Free Radical Trapping Research Articles

A novel cobalt-based coordination polymer for rapid degradation of organic dyes in water by visible light assistance

It is crucial to construct an effective photocatalyst for the removal of dyes from aqueous environments. In the present work, a novel cobalt-based coordination polymer was synthesized and characterized with the molecular formula [Co(ipa)(ptt)]n (Co-CP), (ipa = isophthalic acid, ptt = 5-(4-Pyridyl)-1H-tetrazole). In Co-CP, each cobalt ion is in a six-coordination mode and is connected to two adjacent ligands to form a three-dimensional network structure. Furthermore, Co-CP excellent degradation properties and can effectively degrade methylene blue (MB) and rhodamine B (Rh B) under visible light with degradation efficiencies of 84.3 % and 94.6 %, respectively. Additionally, its PXRD patterns and FTIR spectra remained consistent with the original complex after three cycles, which proved that it was very stable, and there was no significant decrease in degradation ability after three cycling cycles, indicating its excellent reusability. The photocatalytic degradation mechanism was subsequently rationalized through free radical trapping experiments and analysis the energy band structure of Co-CP.

Novel Cerium (IV) Oxide -Ti3C2- titanium dioxide heterostructure photocatalyst for pharmaceutical pollutants removal: Photocatalyst characterization, process optimization and transformation pathways

Tetracycline (TC) is a widely applied antibiotic recognized for its potential negative consequences on human health and ecological balance. In this study, a novel photocatalyst, Cerium (IV) oxide -Ti3C2- titanium dioxide (CeMXT), was synthesized through sonochemical and impregnation techniques, subsequently subjected to comprehensive characterization employing diverse methods including XRD, SEM, TEM, HR-TEM, Raman, XPS, and BET. The optimization of TC degradation was pursued using the Response Surface Methodology (RSM), encompassing variables such as initial TC concentration, irradiation duration, photocatalyst dosage, and pH. The degradation efficacy was investigated through free radical trapping experiments, revealing the pivotal roles of OH and superoxide anion radicals. Remarkable degradation efficiency, reaching 94.70 %, was achieved under specific parameter conditions: 22.19 mg/L TC concentration, 104.13 min irradiation, 0.65 g/L photocatalyst dosage, and pH 4.72. This exceptional performance could be attributed to the elevated generation of oxidant species facilitated by the Z-scheme electron transfer heterojunction. Furthermore, LC-Mass analysis was employed to delineate the intermediates formed during TC photodegradation, culminating in proposing a conceivable degradation pathway. The impressive proficiency of the CeMXT photocatalyst underscores its potential application for effective large-scale treatment of persistent organic pollutants in wastewater treatment facilities. Additionally, comparative analysis with a recently developed photocatalyst highlights its promise as a viable alternative for the remediation of such contaminants in aquatic ecosystems.

Magnetically recyclable spherical Cu2O@Fe3O4 S-scheme heterojunction for efficient tetracycline removal via visible light-activated peroxydisulfate.

The overuse of antibiotics in treating bacterial infections is a significant threat to the environment and human health. The utilization of visible-light-assisted peroxydisulfate (PDS) activation for eliminating organic pollutants is a promising approach. This study uses a straightforward hydrothermal method to prepare magnetically recyclable spherical Cu2O@Fe3O4. The efficacy of this material in removing antibiotic pollutants was assessed using simulated wastewater containing tetracycline (TC). TC removal was achieved by activating PDS with Cu2O@Fe3O4 as the visible light photocatalyst. Experimental findings revealed that under specific conditions-a pH of 9, a Cu2O@Fe3O4 concentration of 60 mg L-1, and a PDS concentration of 25 mg L-1-the removal rate of TC reached 97.67% after 30 min of irradiation. Moreover, Cu2O@Fe3O4 exhibited excellent recyclability, maintaining a removal rate of 93.33% after five recycling rounds. X-ray diffraction characterization of the Cu2O@Fe3O4 composite before and after cycling confirmed its robust stability and reusability. In situ X-ray photoelectron spectroscopy analysis showed that electrons migrated from Fe3O4 to Cu2O during the photocatalytic reaction, indicating the formation of an S-type heterojunction in Cu2O@Fe3O4. Free radical trapping experiments demonstrated the active involvement of ·OH, ·O2 -, SO4˙- and h+ radicals in TC removal.

Harnessing potassium peroxymonosulfate activation of WO3/diatomite composites for efficient photocatalytic degradation of tetracycline.

