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The use of ultrasound in the presence of semiconductor materials is considered a novel technique for the degradation of hazardous organic pollutants in water. In this study, graphitic carbon nitride (g), graphene oxide (GO), and Cobalt ferrite, CoFe 2 O 4 (CF) nanoparticles were synthesized via soft-template-assisted synthesis, Hummer's, and hydrothermal methods, respectively. Subsequently, the hybrid magnetic g-C 3 N 4 /CoFe 2 O 4 /GO (g-CF1@GO, g-CF2@GO, g-CF3@GO, and g-CF4@GO) nanocomposites were prepared via a simple hydrothermal route at 180 °C. The crystallite structure, functional groups, morphology, and energy band gaps were characterized by XRD diffraction, FT-IR, TEM, and UV–vis DRS. The heterostructure nanocomposites were formed, as evidenced by the TEM data, with an average crystallite size of 13.4 nm and band gap energies of 2.19–1.80 eV, suggesting their suitability for sono/photo degradation processes. Pyrene, a tetracyclic polycyclic aromatic hydrocarbon (PAH) was chosen as a model pollutant to evaluate the performance of the prepared nanocomposites toward sonocatalytic degradation. The nanocomposites exhibited higher degradation performances than individual materials. The sonocatalytic degradation of pyrene revealed that the g-CF4@GO nanocomposite exhibited the highest sonocatalytic activity and achieved 86.7 and 92.3 % degradation efficiency for 10 and 5 mg/L of pyrene under ultrasonic irradiation (40 mg/L, 50 W and 20 kHz) in 120 min. In addition, the sonocatalytic degradation of pyrene is performed in the absence of any oxidant and follows a pseudo-first-order kinetics. Trapping experiments were carried out to investigate the sonocatalytic degradation mechanism, and the results showed that ●O 2 − was the major reactive species. The easily recoverable magnetic nanocomposite via a simple magnet was tested for its recyclability and reusability, and it was observed that it could degrade up to 78 % of pyrene in four cycles. [ABSTRACT FROM AUTHOR]

Using cheap and readily available pomelo peel-flesh biomass as raw material to construct ultra-fine and highly dispersed nano-cobalt biochar material, further realizing the efficient activation of peroxymonosulfate to active oxygen species that can effectively degrade organic pollutants, which provides a low-cost way for the elimination of organic pollutants and the continuous purification of sewage. [Display omitted] • A highly dispersed ultrafine nano-Co material was constructed based on pomelo peel-flesh biomass. • Co/BDPPF combined with PMS nearly 100% degradation of tetracycline, and has lasting stability. • Co/BDPPF can efficiently degrade organic pollutants in complex water environments. • The integrated device built by Co/BDPPF can realize the continuous purification of organic sewage. The advanced oxidation process (AOPs) is playing an important role in the elimination of hazardous organic pollutants, but the development of inexpensive and highly active advanced catalysts is facing challenges. In this study, a low-cost and readily available agricultural waste resource pomelo peel-flesh (PPF) biomass was used as the basic raw material, and the uniformly dispersed small cobalt nanoparticles were effectively anchored in the biochar derived from pomelo peel-flesh (BDPPF) by impregnation adsorption/complexation combined with heat treatment. Co/BDPPF (BDPPF embedded with Co) can effectively activate peroxymonosulfate (PMS) to SO 4 ·-, ·OH and 1O 2 reactive oxygen species, and achieve nearly 100% degradation of tetracycline persistent organic pollutant. Co/BDPPF can not only degrade tetracycline efficiently in complex water environment, but also degrade most organic pollutants universally, and has long-term stability, which solves the problem of poor universality and stability of heterogeneous catalysts to a certain extent. Importantly, Co/BDPPF derived from waste biomass was also innovatively designed as the core of an integrated continuous purification device to achieve continuous purification of organic wastewater. In this study, agricultural waste resources were selected as biomass raw materials to achieve efficient capture of Co2+, and finally developed advanced AOPs catalyst with excellent performance to achieve the purification of organic wastewater. It also provides a promising solution for the preparation of simple, low-cost, large-scale production of AOPs catalysts that can be put into actual production. [ABSTRACT FROM AUTHOR]

[Display omitted] • Control of ROS types and ratios based on catalyst structure and component modulation. • Selective degradation of pollutants according to the ratio of different ROSs in the system. • Abundant large pores and open channels are created by confined expansion pore-making strategy. • Possible degradation pathways were proposed by DFT calculations and LC-MS. Selective removal of target organic pollutants in complex water quality of municipal sewage is extremely important for the deep treatment of water quality. Here, energetic MOF and Fe-MOF are doped in electrostatic spinning process to adjust the structure and composition of the catalysts, active oxygen species (ROSs), realizing the selective removal of organic pollutants. Non-azo and azo pollutants are selected as target pollutants. Catalysts PCFe-8 with Fe nanoclusters, EPCFe-8 with Fe-N x , and EPC-8 without Fe doping are used to activate peroxymonosulfate (PMS) for degrading pollutants. The results show that the PCFe-8/PMS system can produce the most SO 4 − and exhibit superior removal of azo pollutants, whereas the degradation behavior of non-azo pollutants is more inclined to occur in the EPCFe-8/PMS system and the EPC-8/PMS system. This work provides a reference for elucidating the relationship between catalyst structure and components, types of ROSs, and selective degradation of pollutants. [ABSTRACT FROM AUTHOR]

A novel type of oxide material, high entropy oxide (Mn0.2Fe0.2Co0.2Ni0.2Cu0.2)3O4 (MFO) composites with spinel structure were successfully synthesized by a simple solution combustion in this paper, and it was first applied to the degradation of antibiotic organic pollutants in water by photo-Fenton. SEM and BET characterization showed that the composite was porous and had a large specific surface area. XPS results showed that Fe, Mn, Cu, Co and Ni all participated in the redox reaction of the catalytic process. The redox pairs of Mn2+/Mn3+, Cu+/Cu2+, Co2+/Co3+, Ni2+/Ni3+ can accelerate the Fe2+/Fe3+ redox cycling in MFO to activate H2O2 and produce more reactive oxygen species. The catalytic performance of MFO composite was investigated using tetracycline hydrochloride (TC-HCl) as a model pollutant. The results displayed that the degradation rate of TC-HCl by MFO was 92.9% when the initial pH was 4, the dose of H2O2 was 50 mM, and the irradiation time was 60 min. The high entropy oxide MFO composites could build up an internal electric field, which restrains electron–hole recombination, improves the transfer of photogenerated charge carriers and maximize photocatalytic property. In addition, the free radical capture experiment determined that the main active species of the degradation reaction were e−, •O2− and •OH. The synergistic effect of the five components in the high entropy oxide strengthens lattice distortion and defects, increases oxygen vacancies, and thus has enhanced catalytic effect for TC-HCl degradation. This work shows that high entropy oxides have excellent catalytic performance for tetracycline organic pollutants, and it is speculated that high entropy oxides have good application prospects in the field of advanced oxidation technology for the degradation of organic pollutants. [ABSTRACT FROM AUTHOR]

Advanced oxysulfur radical-based advanced oxidation processes (OSR-AOPs) usually use heterogeneous catalysts to activate sulfite to degrade organic pollutants in water. In this study, we report the mechanism of sulfite activation by amorphous Fe1−xNixS to degrade rhodamine B (RhB) in different pH ranges. Compared with FeS, Fe1−xNixS had a wide pH application range and high activity. For Fe1−xNixS, Ni-doping sped up electron transfer inside the catalyst and the reduced S2− promoted the ≡Fe(III)/≡Fe(II) cycle, which together improved the sulfite activation by Fe1−xNixS. The results indicated a pH dependence of RhB degradation in the Fe1−xNixS/sulfite system. The free radical pathway of SO3˙−, SO5˙− and ˙OH generated in the process was dominant under acidic condition, whereas it was mainly a non-free radical pathway of electron transfer between the catalyst and the pollutant under alkaline conditions. Both free radical and non-free radical pathways existed in Fe1−xNixS/sulfite under neutral conditions. The results shed significant light on promoting sulfite-based AOPs to remove pollutants from water. [ABSTRACT FROM AUTHOR]

