0D/3D coupling of g-C3N4 QDs/hierarchical macro-mesoporous CuO-SiO2 for high-efficiency norfloxacin removal in photo-Fenton-like processes

Simultaneous enhanced antibiotic pollutants removal and sustained permeability of the membrane involving CoFe2O4/MoS2 catalyst initiated with simple H2O2 backwashing

Membranes for wastewater treatment should ideally exhibit sustainable high permeate production, enhanced pollutant removal, and intrinsic physical rejection. In this study, CoFe2O4/MoS2 serves as a non-homogeneous phase catalyst; it is combined with polyether sulfone membranes via liquid-induced phase separation to simultaneously sustain membrane permeability and enhance antibiotic pollutant degradation. The prepared catalytic membranes have higher pure water flux (329.34 L m-2 h-1) than pristine polyethersulfone membranes (219.03 L m-2 h-1), as well as higher mean pore size, porosity, and hydrophilicity. Under a moderate transmembrane pressure (0.05 MPa), tetracycline (TC) in synthetic and real wastewater was degraded by the optimal catalytic membrane by 72.7 % and 91.2 %, respectively. Owing to the generation of the reactive oxygen species (ROS) during the Fenton-like reaction process, the catalytic membrane could exclude the natural organics during the H2O2 backwash step and selectively promote fouling degradation in the membrane channel. The irreversible fouling ratio of the catalyzed membrane was significantly reduced, and the flux recovery rate increased by up to 91.6 %. A potential catalytic mechanism and TC degradation pathways were proposed. This study offers valuable insights for designing catalytic membranes with enhanced filtration performance.

Z-scheme heterojunction composed of Fe-doped g-C3N4 and Bi2MoO6 for photo-fenton degradation of antibiotics over a wide pH range: Activity and toxicity assessment

In photo-Fenton technology, the narrower pH range limits its practical application for antibiotic wastewater remediation. Therefore, in this study, a Z-scheme heterojunction photo-Fenton catalyst was constructed by Fe-doped graphite-phase carbon nitride in combination with bismuth molybdate for the degradation of typical antibiotics. Fe doping can shorten the band gap and increase visible-light absorption. Simultaneously, the constructed Z-scheme heterojunction provides a better charge transfer pathway for the photo-Fenton reaction. Within 30 min, Fe3CN/BMO-3 removed 95.54% of tetracycline hydrochloride (TC), and its remarkable performance was the higher Fe3+/Fe2+ conversion efficiency through the decomposition of H2O2. The Fe3CN/BMO-3 catalyst showed remarkable photo-Fenton degradation performance in a wide pH range (3.0-11.0), and it also had good stability in the treatment of TC wastewater. Furthermore, the order of action of the active species was h+ > ·O2- > 1O2 > ·OH, and the toxicity assessment suggested that Fe3CN/BMO-3 was effective in reducing the biotoxicity of TC. The catalyst proved to be an economically feasible and applicable material for antibiotic photo-Fenton degradation, and this study provides another perspective on the application of elemental doping and constructed heterojunction photo-Fenton technology for antibiotic water environmental remediation.

Environmental remediation of the norfloxacin in water by adsorption: Advances, current status and prospects

Antibiotics are considered as the new generation water pollutants as these disturb endocrine systems if water contaminated with antibiotics is consumed. Among many antibiotics norfloxacin is present in various natural water bodies globally. This antibiotic is considered an emerging pollutant due to its low degradation in aquatic animals. Besides, it has many side effects on human vital organs. Therefore, the present article discusses the recent advances in the removal of norfloxacin by adsorption. This article describes the presence of norfloxacin in natural water, consumption, toxicity, various adsorbents for norfloxacin removal, optimization factors for norfloxacin removal, kinetics, thermodynamics, modeling, adsorption mechanism and regeneration of the adsorbents. Adsorption takes place in a monolayer following the Langmuir model. The Pseudo-second order model represents the kinetic data. The adsorption capacity ranged from 0.924 to 1282 mg g-1. In this sense, the parameters such as the NFX concentration added to the adsorbent textural properties exerted a great influence. Besides, the fixed bed-based removal at a large scale is also included. In addition to this, the simulation studies were also discussed to describe the adsorption mechanism. Finally, the research challenges and future perspectives have also been highlighted. This article will be highly useful for academicians, researchers, industry persons, and government authorities for designing future advanced experiments.