The increasing prevalence of pharmaceutical contaminants in aquatic ecosystems poses profound challenges for both environmental sustainability and public health. Addressing this pressing issue requires the development of innovative, cost-effective, and efficient remediation approaches. Here we report the synthesis of WO3/diatomite composites and their photocatalytic degradation in conjunction with potassium peroxymonosulfate (PMS) activation. By leveraging the synergistic effects, we observe a remarkable degradation of tetracycline, a significant pharmaceutical contaminant, under visible light. Analytically, we have elucidated the driving factors for the enhanced performance, emphasizing the optimal amount of WO3 (10%) in the composite and PMS concentration (3 mM). Specifically, the WO3/diatomite catalyst presents a degradation rate of 80.75% tetracycline (40 mg L-1) after 180 min of visible light irradiation. Also, we elucidate the primary roles of ˙SO4 - radicals in driving the photocatalytic reaction using free radical trapping studies. Our approach not only offers a direct solution to controlling pharmaceutical contamination but also opens new possibilities for advancing the design of composite-based photocatalysts by taking advantage of nature-derived materials.

Efficient removal of tetracycline from MOF-on-MOF heterojunctions driven by visible light: Evaluation of photocatalytic mechanisms and degradation pathway

The low photocatalytic efficiency of a single MOF limits its application, and the assembly of different MOF into MOF-on-MOF heterojunctions can construct fine charge transfer interfaces, thereby improving the photocatalytic ability. In addition, the heterojunction constructed by the two MOFs can maintain the porous structure of the MOF material to a large extent, which is conducive to the adsorption behavior. In this paper, Z-scheme heterojunction is prepared by solvothermal growth of MIL-88B on NH2-MIL-125 matrix. The Z-scheme heterojunction of NH2-MIL-125@MIL-88B greatly improves the photo-response range and charge separation efficiency. It showed good photocatalytic activity for tetracycline (TC) degradation. Under visible light irradiation, the removal efficiency of NM-3 catalyst with the best performance reached 96.26 % within 120 min, and the rate constant was 0.02428 min−1, which was about 9.75 times and 4.16 times of NH2-MIL-125 and MIL-88B alone. The results of free radical trapping and ESR indicated that O2− and OH take important parts in the photodegradation of TC. The active sites and degradation pathways of TC vulnerable to attack were predicted by DFT calculation and intermediate analysis. The design and preparation of Z-scheme heterojunction provide a new strategy for visible light degradation of TC.

A new perspective for surface modifying TiO2 to effectively enhance its visible light photocatalytic activity

In this study, a new perspective was proposed to regulate the photocatalytic properties of TiO2 and a novel TiO2-based composite (BA@TiO2) with nitrogen-containing surface layer was obtained by surface modifying TiO2 with an organic molecular (3,3′-Diaminobenzidine, BA). The composite (BA@TiO2) exhibited high responsiveness to visible light and great photocatalytic activity, which could remove 92% of tetracycline hydrochloride (TC), and also maintained a high ability to photodegrade low concentrations of TC. The free radical trapping experiments showed that h+ and •O2- were the most dominant active species in the degradation process. The possible degradation pathways of TC were deduced with the help of HPLC-MS and fuikui index. QSAR was used to perform toxicity analysis of the degradation intermediates. In addition, the composites demonstrated good recyclable stability and removal efficiency of TC in real water samples, indicating BA@TiO2 is a purifying agent with great efficiency and sustainability for practical treatment of organic pollutants in aqueous media.

Degradation performance study and application of LED light-driven g-C3N4/ZnO composites

In this paper, first-principle calculations based on density-functional theory (DFT) and plane-wave pseudopotential basis for g-C3N4/ZnO composites were carried out using Quantum Espresso (QE) code. The g-C3N4/ZnO composite photocatalytic materials were prepared by solid-phase calcination and characterized by XRD, SEM, and FT-IR. Photocatalytic degradation experiments were carried out under LED light irradiation, using the dye rhodamine B (RhB) and the antibiotic tetracycline hydrochloride (TC) as simulated degradation targets. The degradation performance of the composites was tested using the commercially available pesticide glyphosate. The removal of total nitrogen (TN), total phosphorus (TP), and chemical oxygen demand (COD) from water samples was tested using real sewage livestock wastewater. The photocatalytic degradation mechanism of the composites was explored by free radical trapping experiments. Finally, the MTT cytotoxicity test demonstrated that the g-C3N4/ZnO composite photocatalytic materials are non-cytotoxic and are expected to be used in wastewater treatment.