Water pollution is a grave risk to mankind. Water pollutants including organic toxins, dyes effluents, and heavy metals have posed great stress on water quality in recent years. This has necessitated the search for an affordable, eco-friendly, inexpensive, stable, and effective strategy for wastewater remediation. In this work, a pollyoxometallate K6[H2AlBW11O40].9H2O (KAB) was impregnated on kaolin clay to synthesize a clay-based nanocomposite KAB-K which was then evaluated for adsorptive removal of brilliant green dye (BG) from wastewater. The prepared composite was characterized by different techniques such as FTIR, SEM, and EDX analysis. The characterization results indicated the fine distribution of KAB on kaolin's surface. The adsorption studies of BG involved evaluation of optimum parameters such as time contact (30 min), quantity of adsorbent (20 mg), pH (5), temperature (40 °C), and agitation speed (125 rpm). 99.5% of BG was removed by KAB-K within 30 min. The assessment of kinetic data was performed via Langmuir, Freundlich, and Temkin models. The experimental data was found to be in good agreement with the Langmuir model (R2 > 0.9965) as compared to other models. Qmax value of KAB-K (144.92 ± 0.005 mg/g) was much higher than simple kaolin (33.22 ± 0.01 mg/g). The applicability of the pseudo-second-order kinetic model suggested that the process was predominately chemisorption. KAB-K was easier to recycle and efficiently removed up to 68.7% dye in 3 subsequent cycles. Thus rapid adsorption rate, high adsorption capacity, efficient recovery, and reusability of KAB-K endorses that the synthesized composite is an effective adsorbent for wastewater pollutants. [ABSTRACT FROM AUTHOR]

Monitoring organic pollutants in rainwater is important to understand relations between air pollutants and water safety. Non-targeted liquid chromatography–mass spectrometry (LC–MS) is a powerful tool but because of big differences of pollutants in polarity, ionization efficiency, and low concentrations, it is challenging to detect all pollutants in a single analysis. Chemical derivatization is a widely adapted strategy to fractionate complex samples with enhanced sensitivity and selectivity. Herein, we propose the usage of dansylation as a chemical derivatization method to improve both LC retention and MS ionization of organic pollutants containing amine, hydroxyl, and carboxyl for non-targeted LC–MS analysis. We first evaluated the labeling coverage of dansylation to organic pollutants in water matrix. Using dansyl chloride (DnsCl) and dansyl hydrazine (DnsHz) to label 100 amine- and hydroxyl-containing compounds and 100 carboxyl compounds, respectively, we found DnsCl and DnsHz had over 60% labeling coverage for 8 categories of compounds. Then dansylation was applied to label the rainwater, source water, disinfected rainwater, and drinking water samples. To facilitate the annotation of dansylated compounds, we also established a web-based tool termed DansylFinder. Using DansylFinder, 3889, 5813, 6077, and 4050 tentative annotations were found in rainwater, source water, disinfected rainwater, and drinking water samples by dansylation-based non-targeted LC-HRMS analysis. Four hundred fifty four were persistently detected in all water samples, suggesting significant organic overlaps of the four water samples. In addition, two degradation pathways reported in drinking water disinfection process were also detected in disinfected rainwater, suggesting rainwater is a potential path for air pollutants to infiltrate drinking water system. [ABSTRACT FROM AUTHOR]

AbstractWater resources are precious resources around the world, but pollution is becoming increasingly severe. While the degree of damage to water caused by organic pollutants is reflected by chemical oxygen demand, which is also an important indicator for hydrological monitoring. Therefore, accurate measurement of chemical oxygen demand is necessary. The rapid development of water quality detection by ultraviolet visible spectrum analysis as an efficient, convenient, and pollution-free new water quality detection method has been achieved. When we were processing ultraviolet visible spectral absorbance data, various environmental factors can affect the chemical oxygen demand light absorption value, thus affecting the accuracy of detection. So there are some goals, such as more comprehensively extracting the feature wavelength and reducing the interference to achieve better detection results. It is expected that the model can be applied to a portable water quality detection device. It is necessary to consider detection time, reduce model training parameters, and improve detection speed. Therefore, this article proposes Competitive Adaptive Weighted Sampling-Convolutional Neural Network-Long Short-Term Memory and Competitive Adaptive Weighted Sampling-Convolutional Long Short-Term Memory models for detecting chemical oxygen demand in water. To verify the effectiveness of the proposed model, the model was trained on the experimental dataset and the detection results of all models involved in the article were compared. It can be confirmed that the application of these two proposed algorithms results in less detection time and higher accuracy in concentration detection. [ABSTRACT FROM AUTHOR]

Au@Ag core--shell composites were successfully fabricated on urchinlike covalent organic frameworks (COFs), providing a platform with numerous hot spots for the detection of two categories of emerging contaminants: sulfonamide antibiotics and nanoplastics, using surfaceenhanced Raman spectroscopy (SERS). Au seeds (~10 nm) were generated on the COFs, leveraging the reducing properties of the vinyl and imino groups within the framework. This ensured the growth of dense and uniformly distributed Ag nanoparticles. The COFs exceptionally large surface area (2324 m² g-1) and high adsorption capacity, significantly contributed to the enrichment and detection of trace pollutants. As a result, using a portable Raman spectrometer, limits of detection of 0.008 lmol L-1 for sulfamethoxazole and 0.029mg L-1 for polystyrene nanoplastics were achieved. [ABSTRACT FROM AUTHOR]

The remediation of polluted water is a major concern for public health and the environment. Catalytic removal of model organic and inorganic pollutants in water using carbon catalysts has shown promising results. In the present work, stereolithographically 3D‐printed bio‐based carbon monoliths with different textural and surface chemistry properties were used as catalysts for oxalic acid oxidation and catalyst supports for bromate reduction in continuous systems. A significant synergistic effect between ozone or dihydrogen and carbon catalyst was evidenced by mineralization of 14–25 % of oxalic acid or reduction of 15–45 % of bromates in the steady state, respectively. The best results were achieved with samples with the highest mesoporous surface area or, in the case of lower surface area, with samples having the strongest basic character. As materials with great potential, optimizing the textural properties of architected carbon monoliths will enable them to compete with other macro‐structured carbon catalysts. [ABSTRACT FROM AUTHOR]

Industrial discharge of hazardous organic and synthetic chemicals, such as antibacterials and dyes, poses severe risks to human health and the environment. This study was conducted to address the urgent need for efficient and stable zinc-oxide-based photocatalysts to degrade such pollutants. A novel approach to synthesizing silver-loaded zinc oxide (Ag@Z) catalysts was introduced by using a simple and efficient combination of hydrothermal and precipitation methods. Comprehensive characterization of Ag@Z photocatalysts was performed using XRD, XPS, Raman, UV–vis adsorption, FTIR, and SEM, revealing an enhancement of structural, optical, and morphological properties in comparison to pure zinc oxide. Notably, the 5%Ag@Z catalyst exhibited the highest degradation efficiency among the other synthesized catalysts under UV-C light irradiation, and enhanced the degradation rate of pure zinc oxide (Z) by 1.14 and 1.64 times, for Triclosan (TCS) and Methylene Blue (MB), respectively. the effect of catalyst dose and initial concentration was studied. A mechanism of degradation was proposed after investigating the effect of major reactive species. The 5%Ag@Z catalyst increased the photostability, which is a major problem of zinc oxide due to photocorrosion after reusability. We found that 50% and 74% of energy consumption for the photocatalytic degradation of TCS and MB by 5%Ag@Z, respectively, was saved in compassion with zinc oxide. The remarkable photocatalytic performance and the good recovery rate of Ag@Z photocatalysts demonstrate their high potential for photocatalytic degradation of organic contaminants in water. [ABSTRACT FROM AUTHOR]

