Enhanced activation of persulfate by CuCoFe2O4@MC/AC as a novel nanomagnetic heterogeneous catalyst with ultrasonic for metronidazole degradation

Green and environmentally friendly architecture of starch-based ternary magnetic biocomposite (Starch/MIL100/CoFe2O4): Synthesis and photocatalytic degradation of tetracycline and dye

The presence of tetracycline and dye as organic contaminants has led to the poisoning of wastewater. The aim of this study is to synthesize a novel biocomposite material by decorating natural starch polymer granules with metal-organic framework (MIL100) and cobalt ferrite magnetic (CoFe2O4) nanoparticles. The synthesized ternary magnetic biocomposite (Starch/MIL100/CoFe2O4) was used for the photocatalytic degradation of methylene blue (MB) and tetracycline (TCN) using LED visible light. The synthesis of the biocomposite was confirmed through comprehensive analyses (XRD, SEM, FTIR, BET, EDX, MAP, DRS, pHzpc, TGA, and Raman). The evaluation examined the influence of initial pollutant concentration, catalyst dosage, pH, and the impact of anions on pollutant removal. The results show that the pollutant degradation ability of biocomposite has been significantly improved, so that the base biopolymer, starch, achieved 18% tetracycline degradation, but when decorated with MIL100 and cobalt ferrite, it increased to 91.2%. It was observed that the degradation for methylene blue improved from 12% for starch to 96.6% for the magnetic biocomposite. The tetracycline degradation decreased by more than 20% in the presence of NaCl, NaNO3, and Na2SO4. The finding shows that the biocomposite adheres to first-order kinetics for both pollutants. The scavengers test identified hydroxyl radicals as the most effective active species in the degradation process. High stability, even after passing 5 cycles of recycling was observed for the biocomposite. The results indicated that the facile and green synthesized Starch/MIL100/CoFe2O4 magnetic biocomposite could be used as an effective photocatalyst for the degradation of Tetracycline and dye at room temperature.

Fully Floatable Mortise-and-Tenon Architecture for Synergistically Photo/Sono-Driven Evaporation Desalination and Plastic-Enabled Value-Added Co-Conversion of H2O and CO2

Establishing an advanced ecosystem incorporating freshwater harvesting, plastic utilization, and clean fuel acquisition is profoundly significant. However, low-efficiency evaporation, single energy utilization, and catalyst leakage severely hinder sustainable development. Herein, a nanofiber-based mortise-and-tenon structural Janus aerogel (MTSJA) is strategically designed in the first attempt and supports Z-scheme catalysts. By harnessing of the upper hydrophilic layer with hydrophilic channels embedding into the hydrophobic bottom layer to achieve tailoring bottom wettability states. MTSJA is capable of a fully-floating function for lower heat loss, water supply, and high-efficiency solar-to-vapor conversion. Benefiting from the ultrasonic cavitation effect and high sensitivity of materials to mechanical forces, this is also the first demonstration of synergistic solar and ultrasound fields to power simultaneous evaporation desalination and waste plastics as reusable substrates generating fuel energy. The system enables persistent desalination with an exceptional evaporation rate of 3.1 kg m-2 h-1 and 82.3% efficiency (21 wt.% NaCl solution and 1 sun), and realizes H2, CO, and CH4 yields with 16.1, 9.5, and 3 µmol h-1 g-1, respectively. This strategy holds great potential for desalination and plastics value-added transformation toward clean energy and carbon neutrality.