Ferrocenylselenoether and its cuprous cluster modified TiO2 as visible-light photocatalyst for the synergistic transformation of N-cyclic organics and Cr(vi)

In this study, fcSe@TiO2 and [Cu2I2(fcSe)2]n@TiO2 nanosystems based on ferrocenylselenoether and its cuprous cluster were developed and characterized by X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HR-TEM), energy dispersive X-ray spectroscopy (EDX), and electron paramagnetic resonance (EPR). Under optimized conditions, 0.2 g L-1 catalyst, 20 mM H2O2, and initial pH 7, good synergistic visible light photocatalytic tetracycline degradation and Cr(vi) reduction were achieved, with 92.1% of tetracycline and 64.5% of Cr(vi) removal efficiency within 30 minutes. Mechanistic studies revealed that the reactive species ˙OH, ˙O2-, and h+ were produced in both systems through the mutual promotion of Fenton reactions and photogenerated charge separation. The [Cu2I2(fcSe)2]n@TiO2 system additionally produced 1O2 from Cu+ and ˙O2-. The advantages of the developed nanosystems include an acidic surface microenvironment provided by Se⋯H+, resourceful product formation, tolerance of complex environments, and excellent adaptability in refractory N-cyclic organics.

Constructing α-Fe2O3/g-C3N4/SiO2 S-scheme-based heterostructure for photo-Fenton like degradation of rhodamine B dye in aqueous solution

This work successfully fabricated graphitic carbon nitride and magnetically recoverable α-Fe2O3/g-C3N4/SiO2 photo-Fenton catalysts using thermal polycondensation and in situ-simple precursor drying-calcination process, respectively, was examined for model synthetic rhodamine B (RhB) dye in the presence of H2O2 and acidic pH under simulated visible light irradiation. An aqueous suspension of the reaction mixture of dye-containing wastewater was fully degraded and reached 97% of photo-Fenton degradation efficiency within 120 min followed by the production of hydroxyl radical (•OH). The dominant hydroxyl radical position generated surface charge, electrostatic potential distribution, and average local ionization potential, which contributed to the complete mineralization of RhB dye, according to the density functional theory (DFT) calculations. HPLC and GCMS experiments were performed to examine the degradation fragments of RhB and draw a plausible mechanistic pathway which showed that RhB degradation generated a series of N-deethylated products, followed by a one-time ring-opening, which indicated that photosensitization induced a photocatalysis reaction mechanism.

Efficient Fenton-like degradation of tetracycline by stalactite-like CuCo-LDO/CN catalysts: The overlooked contribution of dissolved oxygen

In the Fenton-like processes, the resources that exist in the system itself (e.g., dissolved oxygen, electron-rich pollutants) are often overlooked. Herein, a novel CuCo-LDO/CN composite catalyst with a strong "metal-π" effect was fabricated by in situ calcination which could activate dissolved oxygen to generate active oxygen species and degrade the electron-rich pollutants directly. The CuCo-LDO/CN (1:10) with the largest specific surface aera, most C-O-M bonds and least oxygen vacancies exhibited the best catalytic performance for tetracycline (TC)degradation (TC removal efficiency 93.2% and mineralization efficiency 40%, respectively, after 40 min at neutral pH) compared to CuCo-LDO and other CuCo-LDO/CN composite catalysts. In the absence of H2O2, dissolved oxygen could be activated by the catalyst to generate O2·-and ·OH, which contributed to approximately 20.7% of TC degradation, providing a faster and cost-effective way for TC removal from wastewater. While in the presence of H2O2, it was activated by CuCo-LDO/CN to generate·OH as the dominant reactive oxygen species and meanwhile TC transferred electrons to H2O2 through C-O-M bonds, accelerating the Cu+/Cu2+ and Co2+/Co3+ redox cycles. The possible degradation pathways of TC were proposed, and the environmental hazard of TC is greatly mitigated according to toxicity prediction.