Acid mine drainage (AMD) is one of the main environmental problems associated with mining activity, whether the mine is operational or abandoned. In this work, several precipitates from this mine drainage generated by the oxidation of sulfide minerals, when exposed to weathering, were used as adsorbents. Such AMD precipitates from abandoned Portuguese mines (AGO, AGO-1, CF, and V9) were compared with two raw materials from Morocco (ClayMA and pyrophyllite) in terms of their efficiency in wastewater treatment. Different analytical techniques, such as XRD diffraction (XRD), Fourier Transform Infrared spectroscopy (FTIR), N2 adsorption isotherms, and Scanning Electron Microscopy (SEM) with Energy Dispersive X-ray (EDX) were used to characterize these natural materials. The adsorption properties were studied by optimizing different experimental factors, such as type of adsorbent, adsorbent mass, and dye concentration by the Box–Behnken Design model, using methylene blue (MB) and crystal violet (CV) compounds as organic pollutants. The obtained kinetic data were examined using the pseudo-first and pseudo-second order equations, and the equilibrium adsorption data were studied using the Freundlich and Langmuir models. The adsorption behavior of the different adsorbents was perfectly fitted by the pseudo-second order kinetic model and the Langmuir isotherm. The most efficient adsorbent for both dyes was AGO-1 due to the presence of the cellulose molecules, with qm equal to 40.5 and 16.0 mg/g for CV and MB, respectively. This study confirms the possibility of employing AMD precipitates to adsorb organic pollutants in water, providing valuable information for developing future affordable solutions to reduce the wastes associated with mining activity. [ABSTRACT FROM AUTHOR]

[Display omitted] • Co 2 Mn-LDH efficiently activates CaSO 3 for rapid degradation of MNZ. • Co 2 Mn-LDH exhibits superior stability and reusability in the degradation process. • SO 4 •− and 1O 2 are the major radicals in MNZ degradation process. • The redox cycle of Co2+/Co3+ and Mn3+/Mn4+, and O v enhance the ROS generation. • Co 2 Mn-LDH/CaSO 3 system shows excellent anti-resistance to water matrix. Metronidazole (MNZ), a commonly used antibiotic, poses risks to water bodies and human health due to its potential carcinogenic, mutagenic, and genotoxic effects. In this study, mesoporous cobalt-manganese layered double hydroxides (Co x Mn y -LDH) with abundant oxygen vacancies (O v) were successfully synthesized using the co-precipitation method and used to activate calcium sulfite (CaSO 3) with slight soluble in water for MNZ degradation. The characterization results revealed that Co 2 Mn-LDH had higher specific areas and exhibited good crystallinity. Co 2 Mn-LDH/CaSO 3 exhibited the best catalytic performance under optimal conditions, achieving a remarkable MNZ degradation efficiency of up to 98.1 % in only 8 min. Quenching experiments and electron paramagnetic resonance (EPR) tests showed that SO 4 •− and 1O 2 played pivotal roles in the MNZ degradation process by activated CaSO 3 , while the redox cycles of Co2+/Co3+ and Mn3+/Mn4+ on the catalyst surface accelerated electron transfer, promoting radical generation. Three MNZ degradation routes were put forward based on the density functional theory (DFT) and liquid chromatography-mass spectrometer (LC-MS) analysis. Meanwhile, the toxicity analysis result demonstrated that the toxicity of intermediates post-catalytic reaction was decreased. Furthermore, the Co 2 Mn-LDH/CaSO 3 system displayed excellent stability, reusability, and anti-interference capability, and achieved a comparably high removal efficiency across various organic pollutant water bodies. This study provides valuable insights into the development and optimization of effective heterogeneous catalysts for treating antibiotic-contaminated wastewater. [ABSTRACT FROM AUTHOR]

With the abuse of antibiotics, its pollution poses an increasing threat to the environment and human health. Effective degradation of organic pollutants in water bodies is urgent. Compared to traditional treatment methods, advanced oxidation processes that have developed rapidly in recent years are more environmentally friendly, efficient and applicable to a wider range of organic compounds. FeWO4 was used in this study as the iron-based semiconductor material to modify and optimize the material design. Fe3O4/FeWO4 composites were prepared by a two-step hydrothermal method. The crystal structure, surface morphology, electrochemical properties and separability of the composite semiconductor were analyzed by XRD, XPS, UV-vis, SEM, EDS and Mott-Schottky. The results showed that, when the initial contaminant concentration was 30 mg/L, the initial solution pH was 4, the dosage of the catalyst was 25 mg and the dosage of hydrogen peroxide was 30 μL, the degradation efficiency of tetracycline hydrochloride (TCH) could reach 91% within 60 min, which was significantly improved compared to the performance of the single semiconductors Fe3O4 and FeWO4. In addition, the catalyst prepared in this experiment can be easily recovered by magnetic separation technology in practical application, which will not affect the turbidity of water while reducing the cost of catalyst separation and recovery. [ABSTRACT FROM AUTHOR]

This article discusses the practical applications of nanoparticles (NPs) in various fields, such as medicine, cosmetics, catalysis, and environmental protection. The properties of NPs are influenced by their size, shape, and composition, and their use in catalysis can greatly enhance their activity and efficiency. This special issue focuses specifically on the application of NPs in catalysis for environmental protection, including processes such as the oxidation of volatile organic compounds, hydrogen production, CO2 reduction, wastewater treatment, and soot oxidation. The article expresses gratitude towards the reviewers and authors who contributed to the special issue, acknowledging their time and effort in reviewing the papers and appreciating the high-quality research and review papers submitted. [Extracted from the article]

Cobalt nanoferrite CoFe2O4 (NFCo) was synthesized using the sol–gel auto-combustion method. The structural, morphology, and magnetic properties were characterized. X-ray diffraction analysis revealed the formation of a pure phase with an inverse spinel structure, featuring an average crystallite size of 67 nm. Scanning electron microscopy observations revealed the existence of particle agglomerates and a porous morphology. The spinel structure was confirmed by Raman spectroscopy, with the identification of the five characteristic modes (A1g (1), Eg, T2g (3), T2g (2), T2g (1)), as well as by FTIR spectroscopy, where the two vibrational modes in the tetrahedral and octahedral sites (576.8 and 412.12 cm−1) were observed. Magnetic analysis revealed that the coercive field increased resistance to demagnetization. Various oxidation processes, including UV, plasma-activated water (PAW) by gliding arc discharge (GAD), and NFCo, as well as hybrid systems UV, PAW/UV, NFCo/UV, PAW/NFCo, and PAW/NFCo/UV, were employed to assess the elimination of AG25 dye. Decolorization processes, mechanisms, and photocatalysis were studied. The effect of experimental parameters as a function of time, pH, and UV exposure showed that the maximum decolorization rate was 56.1% with PAW alone, 73.1% with PAW/UV, 72.4% with PAW/NFCo, and 99.1% with PAW/NFCo/UV after 360 min. The effect of pH demonstrated that the treatment is more effective under acidic conditions (pH = 2), achieving a decolorization rate of 75.6% in just 60 min, compared to neutral and alkaline conditions. This study underscores the potential of NFCo combined with plasma-activated water and UV as magnetic nanophotocatalysts to replace classical heterogeneous catalysts in water treatment, offering new perspectives for more effective methods of degrading organic pollutants in water treatment applications. [ABSTRACT FROM AUTHOR]