Effect of Fenton process as a pretreatment in the phytoremediation of metronidazole by Scirpus lacustris

The present study evaluated the effect of the Fenton process as pretreatment for metronidazole (MNZ) removal coupled with a phytoremediation system using Scirpus lacustris as macrophyte. Initial concentrations of 0.5, 5, 10, 15, and 20 mg MNZ/L were studied in batch cultures. Results obtained in the MNZ removal by phytoremediation showed efficiencies of 93 ± 2%, 81 ± 4%, 85 ± 1%, 84 ± 2%, and 87 ± 6%, respectively. The metronidazole pretreated by the Fenton process and subsequently fed to the phytoremediation system increased the removal efficiencies up to 93 ± 3%, 99 ± 1%, 99 ± 4%, 94 ± 2%, and 94 ± 3%, respectively. Individual studies with Scirpus lacustris in touch with metronidazole displayed relative growth rates of 0.02-0.04 d-1, showing the not toxic effect of the antibiotic on the macrophyte growth. On the other hand, the BMG kinetic model best describes the removal of MNZ by phytoremediation. Finally, applying the Fenton process as a pretreatment makes the MNZ more assimilable for the phytoremediation system, converting the integration of Fenton with the phytoremediation like other attractive technology to be considered in removing emerging compounds.

From wastewater to clean water: Recent advances on the removal of metronidazole, ciprofloxacin, and sulfamethoxazole antibiotics from water through adsorption and advanced oxidation processes (AOPs)

Antibiotics released into water sources pose significant risks to both human health and the environment. This comprehensive review meticulously examines the ecotoxicological impacts of three prevalent antibiotics-ciprofloxacin, metronidazole, and sulfamethoxazole-on the ecosystems. Within this framework, our primary focus revolves around the key remediation technologies: adsorption and advanced oxidation processes (AOPs). In this context, an array of adsorbents is explored, spanning diverse classes such as biomass-derived biosorbents, graphene-based adsorbents, MXene-based adsorbents, silica gels, carbon nanotubes, carbon-based adsorbents, metal-organic frameworks (MOFs), carbon nanofibers, biochar, metal oxides, and nanocomposites. On the flip side, the review meticulously examines the main AOPs widely employed in water treatment. This includes a thorough analysis of ozonation (O3), the photo-Fenton process, UV/hydrogen peroxide (UV/H2O2), TiO2 photocatalysis, ozone/UV (O3/UV), radiation-induced AOPs, and sonolysis. Furthermore, the review provides in-depth insights into equilibrium isotherm and kinetic models as well as prospects and challenges inherent in these cutting-edge processes. By doing so, this review aims to empower readers with a profound understanding, enabling them to determine research gaps and pioneer innovative treatment methodologies for water contaminated with antibiotics.

Degradation and mechanism of PAHs by Fe-based activated persulfate: Effect of temperature and noble metal

The accumulation of contaminants like PAHs in soil due to industrialization, urbanization, and intensified agriculture poses environmental challenges, owing to their persistence, hydrophobic nature, and toxicity. Thus, the degradation of PAHs has attracted worldwide attention in soil remediation. This study explored the effect of noble metal and temperature on the degradation of various polycyclic aromatic hydrocarbons (PAHs) in soil, as well as the types of reactive radicals generated and mechanism. The Fe-Pd/AC and Fe-Pt/AC activated persulfate exhibited high removal efficiency of 19 kinds of PAHs, about 79.95 % and 83.36 %, respectively. Fe-Pt/AC-activated persulfate exhibits superior degradation efficiency than that on Fe-Pd/AC-activated persulfate, due to the higher specific surface area and dispersity of Pt particles, thereby resulting in increased reactive radicals (·OH, SO4-· and ·OOH). Additionally, thermal activation enhances the degradation of PAHs, with initial efficiencies of 64.20 % and 55.49 % on Fe-Pd/AC- and Fe-Pt/AC-activated persulfate systems respectively, increasing to 76.05 % and 73.14 % with elevated temperatures from 21.5 to 50 °C. Metal and thermal activation facilitate S2O82- activation, generating reactive radicals, crucial for the degradation of PAHs via ring opening and oxygen hydrogenation reactions, yielding low-ring oxygen-containing derivatives such as organic acids, keto compounds, ethers, and esters. Furthermore, understanding the impact of parameters such as activation temperature and the types of noble metals on the degradation of PAHs within the activated persulfate system provides a theoretical foundation for the remediation of PAH-contaminated soil.