Architecting the Z-scheme heterojunction of Gd2O3/g-C3N4 nanocomposites for enhanced visible-light-induced photoactivity towards organic pollutants degradation

A basic calcination process in one step was employed to create g-C3N4 photocatalytic composites modified by Gd2O3 nanoparticles. SEM (scanning electron microscopy), FTIR (Fourier-transform infrared spectroscopy), XRD (X-ray diffraction), EIS (electrochemical impedance spectroscopy), PL (photoluminescence studies) as well as TEM (transmission electron microscopy), XPS (X-ray photoelectron spectroscopy), and CV (cyclic voltammetry) were employed to explain the structural traits, optical properties, and morphological features of the processed photocatalyst. The findings show that Gd2O3 (Gd) does not affect the sample's crystalline structure but rather increases g-C3N4 surface area by spreading it superficially. Furthermore, Gd can redshift the light absorption peak, reduce the energy gap, and improve the efficiency with which photogenerated holes and electrons are removed in g-C3N4. The surface morphology of g-C3N4, in particular, could be significantly enhanced. We similarly employed three distinct photocatalytic complexes of Gd2O3 and g-C3N4 in 1:1, 2:1, and 3:1 proportions to degrade methylene blue (MB). After 100 min in visible light (400-800 nm), the photodegradation rate of composites is 58.8% for 1:1 (GG1), 94.5% for 2:1 (GG2), and 92% for 3:1 (GG3). In addition to the MB dye, the photocatalytic activity of synthesized materials was also studied for methyl orange. The result shows phenomenal degradation values, i.e.; for GG1 86%, GG2 96%, and for GG3 84.6%. The narrow band gap that separates the photogenerated electron and hole enhances g-C3N4 ability to degrade photo-catalytically. From the result, we concluded that the photocurrent and cyclic photocatalytic degradation of methylene blue shows that a composition of 2:1 Gd2O3/g-C3N4 has high photocatalytic stability.

Ciprofloxacin degradation performances and mechanisms by the heterogeneous electro-Fenton with flocculated fermentation biochar

Antibiotic fermentation residue flocculated by polymeric ferric sulfate (PFS) has been classified as a "hazardous waste" in China. In this study, it was recycled into antibiotic fermentation residue biochar (AFRB) by pyrolysis and used as a heterogeneous electro-Fenton (EF) catalyst for ciprofloxacin (CIP) degradation. The results show that PFS was reduced to Fe⁰ and FeS during pyrolysis, which was beneficial for the EF process. The AFRB with mesoporous structures exhibited soft magnetic features, which were convenient for separation. CIP was completely degraded within 10 min by the AFRB-EF process at an initial concentration of 20 mg/L. Increasing the working current and catalyst dosage within a certain range could improve the degradation rate. ·OH and O₂^·- were the dominant reactive oxygen species that played critical roles for CIP degradation. The antibacterial groups of CIP have been destroyed by the heterogeneous electro-Fenton process and its toxicity was negligible. The AFRB showed satisfactory performance, even though it was recycled five times. This study provide new insights into the resourceful treatment of antibiotic fermentation residues.

An optimization strategy for photo-Fenton-like catalysts: Based on crystal plane engineering of BiVO4 and electron transfer properties of 0D CQDs

Herein, we report a novel Cu₂(OH)₃ F/CQDs-BiVO₄ composite photo-Fenton-like system, which used BiVO₄ and Cu₂(OH)₃F as electron donor and acceptor, respectively, and achieved efficient electron transfer between them through the electron bridging effect of Carbon quantum dots (CQDs). The material exhibited excellent ciprofloxacin (CIP) removal efficiency in the photo-Fenton-like coupled system. Cu₂(OH)₃ F/CQDs-BiVO₄ had an incredibly fast response rate, eliminating 98.1% of CIP from the solution in just 1 h, according to the reaction kinetics. Exploratory tests proved that the catalyst kept up a sufficient level of activity across a wide pH range of 3-11 and in the presence of various anions. The activity, morphology, and crystal structure of the samples did not appreciably alter after five recycles. Finally, a possible reaction mechanism was also proposed based on the band structure, position and reaction species.