Adsorption energies obtained from dispersion‐corrected density functional theory (DFT) calculations show a considerable dependence on the choice of exchange‐correlation functional and dispersion correction. A number of investigations have employed different approaches to compute adsorption energies of small molecules in zeolites, using reference values from high‐level calculations and/or experiments. Such comparative studies are lacking for larger functional organic molecules such as pharmaceuticals or personal care products, despite their potential relevance for applications, e. g., in contaminant removal or drug delivery. The present study aims to fill this gap by comparing adsorption energies and, for selected cases, equilibrium structures of emerging organic contaminants adsorbed in MOR‐ and FAU‐type all‐silica zeolites. A total of 13 dispersion‐corrected DFT approaches are compared, including methods using a pairwise dispersion correction as well as non‐local van der Waals density functionals. While absolute values of adsorption energies vary widely, qualitative trends across the set of zeolite‐guest combinations are not strongly dependent on the choice of functional. For selected cluster models, DFT adsorption energies are compared to reference values from coupled cluster (DLPNO‐CCSD(T)) calculations. Although all DFT approaches deliver systematically more negative adsorption energies than the coupled cluster reference, this tendency is least pronounced for the rev‐vdW‐DF2 functional. [ABSTRACT FROM AUTHOR]

This study aims to improve the photocatalytic activity of TiO2 in removing organic contaminants from water. The practical use of TiO2 nanopowder is restricted due to issues related to catalyst recovery and reuse. The study investigates supporting TiO2 on natural clay (Kaolin) for phenazopyridine's photodegradation to address this issue. A series of experiments were carried out, looking at TiO2 supported on clay and unsupported TiO2 (both anatase and rutile phases), while also taking into account N-doping, annealing temperature, and pH values. The outcomes demonstrated that rutile TiO2/Clay (R-TiO2/Clay) exhibited the highest catalytic efficiency, capable of removing up to 90% of phenazopyridine within just 60 min under particular circumstances. It is interesting that the ideal pH for this process was discovered to be 8.7, or roughly equal to the natural surface water pH value which is ranged 6.5–8.5. The optimal photocatalyst annealing temperature was 500 °C, and the optimal photodegradation temperature was 35 °C. Furthermore, catalyst recovery and reuse tests indicated sustained efficiency over four cycles, highlighting its durability. High-performance liquid chromatography, total organic carbon, and elemental analysis validated phenazopyridine's complete breakdown and mineralization. This study emphasizes the significance of supporting TiO2 on clay to improve its photocatalytic activity and circumvent the drawbacks of its nanopowder form, in addition to the clay's synergistic effect due to the acceptable amount of ZnO present in the clay composition, which participates in the photodegradation of phenazopyridine. Due to its wide availability and thermal stability, this composite holds significant potential for water purification and environmental remediation. [ABSTRACT FROM AUTHOR]

In this research, the efficiency of degradation of different organic contaminant classes, including pesticides (tembotrione, clomazone), pharmaceuticals (ciprofloxacin, 17α-ethinyl estradiol) and mycotoxins (zearalenone, deoxynivalenol, fumonisin B1) with subcritical water treatment was studied in model systems. All experiments were conducted in a house-made batch-type pilot reactor. The research was focused on the optimization of the treatment parameters using moderate treatment conditions. Optimization of the remediation processes of water contaminated with 17α-ethinyl estradiol, tembotrione, clomazone, and ciprofloxacin, was conducted through testing with different homogeneous and heterogeneous catalysts, as well as different gas atmospheres (nitrogen and carbon dioxide) for pressurization of the process system. Mycotoxins in water were degraded without catalysts and all experiments were conducted in nitrogen atmosphere. Optimization was conducted through defining the optimal combination of the treatment temperature and time, oriented towards energy saving and minimization of the technical requirements. The degradation efficiency in all tested samples was determined via HPLC analysis. Study showed the full degradation of tembotrione and all tested mycotoxins at 200 °C without a need for a catalyst. The efficiency of degradation of other tested pollutants at 200 °C was satisfying and within the range of 89.5% (clomazone) to 98.7% (17α-ethinyl estradiol). [ABSTRACT FROM AUTHOR]

A new core-shell structure CdS@Fe2S3 material was synthesized by in situ cation exchange method to enhance the degradation of organic pollutants in water under visible light. It is proved that Fe2S3 nanolayer is successfully loaded on CdS nanorods by TEM and UV-Vis spectra and other means. The representative Rhodamine B was selected as the target pollutant and the results of degradation experiment showed that after 60 min of exposure to LED visible light with a low energy (25 W), the removal efficiency for this dye could reach 98 % in the presence of peroxymonosulfate (PMS) forming free radicals, which displayed a observed kinetic rate constant exceeding 0.62 min-1 that is approximately 5 times higher than the system without PMS addition and 10 times than the system with original CdS as catalyst. The result of inhibition experiments shows that sulfate radical (SO4·-) and singlet oxygen ( ¹O2) play as important roles during the photocatalytic process. In addition, this coreshell material can be recycled at least four times. Generally, this study can make full use of visible light which can be easily obtained and effectually resolve the organic pollution problems. [ABSTRACT FROM AUTHOR]

[Display omitted] Photocatalysis is a promising sustainable technology to remove organic pollution and convert solar energy into chemical energy. Titanium dioxide has drawn extensive attention in this field owing to its high activity under UV light, good chemical stability, large availability, low price and low toxicity. However, the poor quantum efficiency derived from fast electron/hole recombination, the limited utilization of sunlight, and a weak reducing ability still hinder its practical application. Among the modification strategies of TiO 2 to enhance its performance, the construction of heterojunctions with other semiconductors is a powerful and versatile way to maximise the separation of photogenerated charge carriers and steer their transport toward enhanced efficiency and selectivity. Here, the research progress and current status of TiO 2 modification are reviewed, focusing on heterojunctions. A rapid evolution of the understanding of the different charge transfer mechanisms is witnessed from traditional type II to the recently conceptualised S-scheme. Particular attention is paid to different synthetic approaches and interface engineering methods designed to improve and control the interfacial charge transfer, and several cases of TiO 2 heterostructures with metal oxides, metal sulfides and carbon nitride are discussed. The application hotspots of TiO 2 -based photocatalysts are summarized, including hydrogen generation by water splitting, solar fuel production by CO 2 conversion, and the degradation of organic water pollutants. Hints about less studied and emerging processes are also provided. Finally, the main issues and challenges related to the sustainability and scalability of photocatalytic technologies in view of their commercialization are highlighted, outlining future directions of development. [ABSTRACT FROM AUTHOR]

• The Fenton-like Cu-PAN 3 catalysts is first synthesized by co-precipitation and carbon thermal reduction method. • Dual reaction centers are constructed around graphene-like carbon and Cu species. • The pollutants as electron donors inhibit the ineffective decomposition of H 2 O 2 at the electron-poor centers. • The pollutant removal mainly relies on the surface cleavage at the electron-poor centers. High energy consumption has seriously hindered the development of Fenton-like reactions for the removal of refractory organic pollutants in water. To solve this problem, we designed a novel Fenton-like catalyst (Cu-PAN 3) by coprecipitation and carbon thermal reduction. The catalyst exhibits excellent Fenton-like catalytic activity and stability for the degradation of various pollutants with low H 2 O 2 consumption. The experimental results indicate that the dual reaction centers (DRCs) are composed of Cu-N-C and Cu-O-C bridges between copper and graphene-like carbon, which form electron-poor/rich centers on the catalyst surface. H 2 O 2 is mainly reduced at electron-rich Cu centers to free radicals for pollutant degradation. Meanwhile, pollutants can be oxidized by donating electrons to the electron-poor C centers of the catalyst, which inhibits the ineffective decomposition of H 2 O 2 at the electron-poor centers. This therefore significantly reduces the consumption of H 2 O 2 and reduces energy consumption. [Display omitted] [ABSTRACT FROM AUTHOR]