Photocatalytic degradation of Acid Red 18 by synthesized AgCoFe2O4@Ch/AC: Recyclable, environmentally friendly, chemically stable, and cost-effective magnetic nano hybrid catalyst

Chitosan (Ch) is a linear biodegradable natural carbohydrate polymer and the most appealing biopolymer, such as low-cost biodegradability, biocompatibility, hydrophilicity, and non-toxicity. In this case, Ch was utilized to synthesize AgCoFe2O4@Ch/Activated Carbon (AC) by the modified microwave-assisted co-precipitation method. The physical and chemical structure of magnetic nanocomposites was analyzed and characterized by Field Emission Scanning Electron Microscope (FESEM), Transmission electron microscopy (TEM), X-ray diffraction (XRD), Energy Dispersive Spectroscopy (EDS), Diffuse Reflection Spectroscopy (DRS), Value stream mapping (VSM), Fourier transform spectroscopy (FTIR) and BET. The effects of various parameters on the removal of dye (Acid Red18), including catalyst dose, dye concentration, pH, and time were studied. Results showed that the highest removal efficiencies were 96.68 % and 84 % for the synthetic sample and actual wastewater, respectively, in optimal conditions (pH: 3, the initial dye concentration: 10 mgL-1, the catalyst dose: 0.14 gL-1, time: 50 min). Mineralization, according to the COD analysis, was 89.56 %. Photocatalytic degradation kinetics of Acid Red 18 followed pseudo-first order and Langmuir-Hinshelwood with constants of kc = 0.12 mg L-1 min-1 and KL-H = 0.115 Lmg-1. Synthesized photocatalytic AgCoFe2O4@Ch/AC showed high stability and after five recycling cycles was able to remove the pollutant with an efficiency of 85.6 %. So, the synthesized heterogenous magnetic nanocatalyst AgCoFe2O4@Ch/AC was easily recycled from aqueous solutions and it can be used in the removal of dyes from industries with high efficiency.

Activation of peroxymonosulfate with ZIF-67-derived Co/N-doped porous carbon nanocubes for the degradation of Congo red dye

In this study, porous carbon nanocubes encapsulated magnetic metallic Co nanoparticles (denoted as Co@N-PCNC) was prepared via pyrolyzing ZIF-67 nanocubes precursor at 600 °C and characterized by various technologies. It was used to activate peroxymonosulfate (PMS) to degrade Congo red (CR) dye efficiently. Over 98.45% of 50 mg L-1 CR was degraded using 0.033 mM PMS activated by 75 mg L-1 Co@N-PCNC within 12 min. The free radical quenching experiments were performed to reveal the nature of the reactive oxygen species radicals generated throughout the catalytic oxidation of CR. The effects of common inorganic anions and the water matrix on CR removal were studied. Moreover, the results of the kinetic study revealed the suitability of the pseudo-first-order and Langmuir-Hinshelwood kinetic models for illustrating CR degradation using the Co@N-PCNC/PMS system. Ultimately, the Co@N-PCNC displayed good operational stability, and after five cycles, the CR removal rate can still maintain over 90% after 12 min.

Bisphenol A adsorption using modified aloe vera leaf-wastes derived bio-sorbents from aqueous solution: kinetic, isotherm, and thermodynamic studies

Reactive-oxygen-species are produced more often in the body when bisphenol A (BPA), an endocrine-disrupting-substance, is present. In this investigation, bio-sorbents from an aqueous solution adapted from Aloe-vera were used to survey BPA removal. Aloe-vera leaf wastes were used to create activated carbon, which was then analyzed using Fourier transform infrared (FTIR), Field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Thermogravimetric analysis (TGA), Zeta potential, and Brunauer-Emmett-Teller (BET) techniques. It was revealed that the adsorption process adheres to the Freundlich isotherm model with R2>0.96 and the pseudo-second-order kinetic model with R2>0.99 under ideal conditions (pH = 3, contact time = 45 min, concentration of BPA = 20 mg.L-1, and concentration of the adsorbent = 2 g.L-1). After five-cycle, the efficacy of removal was greater than 70%. The removal of phenolic-chemicals from industrial-effluent can be accomplished with the assistance of this adsorbent in a cost-effective and effective-approach.