0D carbon dots intercalated Z-scheme CuO/g-C3N4 heterojunction with dual charge transfer pathways for synergetic visible-light-driven photo-Fenton-like catalysis

Photo-Fenton-like catalysis allows development of novel advanced oxidation technology with promising application in wastewater treatment. In this work, carbon dots (CDs) were intercalated between CuO nanoparticles and coralloid flower-like graphitic carbon nitride (g-C₃N₄) to fabricate a ternary CuO/CDs/g-C₃N₄ hybrid for synergetic visible-light-driven photo-Fenton-like oxidation. The CuO/CDs/g-C₃N₄ hybrid showed remarkable degradation efficiency towards recalcitrant organic contamination, excellent tolerance to realistic environmental conditions, exceptional stability and wide universality, declaring great potential for practical applications. •OH and •O₂^- radicals were demonstrated to be the primary contributors in the photo-Fenton-like system. Mechanism studies reveal dual charge transfer pathways in the Z-scheme CuO/g-C₃N₄ heterojunction assisted by interfacial electron transmission bridges of CDs, which can simultaneously boost the reduction of Cu²⁺ to Cu⁺ in the Fenton-like cycle and accelerate the Z-scheme electron flow from CuO to g-C₃N₄, leading to synergistic enhancement of the catalytic performance. This work would afford a feasible strategy to develop reinforced solar energy-assisted photo-Fenton-like catalysis systems for water remediation.

Efficient electron transfer and copper species transformation under the synergy of BiVO4 and novel Cu2(OH)3F nanosheets

Here, we report a simple and efficient strategy for evenly in situ growth of Cu₂(OH)₃F nanosheets on BiVO₄ spheres as a novel photo-Fenton-like catalyst using hydrothermal method. The Cu₂(OH)₃F/BiVO₄ composite catalysts showed great performance for the organic pollutants degradation under visible light irradiation due to the efficient electron transfer and copper species transformation. The synergetic between Cu₂(OH)₃F and BiVO₄ not only promoted the separation of electrons and holes but also enhanced the Cu²⁺ reduction, thus produced more strong oxidative radicals under a wide pH value range. The activity of Cu₂(OH)₃F/BiVO₄ composite for methylene blue degradation was 6.03 and 5.47 times more than that of pristine Cu₂(OH)₃F and BiVO₄, respectively. The composite catalysts were characterized with various methods and their stability and adaptability were also evaluated. Finally, a possible photo-Fenton-like reaction mechanism was also proposed based on the band structure/position and reaction species.

Ceftriaxone sodium degradation by carbon quantum dots (CQDs)-decorated C-doped α-Bi2O3 nanorods

A novel carbon quantum dots decorated C-doped α-Bi₂O₃ photocatalyst (CBO/CQDs) was synthesized by solvothermal method. The synergistic effect of adsorption and photocatalysis highly improved contaminants removal efficiencies. The ceftriaxone sodium degradation rate constant (k) of CBO/CQDs was 11.4 and 3.2 times that of pure α-Bi₂O₃ and C-doped α-Bi₂O₃, respectively. The interstitial carbon doping generated localized states above the valence band, which enhanced the utilization of visible light and facilitated the separation of photogenerated electrons and holes; the loading of CQDs improved the charge carrier separation and extended the visible light response; the reduced particle size of CBO/CQDs accelerated the migration of photogenerated carriers. The •O₂ ^- and h⁺ were identified as the dominant reactive species in ceftriaxone sodium degradation, and the key role of •O₂ ^- was further investigated by NBT transformation experiments. The Fukui index was applied to ascertain the molecular bonds of ceftriaxone sodium susceptible to radical attack, and intermediates analysis was conducted to explore the possible degradation pathways. The toxicity evaluation revealed that some degradation intermediates possessed high toxicity, thus the contaminants require sufficient mineralization to ensure safe discharge. The present study makes new insights into synchronous carbon dopping and CQDs decoration on modification of α-Bi₂O₃, which provides references for future studies.