The rising energy demand via renewable sources and existence of organic pollutants in water has attracted the world-wide attention to attain sustainable ecosystems. The development of a multi-functional catalyst with significant economic and environmental implications remains a challenge. Herein, we synthesized SnS 2 /g-C 3 N 4 hierarchical nanoflower using solvothermal method, verified by XRD and FTIR investigations. The surface morphology was analyzed using FESEM, TEM and HRTEM while optical absorption via UV–Vis spectroscopy. SnS 2 /g-C 3 N 4 displayed outstanding electrocatalytic activity for HER and OER with smaller tafel slope and higher values of current density. The results are in accordance with C dl and ECSA values, ensuing more active sites and surface area for a catalytic reaction to take place. As-prepared SnS 2 /g-C 3 N 4 also exhibited 90 % photocatalytic MB deterioration in 90 min upon solar irradiation, following first order kinetics. Type-II mechanism for charge transfer alongwith reactive specie trapping experiment and cyclic stability is also presented. The findings suggests that SnS 2 /g-C 3 N 4 emerged as proficient catalyst for electrocatalytic and photocatalytic applications. [Display omitted] [ABSTRACT FROM AUTHOR]

Comprehensive strategies with the development of advanced materials are required for the remediation of water and land pollution to protect the environment and human health. In this regard, iron oxide catalysts are recognized as preferable catalysts for the heterogeneous photo-Fenton process, which is an efficient technique for degrading organic pollutants in waste water. The present study discusses the photocatalytic performance of iron oxide-based catalysts synthesized from industrial waste red mud for methylene blue degradation under visible light irradiation. XRD studies confirmed the formation of a pure α-Fe2O3 (hematite) phase, whereas the doping of iron oxide with Mn, Cu, and Ce was ascertained by XPS analysis. 3 wt% Cu doped iron oxide with a TOC value of ∼84.7% showed the best removal efficacy to the tune of ∼91% within 60 min of visible light irradiation. Impedance data supports the enhanced charge separation in metal doped α-Fe2O3, which improves the photocatalytic performance. A similar trend was observed in photo-electrochemical (PEC) properties, where Cu doped Fe2O3 showed 2 times higher photocurrent than the bare one. Based on scavenging tests, electrons and hydroxyl radicals (˙OH) were shown to be major players in the photodegradation of pollutants under visible light. A probable mechanism explaining the enhanced e−/h+ pair separation and migration was proposed by examining electrochemical properties. This work has significant implications for wastewater treatment with the efficient use of industrial waste red mud as a cost-effective resource. [ABSTRACT FROM AUTHOR]

In environmental chemistry, photocatalysts for eliminating organic contaminants in water have gained significant interest. Our study introduces a unique heterostructure combining MIL-101(Cr) and bismuth oxyiodide (Bi5O7I). We evaluated this nanostructure's efficiency in adsorbing and degrading tetracycline (TC) under visible light. The Bi5O7I@MIL-101(Cr) composite, with a surface area of 637 m2/g, prevents self-aggregation seen in its components, enhancing visible light absorption. Its photocatalytic efficiency surpassed Bi5O7I and MIL-101(Cr) by 33.4 and 9.2 times, respectively. Comprehensive analyses, including scanning electron microscopy (SEM) and transmission electron microscopy (TEM), confirmed the successful formation of the heterostructure with defined morphological characteristics. BET analysis demonstrated its high surface area, while X-ray diffraction (XRD) confirmed its crystallinity. Electron spin resonance (ESR) tests showed significant generation of reactive oxygen species (ROS) like h+ and·•O2− under light, crucial for TC degradation. The material maintained exceptional durability over five cycles. Density functional theory (DFT) simulations and empirical investigations revealed a type I heterojunction between Bi5O7I and MIL-101(Cr), facilitating efficient electron–hole pair separation. This study underscores the superior photocatalytic activity and stability of Bi5O7I@MIL-101(Cr), offering insights into designing innovative photocatalysts for water purification. [ABSTRACT FROM AUTHOR]

Detection and removal of trace amounts of toxic organic and inorganic pollutants in water and wastewater is important for the entire ecosystem. The development of new materials for the determination and removal of contaminants is constantly necessary. Layer double- hydroxides (LDHs) form a broad class of nanomaterials that represent anionic clay composite material used in research and development applications to protect the environment from pollutants. LDH structures functionalized with carbon-based materials are promising adsorbents in the extraction of organic and inorganic pollutants through adsorption and ion exchange mechanisms due to their increased versatility. This review describes recent studies on carbon-containing structure-based LDH composites used in the determination and removal of organic and inorganic pollutants in water and wastewater. Thus, it will lead to the realization of new studies for the determination and removal of different pollutants in other matrices besides water samples of LDHs. [ABSTRACT FROM AUTHOR]

[Display omitted] • Rare [Cu 4 I 2 ]2+ cationic cluster constructs a novel 3D Cu(I)-MOF. • The stable Cu(I)-MOF shows sensitive detection ability for ROX, NFZ and NFT. • Hierarchical porous Cu(I)-MOF/MF composites were built by a one-pot method. • The Cu(I)-MOF/MF exhibits remarkable adsorption capacity towards ROX, NFZ and NFT. Fluorescence quenching induced by photoinduced electron transfer (PET) stands as an effective strategy for identifying water pollutants. Herein, a novel (4, 8)-connected three-dimensional framework Cu(I)-MOF ([Cu 2 I(tpt)] n) with unique 8-connected [Cu 4 I 2 ]2+ cationic clusters is designed by employing the nitrogen-rich ligand (Htpt = 5-[4(1 H -1,2,4-triazol-1-yl)]phenyl-2 H -tetrazole). Water-stabilized Cu(I)-MOF exhibits outstanding fluorescence properties, facilitating its application in detecting organic pollutants in water. Benefiting from the fact that the Cu(I)-MOF possesses a higher lowest unoccupied molecular orbitals (LUMO) energy level than that of the analyte, the rapid d-PET can occur, entitling Cu(I)-MOF to a sensitive fluorescence quenching response to roxarsone (ROX), nitrofurazone (NFZ) and nitrofurantoin (NFT) (with detection limits as low as 0.13 µM, 0.15 µM, and 0.13 µM, respectively). The nitrogen-containing sites of melamine foam (MF) are utilized to facilitate the anchoring and growth of Cu-MOF crystals, which enables the preparation of hierarchical microporous − macroporous Cu(I)-MOF/MF composites. The ordered porous structure of Cu(I)-MOF/MF provides cavities and open sites for the efficient removal of ROX (q max = 210.6 mg∙g−1), NFZ (q max = 111.5 mg∙g−1) and NFT (q max = 238.9 mg∙g−1) from water. This characteristic endows the Cu(I)-MOF/MF with rapid and recyclable adsorption capacity. Therefore, this work provides valuable insights to address the problem of detection and removal of pollutants in the aquatic environment. [ABSTRACT FROM AUTHOR]

Recently, there has been considerable interest in developing an efficient, easily separable, cost-effective, and environmentally friendly catalyst for treating toxic environmental pollutants. In this study, we successfully designed yttrium–nickel-doped magnetite nanowires (Y 0.045 Ni 0.045 Fe 2.91 O 4) and their mesoporous silica (MS)-coated composite (Y 0.045 Ni 0.045 Fe 2.91 O 4 / MS) using a simple coprecipitation method. The resulting composite demonstrated effective adsorption and photocatalytic degradation of crystal violet (CV) dye under sunlight. Various instrumental characterization techniques were employed to assess the nanowires' morphological, chemical, and surface functional properties and their composite. The existence of metal–oxygen bonds in Y 0.045 Ni 0.045 Fe 2.91 O 4 within the 500–800 cm−1 range was verified through FTIR analysis. According to the Brunauer–Emmett–Teller analysis, the composite exhibited a surface area of 285 m2/g, a pore volume of 0.436 cm³/g, and an average pore width of 5 nm. The composite's high surface area and mesoporous nature underscored its porous structure, confirming its enhanced adsorption capacity for contaminants. High resolution XPS spectrum justified the presence of surface silanol groups (Si–OH) which are responsible for adsorption phenomena. Photocatalytic experiments revealed that Y 0.045 Ni 0.045 Fe 2.91 O 4 nanowires and their composites achieved 89% and 90% degradation rates for CV dye within 60 and 10 min, respectively. The removal efficiency was assessed under optimized conditions of pH (8), dose (15 mg), time (60 and 10 min), and concentration (10 mg/L). Statistical analysis revealed that pH significantly impacted CV dye removal because functional group activation varied at different pH values. To elucidate the adsorption mechanism and kinetics, the Temkin isotherm model and pseudo-second-order kinetics model (R2 = 1.996 mg min−1) were the best fit for the composite. Furthermore, approximately 99% of the nanowires were magnetically separated from the reaction mixture in an external magnetic field. The demonstrated synergy of efficient adsorption–photocatalysis, coupled with easy recovery, suggests that innovatively designed nanomaterials are optimal for the water remediation of organic pollutants in wastewater. [ABSTRACT FROM AUTHOR]

