the sonophotocatalytic process was higher compared to both sonocatalytic and photocatalytic degradation. as follows: 97.46, 48.64 and 56.88 %. The combination of sono and photocatalytic showed a remarkable synergistic effect in BB9 degradation. The kinetics of sonophotocatalytic oxidations, depending on the initial BB9 dye concentration, were found to follow the Langmuir‐Hinshelwood model. In addition, the effect of ZnO on the sonophotocatalytic oxidation process was higher compared to titanium dioxide and zero‐valent iron as follows: 97.47, 80.77 and 80.62 %.

Sonophotocatalytic removal of organic dyes in real water environments using reusable BiSI@PVDF-HFP nanocomposite membranes

Focusing on the uncontrolled discharge of organic dyes, a known threat to human health and aquatic ecosystems, this work employs a dual-functional catalyst approach, by immobilizing a synthesized bismuth sulfur iodide (BiSI) into a poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) polymeric matrix for multifunctional water remediation. The resulting BiSI@PVDF nanocomposite membrane (NCM), with 20 wt% filler content, maintains a highly porous structure without compromising morphology or thermal properties. Demonstrating efficiency in natural pH conditions, the NCM removes nearly all Rhodamine B (RhB) within 1 h, using a combined sonophotocatalytic process. Langmuir and pseudo-second-order models describe the remediation process, achieving a maximum removal capacity (Qmax) of 72.2 mg/g. In addition, the combined sonophotocatalysis achieved a degradation rate ten and five times higher (0.026 min−1) than photocatalysis (0.002 min−1) and sonocatalysis (0.010 min−1). Furthermore, the NCM exhibits notable reusability over five cycles without efficiency losses and efficiencies always higher than 90%, highlighting its potential for real water matrices. The study underscores the suitability of BiSI@PVDF as a dual-functional catalyst for organic dye degradation, showcasing synergistic adsorption, photocatalysis, and sonocatalysis for water remediation.

Simultaneous degradation of methyl orange and indigo carmine dyes from an aqueous solution using nanostructured WO3 and CuO supported on Zeolite 4A

In this study, a novel composite catalyst system, Zeolite 4A/WO3/CuO with a Z-scheme design, was synthesized for photocatalysis, sonocatalysis, and sono-photocatalysis methyl orange (MO) and indigo carmine (IC) dyes simultaneously. The properties of the Zeolite 4A/WO3/CuO composite were thoroughly investigated using various techniques, and the results confirmed the synthesis of the desired catalyst system. In the sono-photocatalytic process, using the Zeolite 4A/WO3/CuO composite, the maximum efficiency for MO (99.12 %) and IC (97.24 %) was achieved at pH of 2 and 3, with a catalyst dosage of 0.15 g/L, a dye concentration of 10 mg/L, a contact time of 25 min, and H2O2 dosage of 30 µL/100 mL. The dye elimination efficiency using the sono-photocatalytic process was reduced in the presence of Cl- and PO43- in the distilled water. The efficiency also declined in the medium of river and well water resources. Moreover, the Zeolite 4A/WO3/CuO catalyst maintained over 90 % of its performance even after five reuse cycles. Based on the kinetic study, the sono-photocatalytic process exhibited higher activation for the removal of MO (k: 0.1946 min−1 and t1/2: 3.561) and IC (k: 0.1433 min−1 and t1/2: 4.836) than other processes. The synergy values for the MO and IC degradation using the Zeolite 4A/WO3/CuO composite were determined to be 2.167 and 2.303, respectively. The impact of various scavengers demonstrated that in the degradation processes of the target dyes using the sono-photocatalytic process, different active species like OH•, e-, h+, and O2–• are involved. The purification of dye-laden water using the sono-photocatalytic process was not toxic for plant germination, microorganisms, and fish, highlighting the successful biocompatibility of the process for dye removal.