A review of the adsorption method for norfloxacin reduction from aqueous media

Norfloxacin (NRFX) is one of a class of antibiotics known as broad-spectrum fluoroquinolone antibiotic that is frequently used to treat infectious disorders in both animals and humans. NRFX is considered an emergent pharmaceutical contaminate. This review's objective is to evaluate empirical data on NRFX's removal from aqueous medium. The environmental danger of NRFX in the aquatic environment was validated by an initial ecotoxicological study. Graphene oxide/Metal Organic Framework (MOF) based composite, followed by Magnesium oxide/Chitosan/Graphene oxide composite gave the highest NRFX adsorption capacities (Qmax) of 1114.8 and 1000 mg/g, respectively. The main adsorption mechanisms for NRFX uptake include electrostatic interactions, H-bonds, π-π interactions, electron donor-acceptor interactions, hydrophobic interactions, and pore diffusion. The adsorptive uptake of NRFX were most suitably described by Langmuir isotherm and pseudo-second order implying adsorbate-to-adsorbent electron transfer on a monolayer surface. The thermodynamics of NRFX uptake is heavily dependent on the makeup of the adsorbent, and the selection of the eluent for desorption from the solid phase is equally important. There were detected knowledge gaps in column studies and adsorbent disposal method. There's great interest in scale-up and industrial applications of research results that will aid in management of water resources for sustainability.

Electrochemical degradation of antibiotic enoxacin using a novel PbO2 electrode with a graphene nanoplatelets inter-layer: Characteristics, efficiency and mechanism

A novel PbO₂ electrode was fabricated by adding graphene nanoplatelets (GNP) inter-layer into β-PbO₂ active layer (called GNP-PbO₂) and utilized to degradation of antibiotic enoxacin (ENO). The GNP-PbO₂ electrode had a much rougher surface than the typical PbO₂ electrode, with smaller crystal size and lower charge-transfer resistance at the electrode/electrolyte interface. Notably, the GNP inter-layer increased the oxygen evolution potential of PbO₂ electrode (2.05 V vs. SCE), which was very beneficial to inhibit oxygen evolution and promote ·OH production. The relatively best operating parameters for ENO removal and energy efficiency were current density of 20 mA cm^-2, initial pH of 7, initial ENO concentration of 100 mg L^-1 and electrode distance of 4 cm. Furthermore, indirect radical oxidation was found to be the main way during electrolysis process. Based on the observed analysis of intermediate products, the main reaction pathways of ENO included hydroxylation, defluorination and piperazine ring-opening. Finally, combinating with the electro-oxidation capability, stability and safety evaluation, we can conclude that GNP-PbO₂ is a promising anode for treatment of various organic pollutants in wastewater.

Combined BRCA2 and MAGEC3 Expression Predict Outcome in Advanced Ovarian Cancers

Like BRCA2, MAGEC3 is an ovarian cancer predisposition gene that has been shown to have prognostic significance in ovarian cancer patients. Despite the clinical significance of each gene, no studies have been conducted to assess the clinical significance of their combined expression. We therefore sought to determine the relationship between MAGEC3 and BRCA2 expression in ovarian cancer and their association with patient characteristics and outcomes. Immunohistochemical staining was quantitated on tumor microarrays of human tumor samples obtained from 357 patients with epithelial ovarian cancer to ascertain BRCA2 expression levels. In conjunction with our previously published MAGEC3 expression data, we observed a weak inverse correlation of MAGEC3 with BRCA2 expression (r = −0.15; p < 0.05) in cases with full-length BRCA2. Patients with optimal cytoreduction, loss of MAGEC3, and detectable BRCA2 expression had better overall (median OS: 127.9 vs. 65.3 months, p = 0.035) and progression-free (median PFS: 85.3 vs. 18.8 months, p = 0.002) survival compared to patients that were BRCA2 expressors with MAGEC3 normal levels. Our results suggest that combined expression of MAGEC3 and BRCA2 serves as a better predictor of prognosis than each marker alone.