Low-concentration antibiotic wastewater is difficult to treat rapidly using conventional photocatalysts. For this reason, this paper simplified the traditional sol–gel method to prepare Fe3+-TiO2/AC composites and characterized the properties of the composites using FT-IR, XRD, SEM, BET, and TEM. The results demonstrated that iron was uniformly dispersed on the surface of the composites, and the activated carbon (AC) was successfully loaded with iron-doped titanium dioxide. Afterward, ciprofloxacin (CIP) was used as the target degradant, and the effects of different activated carbon loadings, iron-doping, pH, initial concentrations, and UV light intensities on the removal of ciprofloxacin were investigated. The repetitive photocatalytic stability of the composites was studied, and the reaction mechanism was explored by using free radical quenching experiments. The results demonstrated that while iron doping reduced the rate at which photogenerated electrons and holes could combine, loading AC increased the usage efficiency of the composites' adsorption and catalytic active sites. According to the parameter tests, the circumstances that led to the highest CIP degradation efficiency (94.59%) were as follows: 10 mg/L CIP, 0.5 g/L 0.2%Fe3+-TiO2/20%AC, and solution pH of 7 under 40 min of UV light irradiation. In addition, the Fe3+-TiO2/AC composite material has excellent cyclic stability, the degradation rate of CIP can still reach 87.73% at 60 min after four repeated degradation tests under the same conditions. The applicability of this method could be expanded to the treatment of various industrial organic pollutants in water. [ABSTRACT FROM AUTHOR]

The scientific community has preferred the photocatalysis process to remove organic pollutants from water. Many catalysts have been developed over the years, and one such catalyst is molybdenum disulfide (MoS2), which is a two-dimensional (2D) material with an energy bandgap in the visible spectrum. In this manuscript, the facile synthesis of MoS2 nanostructures in varying molybdenum (Mo) and sulphur (S), Mo/S ratios has been demonstrated through a single-pot hydrothermal route. The structural validation of the nanostructures was done using X-ray diffraction (XRD) patterns. Further, the morphological information about the MoS2 nanostructures was gathered using the Field Emission Scanning Electron Microscope (FE-SEM) and High-Resolution Transmission Electron Microscope (HR-TEM) analyses. The photodegradation process of the Malachite Green dye was analyzed by UV-visible absorption spectroscopy. The results showed that 1T/2H MoS2 nanoflowers degraded the malachite green dye with a degradation efficiency of 98.4%. The decomposition of this commonly used dye possesses great significance in industrial waste water treatment. [ABSTRACT FROM AUTHOR]

Anodic oxidation is a promising method for removing organic pollutants from water due to its high nonselectivity and effectiveness. Nevertheless, its widespread application is limited due to its low current efficiency, high energy consumption and low treatment rates. These problems may be overcome by the optimization of the process parameters, reactor design and electrode geometry, by coupling the experimental investigations with mathematical modeling. Here we review the modeling of anodic oxidation with focus on basics of this process, the competition phenomenon in real wastewater, flow cells and batch cells, historical aspects, general modeling equations, modeling with plate electrodes, modeling with porous 3-dimension electrodes and the density functional theory. Mathematical modeling can provide current, voltage and concentration distributions in the system. Mathematical modeling can also determine the effects on the performance of parameters such as diffusion layer thickness, flow velocity, applied current density, solution treatment time, initial concentration and diffusion coefficients of organic pollutants, electrode surface area, and oxidation reaction rate constant. Mathematical models allow to determine whether the limiting factor of the process is kinetics or diffusion, and to study the impact of competition of phenomena. The density functional theory provides information on probable reaction pathways and by-products. [ABSTRACT FROM AUTHOR]

The removal of pesticides and other organic pollutants from water through advanced oxidation processes (AOPs) holds great promise. The main advantage of these technologies is that they remove, or at least reduce, pesticide levels by mineralization rather than transfer, as in conventional processes. This study first evaluated the effectiveness of UV/S2O8= compared to heterogeneous photocatalysis using UV/TiO2 processes on the degradation of two commonly used herbicides (terbuthylazine and isoproturon) in aqueous solutions using a laboratory photoreactor. In addition, the effect of the UV wavelength on the degradation efficiency of both herbicides was investigated. Although the degradation rate was greater under UV(254)/S2O8= nm than under UV(365)/S2O8= nm, complete degradation of the herbicides (0.2 mg L−1) was achieved within 30 min under UV-366 nm using a Na2S2O8 dose of 250 mg L−1 in the absence of inorganic anions. To assess the impact of the water matrix, the individual and combined effects of sulfate (SO4=), bicarbonate (HCO3−), and chloride (Cl−) were evaluated. These can react with hydroxyl (HO•) and sulfate (SO4•−) radicals generated during AOPs to form new radicals with a lower redox potential. The results showed negligible effects of SO4=, while the combination of HCO3− and Cl− seemed to be the key to the decrease in herbicide removal efficiency found when working with complex matrices. Finally, the main intermediates detected during the photodegradation process are identified, and the likely pathways involving dealkylation, dechlorination, and hydroxylation are proposed and discussed. [ABSTRACT FROM AUTHOR]

The graphitic carbon nitride (g-C3N4) has garnered significant attention in the past decade as a highly promising material for water splitting and organic pollutants (dye) degradation. In the present work, we synthesized the three different nano-scaled g-C3N4 samples with urea and thiourea in different weight ratios using the polycondensation method. The X-ray diffraction studies revealed that all the samples have shown the crystalline structure of g-C3N4 with two fundamental diffraction peaks of (002) and (100). The nano-scale nature of the sample is confirmed by Scanning electron microscopy (SEM). The band gap energy was also estimated for all the samples using Tauc plots. The synthesized materials have been used for dye degradation of methylene blue, Phenol red, and Coomassie brilliant blue. Among the three samples, the equal weight ratio of urea and thiourea sample shows the highest degradation of 53%, 45%, and 59% of methylene blue, Phenol red, and Coomassie brilliant blue respectively within 30 min time. Further, we have also reported the dye degradation with the effect of catalyst mass and time of UV light exposure. [ABSTRACT FROM AUTHOR]

[Display omitted] The development of stable and efficient heterojunction photocatalysts for wastewater environmental purification exhibits a significant challenge. Herien, a promising binary heterojunction complex comprising boron subphthalocyanine bromide/bismuth oxychloride (SubPc-Br/BiOCl) was successfully synthesized using the hydrothermal method, which involved the self-assembled of SubPc-Br on the surface of BiOCl via intermolecular π-π stacking interactions to compose an electron-transporting layer. The photocatalytic efficiency of SubPc-Br/BiOCl for the degradation of tetracycline and the minocycline exhibited a substantial improvement of 29.14% and 53.72%, respectively, compared to the original BiOCl. Experimental characterization and theoretical calculations elucidated that the enhanced photocatalytic performance of the SubPc-Br/BiOCl composite photocatalysts stemmed from the S-scheme electron transport mechanism at the interface between BiOCl and SubPc-Br supramolecules, which broadened the visible light absorption range, increased the carrier molecular efficiency, and accelerated the carriers. Furthermore, molecular dynamic (MD) simulations provided insights into the action trajectories of the two semiconductors, revealing that the presence of SubPc-Br enhances the water and organic pollutant adsorption capabilities of the BiOCl surface within the supramolecular array system. In conclusion, the synthesis and analysis of the binary heterojunction complex SubPc-Br/BiOCl yield valuable insights into the efficient photocatalytic degradation of antibiotics, holding great promise for diverse environmental applications. [ABSTRACT FROM AUTHOR]