Nanostructured Composite of Starch/Silica Hybrid Decorated with Titanium Oxide Nanoparticles for Photocatalytic, Sonocatalytic, and Sonophotocatalytic

AbstractNanocomposite‐based heterostructure plays an important role in both industrial and advanced applications. A series of TiO2 nanoparticles decorated on silica/starch hybrid material (TiO2(x)@SiO2(x)@Starch nanocomposites) is synthesized using a facile sol–gel method. The intrinsic characteristics of the as‐prepared nanocomposites are studied using a variety of techniques. In this study, the degradation of paracetamol (PCT) is investigated in the presence of TiO2(x)@SiO2(x)@Starch nanocomposites. Photocatalysis and sonocatalysis systems are used separately and simultaneously in presence of sunlight and low‐power ultrasound. The adsorption results are essential factor in the degradation process. The non‐linear transform of the kinetics is further used to determine the characteristic parameters of TiO2(x)@SiO2(x)@Starch nanocomposites. The obtained results confirm that the experimental kinetic data follow the pseudo‐first order model in photocatalytic, sonocatalytic, and sonophotocatalytic processes but the rate constant of sonophotocatalysis is higher than the sum of it at photocatalysis and sonocatalysis process. This work develops a new sono‐photo active hybrid process for potential application in wastewater treatment. Additionally, the prepared TiO2 nanoparticles with silica/starch hybrid material perform antimicrobial activity. The antimicrobial activity is increased parallel with the TiO2 percent. The broad‐spectrum antimicrobial activity of nanocomposites is noticed at the highest percentage of TiO2 in TiO2(0.8)@SiO2(0.2)@Starch.

Simultaneous anionic dyes degradation via H2O2 activation using Zeolite 4A/ZnO/Fe2(MoO4)3 nanoparticles in a sono-photocatalytic process

In this paper, a new sono-photocatalyst of Zeolite 4A/Zinc oxide/ Iron molybdate (Zeolite 4A/ZnO/Fe2(MoO4)3) nanoparticle was fabricated and used to decompose methyl orange (MO) and brilliant blue simultaneously (BB) dyes in the presence of ultrasonic waves and ultraviolet (UVC). The feature of the catalyst and its components was fully characterized. The results showed that the efficiency of the sono-photocatalytic process in the dye oxidation was higher than the photocatalytic and sonocatalytic processes. The synergistic effect of the sono-photocatic and photo-catalytic process for the MO and BB oxidation using Zeolite 4A/ZnO/Fe2(MoO4)3 was obtained 1.796 and 1.944, respectively. The active species of OH and h+ had a prominent role in the dye oxidation. Also, the Zeolite 4A/ZnO/Fe2(MoO4)3 catalyst was stable and reused seven times in the MO and BB decomposition. The ability of Zeolite 4A/ZnO/Fe2(MoO4)3 catalyst to treat actual wastewater samples was successfully explored. The by-products of purified wastewater were not toxic for the growth and germination of Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and Lens esculinaris. The studied photocatalyst removed dyes effectively in a reactor with ultrasonic waves and UVC.

Decorating 2D graphene oxides sheets with spherical shaped Fe3O4 for the applications of supercapacitors and sunlight induced sonophotocatalytic degradation of methylene blue dye

This study introduces a versatile nanocomposite material composed of Fe3O4 and GO/Fe3O4, demonstrating remarkable enhancements in sonication involved sonophotocatalytic and supercapacitor applications. The GO/Fe3O4 nanocomposite (NCs) were synthesized through a facile chemical precipitation method and subjected to comprehensive characterization using diverse techniques, including Field emission scanning electron microscopy (FESEM), Transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy, UV-Visible spectroscopy (UV-Vis), Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The successful synthesis of both Fe3O4 and GO/Fe3O4 NCs was confirmed through XRD analysis, while UV-Vis measurements indicated a reduced bandgap for the nanocomposites. FESEM and TEM examinations unveiled a uniform distribution of Fe3O4 nanoparticles over the GO nanosheets, reinforcing the meticulous design of the nanostructure. Leveraging their unique properties, the synthesized nanocomposites were employed as efficient sonication and sun-light driven photocatalysts for the degradation of methylene blue (MB) dye. Impressively, the GO/Fe3O4 NCs exhibited exceptional sonophotocatalytic process, achieving rapid degradation rates (98.68% in 30 min) for MB dye under direct sunlight exposure. Furthermore, the engineered nanocomposites demonstrated outstanding suitability as electrode materials for supercapacitor applications. The GO/Fe3O4 NCs showcased a peak specific capacitance of 690.03 Fg−1 at a current density of 1 Ag−1 was achieved, with the cyclic stability remaining at 91% after 8000 cycles. The enhanced catalytic and the specific capacitance is due to the synergistic effect create between the Fe3O4 NPs and GO via the effective bonding of Fe-O-C. These findings reveals that the prepared nanohybrid is effective material for the dye degradation and the energy storage applications.