Composite of a thiacalix[4]arene-copper(I) metal-organic framework and mesoporous carbon for efficient electrochemical detection of antibiotics

Abundant use of nitrofurantoin (NFT) and metronidazole (MTZ) antibiotics has led to excessive residues in the environments and humans, resulting in serious damage to the human body and ecosystem. Therefore, effective detection of NFT and MTZ is exceedingly necessary. In this regard, metal-organic frameworks (MOFs) are promising materials as electrochemical sensors. Herein, we synthesized a new two-dimensional thiacalix [4]arene-copper (I) MOF (Cu-TC4A-M). This MOF was mixed with mesoporous carbon (MC) to a give Cu-TC4A-M@MC composite. In addition, the sensors of Cu-TC4A-M@MC(2:1)/GCE and Cu-TC4A-M@MC(1:2)/GCE were achieved (GCE = glassy carbon electrode), and then were applied for effectively detecting NFT and MTZ, respectively. Markedly, the two sensors exhibited satisfactory linear detection range, anti-interference, reproducibility and stability. When they were utilized in the real samples, such as human serum, urine, tap water and lake water, satisfactory recoveries were attained. The relative standard deviations (RSDs) were in the range of 1.16 % ∼ 1.92 % for NFT and 0.95 % ∼ 2.33 % for MTZ. This work provided a new application prospect for the thiacalix [4]arene-based MOFs as promising candidate materials for NFT and MTZ detection.

Preparation of Mn-doped sludge biochar and its catalytic activity to persulfate for phenol removal

In recent years, the increasing prevalence of phenolic pollutants emitted into the environment has posed severe hazards to ecosystems and living organisms. Consequently, there is an urgent need for a green and efficient method to address environmental pollution. This study utilized waste sludge as a precursor and employed a hydrothermal-calcination co-pyrolysis method to prepare manganese (Mn)-doped biochar composite material (Mn@SBC-HP). The material was used to activate peroxydisulfate (PDS) for the removal of phenol. The study investigated various factors (such as the type and amount of doping metal, pyrolysis temperature, catalyst dosage, PDS dosage, pH value, initial phenol concentration, inorganic anions, and salinity) affecting phenol removal and the mechanisms within the Mn@SBC-HP/PDS system. Results indicated that under optimal conditions, the Mn@SBC-HP/PDS system achieved 100% removal of 100 mg/L phenol within 180 min, with a TOC removal efficiency of 82.7%. Additionally, the phenol removal efficiency of the Mn@SBC-HP/PDS system remained above 90% over a wide pH range (3-9). Free radical quenching experiments and electron spin resonance (ESR) results suggested that hydroxyl radicals (·OH) and sulfate radicals (SO4-) yed a role in the removal of phenol through radical pathways, with singlet oxygen (1O2) being the dominant non-radical pathway. The phenol removal efficiency remained above 90%, demonstrating the excellent adaptability of the Mn@SBC-HP/PDS system under the interference of coexisting inorganic anions or increased salinity. This study proposes an innovative method for the resource utilization of waste, creating metal-biochar composite catalysts for the remediation of water environments. It provides a new approach for the efficiency of organic pollutants in water environments.

Investigating the improvement of the quality of industrial effluents for reuse with added processes: coagulation, flocculation, multi-layer filter and UV