Hydrotalcite/bismuth solid solution (2D/2D CoAl-LDH/BiO(OH)XI1−X) heterojunction photocatalysts were fabricated through a hydrothermal route. Because of their identical layered structure and interlayer hydroxides, CoAl-LDH(2D) and BiO(OH)XI1−X(2D) form a tightly bonded heterojunction, resulting in efficient light absorption, excitation, and carrier migration conversion. At the same time, the large specific surface area and abundant hydroxyl groups of the layered structure make the heterojunction catalyst exhibit excellent performance in the photocatalytic degradation of organic pollutants. Under visible light irradiation and in the presence of 1 g/L of the catalyst, 10 mg/L of methyl orange (MO) in water could be completely degraded within 20 min, and the degradation rate of tetracycline (TC) reached 99.23% within 5 min. CoAl-LDH/BiO(OH)XI1−X still maintained good photocatalytic degradation activity of tetracycline after five cycles, and the structure of the catalyst did not change. The reaction mechanism related to the degradation of TC by photocatalytic reactions was explored in detail, and the photoexcitation of the semiconductor heterojunction, as well as the subsequent free radical reaction process and the degradation pathway of TC were clarified. This work provides a promising strategy for the preparation of efficient photocatalytic materials and the development of water purification technology. [ABSTRACT FROM AUTHOR]

Organic dye pollutants are the most common type of pollutant found in water and wastewater as a result of various industrial activities. In particular, one of the largest contributors is the textile industry, which uses a lot of organic dyes to produce its goods. Organic dyes that remain in the effluents are typically permanent and difficult to detoxify using traditional wastewater treatment strategies. Photocatalysis using semiconductors have emerged as an attractive wastewater treatment method for resolving the major drawbacks of traditional methods. Montmorillonite has been presented as a conceivable dye adsorbent. When a semiconductor is incorporated, its adsorptive capability assists in imposing heterogeneous photoactivity. It is widely employed in a variety of applications due to fundamental characteristics such as high flexibility, swelling, ion exchange ability, acidity, usage in catalytic amounts, milder reaction conditions, benefit in reusability, selectivity, high yield, cheap cost, and so on. In this review, we specifically describe the last 3 years' development of dye degradation employing recently developed montmorillonite (MMT)‐based materials, as well as their preparation methods. In addition, the photocatalytic degradation of various types of organic dye pollutants, such as anionic and cationic dyes, was also studied in this review. The findings reveal that MMT‐based materials have a wide range of applications in the photocatalytic degradation of contaminants existing in the environment. [ABSTRACT FROM AUTHOR]

Combination of adsorption and photocatalytic degradation is an effective strategy for rapid elimination of organic pollutants from contaminated water. Herein, in order to improve the dispersion of catalyst, increase the reactive sites and facilitate the recovery of catalyst, a magnetic silver phosphate/strontium ferrite/graphene oxide (ASG) ternary composite was constructed through a two-step method. According to PL, UV–vis and photoelectrochemical characterization and adsorption experimental results, the ASG exhibits enhanced light absorption, reduced band gap, increased photocurrent response and improved adsorption ability compared to Ag3PO4 and Ag3PO4/SrFeO. ASG showed remarkable adsorption–photocatalytic synergistic removal effect on levofloxacin (LEO) and methylene blue (MB). At room temperature, for 20 mg/L of initial LEO concentration, 0.67 g/L of ASG can absorb 80.7% of LEO, while the removal rate increases up to 95.5% under visible light irradiation within 180 min; for 20 mg/L of initial MB concentration, 0.67 g/L of ASG can absorb 100% of MB with 90 min, while the elimination time can be shortened to 45 min through adsorption–photocatalytic synergy. The cyclic experiments showed that the removal rates of LEO and MB by ASG remained above 80% after 5 adsorption–photocatalytic cycles, indicating that ASG has good stability and availability. In addition, a possible mechanism for removing LEO and MB by ASG is proposed based on the free radical capture experimental, UV–vis and photoelectrochemical results, which provides references for the rational design and construction of magnetic multifunctional photocatalysts for the efficient removal of organic contaminants in practical wastewater. [ABSTRACT FROM AUTHOR]

Achieving high photoelectrochemical conversion efficiency requires the logical layout of a composite photocatalyst with optimal charge separation and transfer with ideal light harvesting capabilities to enhance the photocatalytic performance and the degradation rate towards organic pollutants. Herein, a novel In2O3/WO3@Ti4N3Tx S-scheme heterojunction was successfully synthesized and confirmed through valence band VB-XPS and Mott Schottky combined analysis. The formed MXene-doped In2O3/WO3@Ti4N3Tx S-scheme significantly enhances the charge flow and spatial separation with an improved oxidation and reduction ability. An in-built interfacial electric field at the WO3–In2O3 boundary enhanced the light-harvesting capacity, whereas Ti4N3Tx MXene offers a unique electron trapping effect which effectively lowers high charge carrier recombination rate-related photocatalytic deficit. It preserves the exceptional redox potency of the photocatalyst by providing a directed acceleration and effective separation of the photogenerated charges. A high carrier density (ND = 7.83 × 1021 cm−3) with a lower negative flat band (VFB = −0.064 V vs. Ag/AgCl) was obtained by Mott–Schottky analysis for 3 wt% In2O3/WO3@Ti4N3Tx, an indicator that a low overpotential is needed to activate photocatalytic reactions. This study, therefore, provides a novel thought for the design and fabrication of an S-scheme heterojunction for photocatalytic reactions for mineralization of organic pollutants in water and clean energy production. [ABSTRACT FROM AUTHOR]

4-nitrophenol (4-NP) is a frequently encountered toxic phenolic organic pollutant in water. It is important to develop a simple method to treat 4-NP. Small and monodispersed gold nanoparticles often have good catalytic performance of 4-NP. Hemoglobin (Hb) is a kind of common and important protein in organisms. Herein, highly biocompatible bovine hemoglobin-stabilized gold nanoparticles (Aun-Hb NPs) were synthesized using hemoglobin as a biological template. Then, the size, zeta potential, and composition of Aun-Hb NPs were investigated by transmission electron microscopy, dynamic light scattering, and X-ray photoelectron spectroscopy. The Aun-Hb NPs with small gold nanoparticles of about 1.4–2.4 nm had good catalytic capabilities in reducing 4-NP to form 4-aminophenol. Au20-Hb NPs demonstrated superior catalytic efficiency in the reduction of 4-NP when compared to other nanoparticles. Moreover, as-synthesized Au20-Hb NPs exhibited excellent biocompatibility through the MTT experiment. The method of preparation of gold nanoparticles offers one way to prepare metal nanoparticles for good potential catalytic applications of gold nanoparticles. [ABSTRACT FROM AUTHOR]

Cyclodextrin–based porous materials have been widely applied in removing various organic pollutants from water environments, due to their unique physical and chemical properties, like the size–matching effect and hydrophobic interaction. Large numbers of hydroxyl groups in its external structure give cyclodextrin a high solubility in water, but the existence of these hydroxyl groups also endows cyclodextrin with the ability to be chemically modified with various functional groups to reduce its solubility in water and, meanwhile, to develop some novel functionalized cyclodextrin–based porous materials for selective removal of the target organic pollutants. This review focuses on the recent development in the synthesis of cyclodextrin–based porous materials (crosslinked cyclodextrin polymers and immobilized cyclodextrins), as well as highlighting their applications and mechanisms in the removal of dyes, endocrine disruptors, and mixed pollutants from water. Finally, the challenges and future perspectives in related research fields are discussed. [ABSTRACT FROM AUTHOR]