Cu:TiO2 nanoparticles prepared by planetary ball mill with enhanced sonophotocatalytic performance with visible light

AbstractIn this research, pure and Cu(II)‐doped TiO2 nanoparticles (NPs) were synthesized via a simple and nontoxic approach to fabricate a nanocatalyst for the oxidative sonophotocatalytic degradation of phenol. TiO2 NPs were prepared using a solvothermal method and doped with Cu(II) by high‐energy planetary ball mill. The as‐synthesized NPs were identified and characterized by X‐ray diffraction, energy‐dispersive X‐ray, and transmission electron microscopy techniques. The doped NPs were used for the first time in pollutant decomposition using phenol as a model pollutant in low‐energy and low‐frequency ultrasound at room temperature and pH = 7 in the presence of visible light. The progress of the pollutant degradation was followed by UV–Vis spectrophotometry. After about 60 min of sonophotocatalytic process (dual irradiation [visible light + ultrasound] in the presence of doped NPs), around 75% of the phenol degraded, with a rate constant of about 0.024 min−1. The sonophotocatalytic process was compared with photocatalysis and sonocatalysis processes conducted in the same conditions. Importantly, the combination of visible light and ultrasound irradiation in a sonophotocatalytic decomposition reaction represented about 58% of the synergy effect, demonstrating a positive synergy between the photocatalytic and sonocatalytic processes. The optimum condition was used to degrade the commercial sample (amoxicillin) with excellent performance. The reusability test represented the excellent stability of doped catalysts within four consecutive runs with less fading in their sonophotocatalytic reaction. This feature proves the reusability potential of the doped catalyst to be used in the commercial and industrial directions. The performance of the doped catalyst was affected severely by the addition of different scavengers, and based on the results, the sonophotocatalytic mechanism was discussed.

Sonophotocatalytic water splitting by BaTiO3@SrTiO3 core shell nanowires

Sonophotocatalysis has garnered significant attention due to its potential to enhance advanced oxidation processes, particularly water splitting, by employing materials with combined sonocatalytic and photocatalytic properties. In this study, we synthesized and investigated core–shell BaTiO3@SrTiO3 nanowires (BST NWs) with varying Sr/Ba molar ratios (2.5:7.5, 5.0:5.0, 7.5:2.5 mM, denoted as BST-1, BST-2, and BST-3, respectively) as catalysts for hydrogen production through water splitting. The piezoelectric nanowires demonstrated hydrogen evolution via both sonocatalysis and photocatalysis. In the sonophotocatalysis process, the ultrasonic vibration induced mechanical forces on the BST nanowires, thereby establishing a built-in electric field. This built-in electric field facilitated the effective separation of photo-generated charge carriers and prolonged their lifetimes, leading to a synergistic enhancement of hydrogen evolution. The pristine BaTiO3 and SrTiO3 nanowires exhibited relatively low hydrogen evolution rates (HER) of 7.0 and 6.0 µmol·g−1min−1, respectively. In contrast, the core–shell nanowires exhibited a substantial improvement in the hydrogen evolution rate. The HER increased with the addition of Sr, and BST-1, BST-2, and BST-3 achieved HERs of 12.0, 13.5, and 18.0 µmol·g−1min−1, respectively. The superior performance of BST-3 nanowires can be attributed to their highest piezoelectric potential and largest surface area. Additionally, BST-3 nanowires demonstrated remarkable stability over multiple cycles, validating their practical applicability as efficient photocatalysts.