A simple and green method to prepare non-typical yolk/shell nanoreactor with dual-shells and multiple-cores: Enhanced catalytic activity and stability in Fenton-like reaction

Nowadays, non-typical yolk/shell structure has drawn much attentions due to the better catalytic performance than traditional counterparts (one yolk/one shell). In this study, ZIF-67 @Co₂SiO₄/SiO₂ yolk/shell structure was prepared in one-step at room temperature, in which ZIF-67 was served as the hard-template, H₂O was served as etchant and tetraethyl orthosilicat was served as the raw material for Co₂SiO₄/SiO₂. After calcination, the non-typical Co_xO_y @Co₂SiO₄/SiO₂ yolk/shell nanoreactor with Co₂SiO₄/SiO₂ dual-shells and Co_xO_y multiple-cores was obtained. On the one hand, more active sites were exposed on multiple-cores surface and better protection were provided by dual-shells. On the other hand, the sheet-like Co₂SiO₄ inner shell not only extended the travel path and retention time of pollutants trapped in cavity, but also separated the multiple-cores from aggregation. Therefore, the nanoreactor displayed the outstanding catalytic activity and recyclability in Fenton-like reaction. Metronidazole (20 mg/L) was completely degraded after 30 min, rhodamine B (50 mg/L) and methyl orange (20 mg/L) were removed even within 5.0 min. Catalytic mechanism indicated that ¹O₂ greatly contributed to the pollutant degradation. This paper presented a simple, versatile, green and energy-saving method for non-typical yolk/shell nanoreactor, and it could inspire to prepare other catalysts with high activity and stability for environmental remediation.

Analysis of the degradation of m-cresol with Fe/AC in catalytic wet peroxide oxidation enhanced by swirl flow

Catalytic wet peroxide oxidation (CWPO) enhanced by swirl flow (SF-CWPO) was developed for the first time to explore the degradation of m-cresol in 3%iron/activated carbon catalysed Fenton reaction. Under the conditions of catalyst dosage of 0.6 g/L, H₂O₂ dosage of 1.5 mL/L, pH = 6 and reaction time of 20 min, the degradation rate of m-cresol and total organic carbon in 100 mg/L m-cresol solution reaches 81.5% and 82%, respectively. The reaction speed in the SF-CWPO system with an independently designed cyclone reactor was two times faster than the traditional CWPO systems. In addition, via liquid chromatography-mass spectrometry analysis of the degradation product, the possible degradation pathway for m-cresol was proposed. The proposed SF-CWPO can potentially be an efficient and economical method to treat organic pollutants in wastewaters.

Room Temperature Engineering Crystal Facet of Cu2O for Photocatalytic Degradation of Methyl Orange

Cuprous oxide (Cu₂O) has received enormous interest for photocatalysis owing to its narrow band gap of 2.17 eV, which is beneficial for visible-light absorption. In this work, we succeeded in synthesizing Cu₂O nanocrystals with two morphologies, cube and sphere, at room temperature via a simple wet-chemistry strategy. The morphologies of Cu₂O change from cube to sphere when adding PVP from 0 g to 4 g and the mainly exposed crystal faces of cubic and spherical Cu₂O are (100) and (111), respectively. The photocatalytic properties of the as-prepared Cu₂O were evaluated by the photocatalytic degradation of methyl orange (MO). Cubic Cu₂O(100) showed excellent photocatalytic activity. After the optical and photoelectric properties were investigated, we found that cubic Cu₂O(100) has better photoelectric separation efficiency than spherical Cu₂O(111). Finally, the possible mechanism was proposed for cubic Cu₂O(100) degrading MO under visible light.

Efficient removal of antibiotic-resistant bacteria and intracellular antibiotic resistance genes by heterogeneous activation of peroxymonosulfate on hierarchical macro-mesoporous Co3O4-SiO2 with enhanced photogenerated charges