Titanium dioxide (TiO2) has been widely studied as a photocatalyst owing to its advantages of low cost, good stability, and nonpollution. However, they can only be excited by ultraviolet light, resulting in low utilization of solar energy and limited photocatalytic efficiency. In recent years, researchers have found that the nonprecious metal Al can effectively improve the photocatalytic performance of TiO2. However, the current studies focus only on enhancing the ultraviolet photocatalysis performance of semiconductors with Al on the substrate. In this study, Al nanoparticles (NPs) and TiO2 were prepared into composite materials. The effects of ligand, Al particle size, and the molar ratio of Al and TiO2 on the photocatalytic degradation of methylene blue (MB) by Al NPs and TiO2 composites (Al NPs/TiO2) were investigated. The results showed that the Al NPs/TiO2 prepared with a particle size of 200 nm of Al, glutathione as the ligand bridge, and an Al:TiO2 ratio of 2:1 were the most effective for the degradation of MB. The degradation rate of 5 mg/L MB solution within 70 min under visible light was up to 99.5%, which was three times higher than that of P25 TiO2. The photocatalytic performance was further enhanced under sunlight with a degradation rate of 99.7% within 50 min, which is four times higher than that of P25 TiO2 under the same light source. Therefore, Al NPs/TiO2 is a potential photocatalytic material for the treatment of organic pollutants in water. [ABSTRACT FROM AUTHOR]

Every year approximately one million tonnes of pesticide effluents are releasing into natural streams and water bodies from nearby industries and agricultural fields. It is necessary to remove pesticides and their residues from water bodies to protect environment and ecosystem. Photodegradation is an effective method to remove the organic contaminants from water bodies due to its low cost, environmental friendliness and absence of secondary pollutants. This work presents about the synthesis, characterization of pure and silver doped ZnO nanoparticles (NPs) and their efficiency towards the photo degradation of carbaryl pesticide. Pure and Ag doped nanoZnO particles were synthesized by wet chemical method using zinc nitrate as precursor and the synthesized nano particles were studied using FT-IR, XRD, UV-Vis, SEM, EDAX, TEM and fluorescence spectral analysis to evaluate its structural, morphological, optical and fluorescent properties. Carbaryl pesticide was taken at a fixed concentration of 5 ppm, and subjected to photo degradation by adding 5 mg/L of pure and Ag doped nanoZnO separately under UV irradiation. It is observed that in 60 min 90 % of the pesticide was degraded with pure ZnO NPs and 98 % with Ag doped ZnO NPs. [ABSTRACT FROM AUTHOR]

The utilization of natural clay minerals for the adsorption of endocrine‐disrupting chemicals (EDCs) presents a cost‐effective and environmentally friendly approach. However, the hydrophilic nature of clay minerals' surface limits their efficacy in removing these hydrophobic pollutants. To overcome these limitations, this study employed two cationic surfactants, cetylpyridinium chloride (CPC) and cetyltrimethylammonium chloride (CTAC), to modify kaolin minerals to enhance their capacity to adsorb a specific type of EDCs, bisphenol A (BPA), and its analogs. The experimental results validated that the surfactant‐modified kaolin exhibited remarkable efficiency in removing BPA from water. The equilibrium adsorption capacities of CPC‐K and CTAC‐K for BPA were determined to be 11.4 mg/g (pH = 2.0–8.0) and 13.4 mg/g (pH = 2.0–6.5), respectively. Kinetic analysis revealed that the BPA adsorption followed a pseudo‐second‐order kinetic process, while isotherm analysis suggested that the BPA adsorption was better described by the Freundlich model (R2 = 0.993–0.998). The surfactant‐modified kaolin demonstrated a retention of over 70% of its initial adsorption capacity after five cycles of desorption and regeneration, further confirming its potential for recycling. Additionally, these modified adsorbents exhibited excellent compatibility in removing bisphenol analogs. These findings provide valuable insights into the practical application of surfactant‐modified clay minerals for the elimination of hydrophobic organic pollutants from water. [ABSTRACT FROM AUTHOR]

Controlling the structure of cerium dioxide (CeO2)-based photocatalysts for the removal of organic contaminants in water is essential. Herein, GO/Fe3O4/CeO2 heterojunction photocatalyst is designed by a clear and simple method for photodegradation of diazinon under visible-light excitation. SEM, EDS, XRD, FTIR, VSM, and UV–vis were used to analyze the crystallinity and morphology of the GO/Fe3O4/CeO2 heterojunction. The UV–Vis analysis revealed a bandgap value of 3.19, 3.08, and 2.98 eV, respectively, for GO, GO@Fe3O4, and GO@Fe3O4@CeO2. The effects of important parameters such as pH (2.0–9.0), photocatalyst dose (10–40 mg), and contact time (0–180 min) were also investigated. The maximum diazinon degradation rate was found to be 97.9% in 60 min. In conclusion, the results indicated that GO@Fe3O4@CeO2 nanocomposite could be used as an efficient photocatalyst for the degradation of organic contaminants from water medium. [ABSTRACT FROM AUTHOR]

Water is the most necessary need for life on the earth. There are a lot of organic pollutants in water. One of the organic pollutants is natural organic substances. Humic acid, a natural organic substance, turns into very harmful substances along with other pollutants. In this study, the humic acid removal from aqueous solution by adsorption using chitosan and chitosan/ZIF 8 composite spheres was examined. Chitosan spheres cross-linked with epichlorohydrin (ECH) and composite spheres consisting of metal organic framework ZIF8 and chitosan were prepared as adsorbents. Equilibrium, kinetic, and thermodynamic studies were investigated for humic acid adsorption by pristine chitosan-ECH and composite chitosan/ZIF 8 adsorbents. Chemical adsorption was found to be compatible with the Freundlich isotherm model and the pseudo-first-order kinetic model for pure chitosan adsorbents. Studies were carried out using chitosan/ZIF8 composite adsorbent, and the most suitable models for chemical adsorption were determined as Langmuir isotherm and pseudo-second order kinetic model. The response surface method was applied with the design expert program to determine the optimum experimental conditions. The adsorption tests were carried out using chitosan-ECH, ZIF 8 and chitosan/ZIF 8 adsorbents for specified optimum conditions, and the humic acid removal was determined as 95.1%, 98.3%, and 97.3%, respectively. In addition, desorption was performed using chitosan-ECH and chitosan/ZIF 8 spheres, and the desorption efficiency was found to be 20.9% and 82.5%, respectively. It has been observed that the developed adsorbents have potential in removing humic acid from water. [ABSTRACT FROM AUTHOR]

Piezocatalysis, a heterogeneous catalytic technique, leverages the periodic electric field changes generated by piezoelectric materials under external forces to drive carriers for the advanced oxidation of organic pollutants. Antibiotics, as emerging trace organic pollutants in water sources, pose a potential threat to animals and drinking water safety. Thus, piezoelectric catalysis can be used to degrade trace organic pollutants in water. In this work, BaTiO3 and La-doped BaTiO3 were synthesized using an improved sol–gel–hydrothermal method and used as piezocatalytic materials to degrade sulfadiazine (SDZ) with ultrasound activation. High-crystallinity products with nano cubic and spherical morphologies were successfully synthesized. An initial concentration of SDZ ranging from 1 to 10 mg/L, a catalysis dosage range from 1 to 2.5 mg/mL, pH, and the background ions in the water were considered as influencing factors and tested. The reaction rate constant was 0.0378 min−1 under the optimum working conditions, and the degradation efficiency achieved was 89.06% in 60 min. La-doped BaTiO3 had a better degradation efficiency, at 14.98% on average, compared to undoped BaTiO3. Further investigations into scavengers revealed a partially piezocatalytic process for the degradation of SDZ. In summary, our work provides an idea for green environmental protection in dealing with new types of environmental pollution. [ABSTRACT FROM AUTHOR]