WS2-intercalated Ti3C2Tx MXene/TiO2-stacked hybrid structure as an excellent sonophotocatalyst for tetracycline degradation and nitrogen fixation

Designing a heterostructure nanoscale catalytic site to facilitate N2 adsorption and photogenerated electron transfer would maximize the potential for photocatalytic activity and N2 reduction reactions. Herein, we have explored the interfacial TiO2 nanograins between the Ti3C2TxMXene-WS2 heterostructure and addressed the beneficial active sites to expand the effective charge transfer rate and promote sonophotocatalytic N2 fixation. Benefiting from the interfacial contact and dual heterostructure interface maximizes the photogenerated carrier separation between WS2 and MXene/TiO2. The sonophotocatalytic activity of the MXene@TiO2/WS2 hybrid, which was assessed by examining the photoreduction of N2 with ultrasonic irradiation, was much higher than that of either sonocatalytic and photocatalytic activity because of the synergistic sonocatalytic effect under photoirradiation. The Schottky junction between the MXene and TiO2 on the hybrid MXene/TiO2-WS2 heterostructure resulted in the sonophotocatalytic performance through effective charge transfer, which is 1.47 and 1.24 times greater than MXene-WS2 for nitrogen fixation and pollutant degradation, respectively. Under the sonophotocatalytic process, the MXene/TiO2-WS2 heterostructure exhibits a decomposition efficiency of 98.9 % over tetracycline in 90 min, which is 5.46, 1.73, and 1.10 times greater than those of sonolysis, sonocatalysis, and photocatalysis, respectively. The production rate of NH3 on MXene/TiO2-WS2 reached 526 μmol g−1h−1, which is 3.17, 3.61, and 1.47 times higher than that of MXene, WS2, and MXene-WS2, respectively. The hybridized structure of MXene-WS2 with interfacial surface oxidized TiO2 nanograins minimizes the band potential and improves photocarrier use efficiency, contributing directly to the remarkable catalytic performance towards N2 photo fixation under visible irradiation under ultrasonic irradiation. This report provides the strategic outcome for the mass carrier transfer rate and reveals a high conversion efficiency in the hybridized heterostructure.

Enhanced sonophotocatalytic degradation of amoxicillin antibiotics using Fe3O4@SiO2/PAEDTC surrounded by MIL-101(Fe) in aquatic environment under the COVID-19 pandemic

In the conditions of corona disease, the need for antibiotics in the world has quadrupled, so it is required to remove their residues from the environment. A core–shell metal–organic framework (MOF) composed of Fe3O4, SiO2, and MIL-101 was synthesized by hydrothermal method and used as a sonophotocatalyst for the amoxicillin (AMX) degradation from aqueous solution. The features of the new MOF were determined by SEM, TEM, XRD, FTIR, and BET techniques. The specific area of core–shell magnetic particles was 992 m2/g, which was indicative of its usability to adsorb pollutants and photons. Complete degradation of AMX was achieved by sonophotocatalysis process based on prepared nanocomposite at pH of 5, UV intensity of 36 W, AMX concentration of 50 mg/L, US frequency of 36 kHz, and time of 25 min. Kinetic study with pseudo-first order reaction for the decomposition of AMX showed the order of kinetic constant rate as Ksonophotocatalytic > Kphotocatalytic > Ksonocatalytic > Kadsorption. Hydroxyl radicals (•OH) and holes (h+) were respectively determined as the main species in the decomposition of AMX by performing quenching experiments. Less than an 8% reduction in AMX degradation rate was observed by the sonophotocatalytic process in the presence of prepared nanocomposite during six consecutive reaction cycles. Removal rates of TOC > 77% and BOD5/COD ratio > 0.4 showed that AMX was converted to CO2, H2O, and simple degradable compounds during the sonophotocatalysis process. A toxicity study with the microbial culture of Escherichia coli (E. coli) demonstrated a lower inhibition rate in the sonophotocatalytic process compared to photolysis and photocatalytic processes. All the laboratory results proved that the Fe3O4@SiO2@MIL-101(Fe) is an encouraging candidate for AMX degradation to preserve the ecosystem.