Reuse of wastewater is one of the ways to develop water resources. In addition to the need for drinking water, many industries also need high-quality water in the production line. Therefore, the purpose of the present study is to investigate the advanced treatment of the wastewater treatment plant of Morche Khort industrial town using the processes of coagulation, flocculation with aeration, multi-layer filter, and disinfection by ultraviolet radiation to increase the quality of wastewater and reuse it in industries. In this study, to investigate the effect of coagulation and flocculation units along with aeration, filtration, and disinfection by ultraviolet rays (UV), on the quality of the secondary effluent from the wastewater treatment plant of Morche Khort industrial town, they were operated on a pilot scale. Polyaluminum chloride (PAC) was used as a coagulant. Layering of three layers of sand filter, from bottom to top including granulated silica at a height of 10 cm, sand at a height of 20 cm, and activated carbon at a height of 70 cm was used. The input and output sampling points of each unit were considered. By repeating twice in five stages of flow rates of 1, 2, 4, 6, and 8 (L/min), the samples were collected to determine COD, TSS, TDS, turbidity, pH, hardness, total coliform, and fecal coliform. Jar test results showed that Alum coagulant works almost the same as PAC in removing turbidity, but the efficiency of removing organic substances by PAC coagulant is higher than that of Alum at lower doses. The results of this study showed that the efficiency of the coagulation and flocculation process in removing turbidity, COD, TSS, TDS, and fat was 56.88%, 46.66%, 38%, 23.19%, and 91.43% respectively. In the current study, the results of the wastewater entering the sand filter showed that the percentage of removal efficiency with a loading rate of 1 (L/min) was turbidity, TSS, COD, TDS, and fat was 16. 93%, 56.84%, 50%, 5.67%, 33.44% respectively. In the UV disinfection unit, the removal efficiency percentage with a loading rate of 1 (L/min) for COD, TSS, turbidity, hardness, total coliform, and fecal coliform is 16%, 3.45%, 3.58%, 5.21%, 99.88%, and 98.37% respectively. Coagulation and flocculation system-multi-layer filter and disinfection can remove chemical-physical and microbial parameters to an acceptable level for using water in advanced purification systems and also for irrigation.

Facile and green synthesis of recyclable, environmentally friendly, chemically stable, and cost-effective magnetic nanohybrid adsorbent for tetracycline adsorption

Antibiotic contamination of water sources, particularly tetracycline (TC) contamination, has emerged as one of the global issues that needs action. In this research, ZnCoFe2O4@Chitosan (Ch) as a magnetic nanohybrid adsorbent was synthesized using the microwave-assisted co-precipitation method, and their efficiency for the TC adsorption process was investigated. FESEM (Field Emission Scanning Electron Microscope), EDX (Energy Dispersive X-ray), Mapping and line Scan, XRD (X-Ray Diffraction), FTIR (Fourier Transform Infrared Spectrometer), VSM (Vibrating Sample Magnetometer), Thermogravimetric analysis (TGA) and BET (Brunauer Emmett Teller) techniques were used to check and verify its physical and chemical properties. The removal of TC via the adsorption process from synthetic and real wastewater samples was investigated. The factors determining the TC adsorption process, comprising tetracycline concentration (5-30 mg/L), adsorbent dosage (0.7-2 g/L), contact time (2-45 min), and pH (3-11), were evaluated. The removal effectiveness for the synthetic sample and the real wastewater sample was 93 % and 80 %, respectively, under the ideal TC adsorption process parameters of pH 3, adsorbent dosage 1 g/L, TC initial concentration 5 mg/L, and contact time 30 min. According to kinetic and equilibrium studies, the adsorption of TC by ZnCoFe2O4@Ch follows pseudo-second-order kinetics and the Freundlich isotherm. Additionally, it was determined through the analysis of thermodynamic data that the process of exothermic adsorption is spontaneous and is followed by a decrease in disorder (ΔH = -15.16 kJ/mol, ΔS = -28.69 kJ/mol, and ΔG = -6.62 kJ/mol). After five cycles of recovery and regeneration, the ZnCoFe2O4@Ch magnetic nanocomposite was able to remove 65 % of the TC pollutant and had good chemical stability. The results showed that the magnetic nano-adsorbent ZnCoFe2O4@Ch is a novel magnetic nano-adsorbent with high adsorption capacity that can be utilized to eliminate pharmaceutical contaminants from aqueous solutions.