Antibiotic resistance genes (ARGs) and their host antibiotic-resistant bacteria (ARB) are widely detected in the environment and pose a threat to human health. Traditional disinfection in water treatment plants cannot effectively remove ARGs and ARB. This study explored the potential of a heterogeneous photo-Fenton-like process utilizing a hierarchical macro-mesoporous Co₃O₄-SiO₂ (MM CS) catalyst for activation of peroxymonosulfate (PMS) to inactivate ARB and degrade the intracellular ARGs. A typical gram-negative antibiotic-resistant bacteria called Pseudomonas sp. HLS-6 was used as a model ARB. A completed inactivation of ARB at ∼10⁷ CFU/mL was achieved in 30 s, and an efficient removal rate of more than 4.0 log for specific ARGs (sul1 and intI1) was achieved within 60 min by the MM CS-based heterogeneous photo-Fenton-like process under visible light and neutral pH conditions. Mechanism investigation revealed that •O₂^- and ¹O₂ were the vital reactive species for ARB inactivation and ARG degradation. The formation and transformation of the active species were proposed. Furthermore, the hierarchical macro-mesoporous structure of MM CS provided excellent optical and photoelectrochemical properties that promoted the cycle of Co³⁺/Co²⁺ and the effective utilization of PMS. This process was validated to be effective in various water matrices, including deionized water, underground water, source water, and secondary effluent wastewater. Collectively, this work demonstrated that the MM CS-based heterogeneous photo-Fenton-like process is a promising technology for controlling the spread of antibiotic resistance in aquatic environments.

Photo-Fenton-like degradation of antibiotics by inverse opal WO3 co-catalytic Fe2+/PMS, Fe2+/H2O2 and Fe2+/PDS processes: A comparative study

Advanced oxidation processes (AOPs) such as Fenton and Fenton-like process for pollutant removal have been widely reported. However, most papers choose one of the popular oxidants (H₂O₂, peroxymonosulfate (PMS) or peroxydisulfate (PDS)) as the oxidant via AOPs for pollutant degradation. The purpose of this work is to compare the degradation rates of the Fe²⁺/PMS, Fe²⁺/H₂O₂ and Fe²⁺/PDS processes. Furthermore, to solve the problem of slow regeneration of Fe²⁺, the visible light irradiation and inverse opal WO₃ cocatalyst were added to the Fenton/Fenton-like process. The IO WO₃ co-catalytic visible light assisted Fe²⁺/PMS, Fe²⁺/H₂O₂ and Fe²⁺/PDS processes greatly improved the degradation efficiency of norfloxacin (NOR), reaching about 30 times, 9 times and 12 times that of the homogeneous Fenton/Fenton-like process, respectively. On average, the TOC removal rates of PMS-based, H₂O₂-based and PMS-based processes for the five pollutants were 71.6%, 54.0%, and 59.6% within 60 min, and the corresponding co-catalyst treatment efficiencies were 0.215 mmol/g/h, 0.162 mmol/g/h, and 0.179 mmol/g/h, respectively. ¹O₂ and •O₂^- have been proven to play a vital role in the degradation of NOR via all the three IO WO₃ co-catalytic photo-Fenton-like processes. In addition, the effects of different reaction parameters on the activity of degrading norfloxacin were explored. The IO WO₃ co-catalytic visible light assisted Fe²⁺/PMS, Fe²⁺/H₂O₂ and Fe²⁺/PDS processes for removal of different persistent organic pollutants and norfloxacin in different actual wastewater have also been studied. Nonetheless, this study proves that IO WO₃ co-catalytic visible light assisted Fe²⁺/PMS, Fe²⁺/H₂O₂ and Fe²⁺/PDS processes could effectively remove antibiotics from wastewater.

Construction of a hierarchical ZnIn2S4/C3N4 heterojunction for the enhanced photocatalytic degradation of tetracycline

Efficient charge separation and sufficiently exposed active sites are both critical limiting factors for solar-driven organic contaminant degradation. Herein, we describe a hierarchical heterojunction photocatalyst fabricated by the in situ growth of ZnIn₂S₄ nanosheets on micro-tubular C₃N₄ (denoted as ZIS/TCN). This ZIS/TCN heterojunction photocatalyst can take advantage of the hollow structure with stronger light absorption capacity and more active sites, and its heterostructure can accelerate the separation and transfer of photogenerated charge carriers. The optimized ZIS/TCN-3 exhibits superb photocatalytic efficiency for the degradation of tetracycline (86.1%, 60 min), maintains excellent stability and recyclability, and provides a facile strategy for the synthesis of efficient heterojuction photocatalysts towards wastewater treatment. In addition, the plausible photocatalytic degradation pathway of tetracycline is proposed according to the intermediates identified by LC-mass analysis.