Mesoporous cobalt oxide nanoparticles synthesized by a sonochemical method in the presence of a deep eutectic solvent for oxidative sonophotocatalytic decomposition of caffeine

Herein, for the first time, we have prepared mesoporous Co3O4 nanoparticles (NPs) by the ultrasound-assisted method in the presence of deep eutectic solvent (DES) for sonophotocatalytic degradation of caffeine (CAF). The porosity, crystallinity, and morphology of the as-synthesized NPs were investigated by using Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), and transmission electron microscopy (TEM) techniques. The as-prepared NPs were applied in sonophotocatalytic, photocatalytic, and sonocatalytic degradation of CAF in low energy and low-frequency ultrasound at neutral pH. The sonophotocatalytic process was the most effective in degrading CAF, reaching about 99.5 % in less than an hour with a pseudo-first-order rate constant of 0.0902 min−1. The photocatalytic and sonocatalytic processes degraded 83.4 % and 22.7 % of CAF, respectively, with lower rate constants of 0.0288 and 0.0049 min−1. Notably, the simultaneous application of UV light and ultrasound irradiation in a sonophotocatalytic decomposition process had a positive synergy effect of about 62.64 %. The commercial tablet was degraded by the optimum sonophotocatalytic process to prove the applicability of the catalyst. The reusability test of the NPs was examined, and after four consecutive uses, the NPs had negligible fading of their sonophotocatalytic performance. Due to the excellent sonophotocatalytic performance of the NPs, it is a suitable candidate for a broad range of environmental and remediation applications.

Ultrasonic-assisted photocatalytic degradation of various organic contaminants using ZnO supported on a natural polymer of sporopollenin

Water resource pollution by organic contaminants is an environmental issue of increasing concern. Here, sporopollenin/zinc oxide (SP/ZnO) was used as an environmentally friendly and durable catalyst for sonophotocatalytic treatment of three organic compounds: direct blue 25 (DB 25), levofloxacin (LEV), and dimethylphtalate (DMPh). The resulting catalyst had a 2.65 eV bandgap value and 9.81 m2/g surface area. The crystalline structure and functional groups of SP/ZnO were confirmed by X-ray diffraction (XRD) and Fourier transforms infrared spectroscopy (FTIR) analyses. After 120 min of the sonophotocatalysis, the degradation efficiencies of DB 25, LEV, and DMPh by SP/ZnO were 86.41, 75.88, and 62.54%, respectively, which were higher than that of the other investigated processes. The role of reactive oxygen species were investigated using various scavengers, enhancers, photoluminescence, and o-phenylenediamine. Owing to its stability, the catalyst exhibited good reusability after four consecutive cycles. In addition, the high integrity of the catalyst was confirmed by scanning electron microscopy (SEM), XRD, and FTIR analyses. After four consecutive examinations, the leaching of zinc in the aqueous phase was < 3 mg/L. Moreover, gas chromatography-mass spectrometry (GC–MS) analyses indicated that the contaminants were initially converted into cyclic compounds and then into aliphatic compounds, including carboxylic acids and animated products. Thus, this study synthesized an environmentally friendly and reusable SP/ZnO composite for the degradation of various organic pollutants using a sonophotocatalytic process.

Mechanistic insight into humic acid-enhanced sonophotocatalytic removal of 17β-estradiol: Formation and contribution of reactive intermediates

In this study, humic acid (HA) enhanced 17β-estradiol (17β-E2) degradation by Er3+-CdS/MoS2 (ECMS) was investigated under ultrasonic and light conditions. The degradation reaction rate of 17β-E2 was increased from (14.414 ± 0.315) × 10−3 min−1 to (122.677 ± 1.729) × 10−3 min−1 within 90 min sonophotocatalytic (SPC) reaction with the addition of HA. The results of quenching coupled with chemical probe experiments indicated that more reactive intermediates (RIs) including reactive oxygen species (ROSs) and triplet-excited states were generated in the HA-enhanced sonophotocatalytic system. The triplet-excited states of humic acid (3HA*), hydroxyl radical (•OH), and superoxide radical (•O2−) were the dominant RIs for 17β-E2 elimination. In addition, the energy- and electron-transfer process via coexisting HA also account for 12.86% and 29.24% contributions, respectively. The quantum yields of RIs in the SPC-ECMS-HA system followed the order of 3HA* > H2O2 >1O2 > •O2−> •OH. Moreover, the spectral and fluorescence characteristics of HA were further analyzed during the sonophotocatalytic reaction process. The study expanded new insights into the comprehension of the effects of omnipresent coexisting HA and RIs formation for the removal of 17β-E2 during the sonophotocatalytic process.