Application of biochar in microbial fuel cells: Characteristic performances, electron-transfer mechanism, and environmental and economic assessments

Biochar is a by-product of thermochemical conversion of biomass or other carbonaceous materials. Recently, it has garnered extensive attention for its high application potential in microbial fuel cell (MFC) systems owing to its high conductivity and low cost. However, the effects of biochar on MFC system performance have not been comprehensively reviewed, thereby necessitating the evaluation of the efficacy of biochar application in MFCs. In this review, biochar characteristics were outlined based on recent publications. Subsequently, various applications of biochar in the MFC systems and their probable processes were summarized. Finally, proposals for future applications of biochar in MFCs were explored along with its perspectives and an environmental evaluation in the context of a circular economy. The purpose of this review is to gain comprehensive insights into the application of biochar in the MFC systems, offering important viewpoints on the effective and steady utilization of biochar in MFCs for practical application.

A walnut shell biochar-nano zero-valent iron composite membrane for the degradation of carbamazepine via persulfate activation

In this study, novel walnut shell biochar-nano zero-valent iron nanocomposites (WSBC-nZVI) were synthesized using a combined pyrolysis/reduction process. WSBC-nZVI displayed a high removal efficiency (86 %) for carbamazepine (CBZ) compared with walnut shell biochar (70 %) and nano zero-valent iron (76 %) in the presence of persulfate (PS) (0.5 g/L catalyst, 10 mg/L CBZ, 1 mM persulfate). Subsequently, WSBC-nZVI was applied for the fabrication of the membrane using a phase inversion method. The membrane demonstrated an excellent removal efficiency of 91 % for CBZ in a dead-end system (2 mg/L CBZ, 1 mM persulfate). In addition, the effect of various operating conditions on the degradation efficiency in the membrane/persulfate system was investigated. The optimum pH was close to neutral, and an increase in CBZ concentration from 1 mg/L to 10 mg/L led to a drop in removal efficiency from 100 % to 24 %. The degradation mechanisms indicated that oxidative species, including 1O2, OH, SO4-, and O2-, all contribute to the degradation of CBZ, while the role of 1O2 is highlighted. The CBZ degradation products were also investigated, and the possible pathways and the predicted toxicity of intermediates were proposed. Furthermore, the practical use of the membrane was validated by the treatment of real wastewater.

Heterogeneous Sono-Fenton like catalytic degradation of metronidazole by Fe3O4@HZSM-5 magnetite nanocomposite

In this research, Fe₃O₄@HZSM-5 magnetic nanocomposite was synthesized via a coprecipitation method for metronidazole (MNZ) degradation from aqueous solutions under ultrasonic irradiation which showed superb sonocatalytic activity. The synthesized magnetite nanocomposite was characterized by using field-emission scanning electron microscope-energy dispersive X-ray Spectroscopy, (FESEM-EDS), Line Scan, Dot Mapping, X-ray diffraction (XRD), vibrating sample magnetometer (VSM), and Brunauer-Emmett-Teller (BET). To investigate the sonocatalytic activity of the Fe₃O₄@HZSM-5 magnetite nanocomposite, the sonocatalytic removal conditions were optimized by evaluating the influences of operating parameters like the dosage of catalyst, reaction time, pH, the concentration of H₂O₂, MNZ concentration, and pH on the MNZ removal. The MNZ maximum removal efficiency and TOC at reaction time 40 min, catalyst dose 0.4 g/L, H₂O₂ concentration 1 mM, MNZ initial concentration 25 mg/L, and pH 7 were achieved at 98% and 81%, respectively. Additionally, the MNZ removal efficiency in the real wastewater sample under optimal conditions was obtained at 83%. The achieved results showed that using Langmuir-Hinshelwood kinetic model K_L-H = 0.40 L mg^-1, K_C = 1.38 mg/L min) can describe the kinetic removal of the process. The radical scavenger tests indicated that the major reactive oxygen species were formed by hydroxyl radicals in the Sono-Fenton-like process. Evaluation of the nanocomposite reusability showed an 85% reduction in the MNZ removal efficiency after seven cycles. Based on the results, it can be concluded that Fe₃O₄@HZSM-5 were synthesized as magnetic heterogeneous nano-catalysts to effectively degrade MNZ, and the observed stability and recyclability demonstrated that Fe₃O₄@HZSM-5 was promising for the treatment of wastewater contaminated with antibiotics.

Degradation of organic pollutants from water by biochar-assisted advanced oxidation processes: Mechanisms and applications

Biochar has shown large potential in environmental remediation because of its low cost, large specific surface area, porosity, and high conductivity. Biochar-assisted advanced oxidation processes (BC-AOPs) have recently attracted increasing attention to the remediation of organic pollutants from water. However, the effects of biochar properties on catalytic performance need to be further explored. There are still controversial and knowledge gaps in the reaction mechanisms of BC-AOPs, and regeneration methods of biochar catalysts are lacking. Therefore, it is necessary to systematically review the latest research progress of BC-AOPs in the treatment of organic pollutants in water. In this review, first of all, the effects of biochar properties on catalytic activity are summarized. The biochar properties can be optimized by changing the feedstocks, preparation conditions, and modification methods. Secondly, the catalytic active sites and degradation mechanisms are explored in different BC-AOPs. Different influencing factors on the degradation process are analyzed. Then, the applications of BC-AOPs in environmental remediation and regeneration methods of different biochar catalysts are summarized. Finally, the development prospects and challenges of biochar catalysts in environmental remediation are put forward, and some suggestions for future development are proposed.

Spinel ferrites materials for sulfate radical-based advanced oxidation process: A review

In the past decade, the sulfate radical-based advanced oxidation processes (SR-AOPs) have been increasingly investigated because of their excellent performance and ubiquity in the degradation of emerging contaminants. Generally, sulfate radicals can be generated by activating peroxodisulfate (PDS) or peroxymonosulfate (PMS). To date, spinel ferrites (SF) materials have been greatly favored by researchers in activating PMS/PDS for their capability and unique superiorities. This article reviewed the recent advances in various pure SF, modified SF, and SF composites for PDS/PMS activation. In addition, synthesis methods, mechanisms, and potential applications of SF-based SR-AOPs were also examined and discussed in detail. Finally, we present future research directions and challenges for the application of SF materials in SR-AOPs.

A facile route to synthesize n-SnO2/p-CuFe2O4 to rapidly degrade toxic methylene blue dye under natural sunlight

In the present study, the n-SnO₂/p-CuFe₂O₄ (p-CFO) complex was prepared by a two-step process. p-CFO synthesized by the molten salt method was coated with SnO₂ synthesized by a facile in situ chemical precipitation method. The formation of n-SnO₂/p-CFO was confirmed by powder X-ray diffraction (PXRD). Scanning electron microscopy (SEM) images showed that the sharp edges of uncoated pyramid-like p-CFO particles were covered by a thick layer of n-SnO₂ on coated p-CFO particles. The complete absence of Cu and only 3 wt% Fe on the surface of the n–p complex observed in the elemental analysis using energy-dispersive X-ray spectroscopy (EDX) on the n–p complex confirmed the presence of a thick layer of SnO₂ on the p-CFO surface. Diffuse reflectance spectroscopy (DRS) was employed to elucidate the bandgap engineering. The n-SnO₂/p-CFO complex and p-CFO showed 87% and 58.7% methylene blue (MB) degradation in 120 min under sunlight, respectively. The efficiency of the n–p complex recovered after 5 cycles (73.5%) and was found to be higher than that of the uncoated p-CFO (58.7%). The magnetically separable property of the n–p complex was evaluated by using vibration sample magnetometry (VSM) measurements and it was confirmed that the prepared photocatalyst can be easily recovered using an external magnet. The study reveals that the prepared complex could be a potential candidate for efficient photodegradation of organic dyes under sunlight due to its efficient recovery and reusability owing to its magnetic properties.

The synthesis of n-SnO₂/p-CuFe₂O₄ to degrade toxic methylene blue dye under natural sunlight and its mechanism.

Infrared spectroscopic monitoring of solid-state processes

We put a spotlight on IR spectroscopic investigations in materials science by providing a critical insight into the state of the art, covering both fundamental aspects, examples of its utilisation, and current challenges and perspectives focusing on the solid state.