Theoretical Study on the Multiple Free Radical Scavenging Reactions of Pyranoanthocyanins.

The free radical trapping capacities of multiple pyranoanthocyanins in wine storage and ageing were theoretically explored by density functional theory (DFT) methods. Intramolecular hydrogen bonds were detected in all pyranoanthocyanins, and the planarity of the compounds worsened with an increasing dielectric constant in the environment. Solvents significantly influenced the reaction enthalpies; thus, the preferred thermodynamic mechanisms of the free radical scavenging reactions were modified in different phases. This study incorporates hydrogen atom transfer (HAT), proton loss (PL), electron transfer (ET) reactions, and demethylation (De) of methoxy group mechanisms. The three pyranoanthocyanins have the capacity to capture n1+1 free radicals, where n1 represents the number of methoxy groups. In the gas phase, they prefer employing the n1-De-HAT mechanism on the guaiacyl moiety of the B ring, resulting in the formation of a stable quinone or a quinone radical to scavenge free radicals. In the benzene phase, pyranoanthocyanins trap free radicals via a PL-n1-De-HAT mechanism. In the water phase, the targeted pyranoanthocyanins may dissociate in the form of carboxylate and tend to utilize the n2-PL-n1-De-ET mechanism, where n2 and n1 represent the number of phenolic groups and methoxy groups, respectively, facilitating multiple H+/e- reactions.

3D flower-like Cu-BiOCl/Bi2S3 heterostructure with synergistic Cu ion doping: A study on efficient tetracycline degradation under visible light

In this study, a novel three-dimensional, flower-like Cu-BiOCl/Bi2S3 photocatalyst was synthesized using a two-step calcination and hydrothermal method, aiming at the efficient removal of tetracycline (TC). Through comprehensive characterization techniques, it was discerned that the incorporation of Cu ions extended the light absorption range of BiOCl. Additionally, the formation of a heterojunction significantly enhanced the separation efficiency of space charge. The unique three-dimensional flower-like architecture of the Cu-BiOCl/Bi2S3 photocatalyst augments its surface area exposure and consequently, the density of active sites. This catalyst exhibited a remarkable degradation rate of approximately 95% for TC under visible light irradiation. This performance exhibits a notable enhancement over the degradation rates of BiOCl and Bi2S3, which are approximately 39% and 53% respectively, surpassing them by factors of 2.39 and 1.78. Electron spin resonance (ESR) analysis coupled with free radical trapping experiments pinpointed superoxide radicals (•O2-) and photogenerated holes (h+) as the pivotal active species orchestrating the photocatalytic degradation. Concludingly, a possible TC degradation pathway was proposed based on the intermediates generated during the photocatalytic reaction as detected by Liquid Chromatograph Mass Spectrometer (LC-MS) and Three-Dimension Excitation Emission Matrix (3D EEM).

Synergistic effect of oxygen vacancies and doped sulfur over BiOBr for efficient visible photocatalytic removal of dyes

Herein, the BiOBr co-modified with oxygen vacancies (Vo) and doped by sulfur was a promising photocatalyst (Vo-BiOBr-S), which was synthesized by a one-pot solvothermal approach. The TEM showed that Vo-BiOBr-S is a sea urchin-shaped microsphere with a diameter of about 4 μm. The photocatalytic efficiency of Vo-BiOBr-S was studied by removing rhodamine B and methylene blue, which were higher than that of BiOBr, Vo-BiOBr and BiOBr-0.8S, respectively. Additionally, the photocatalyst exhibits high degradation of aqueous solutions containing both rhodamine B and methylene blue. The photocurrent and photoluminescence tests showed that the improved photocatalytic performance of Vo-BiOBr-S was due to the accelerated charge transfer and separation by the internal electric field, which extended the visible light absorption range. Furthermore, experiments free radical trapping revealed that superoxide radicals were the principal active species in this system, contributing to the superior degradation performance of Vo-BiOBr-S. The density of states of the samples was calculated via DFT to analyse the energy band structure. The effectiveness of Vo-BiOBr-S in mineralising RhB under LED light was demonstrated through total organic carbon tests. This study presents a method to design efficient photocatalysts for use in environmental preservation.

A comparative study of the antioxidant activities of three series of first- and second-generation PPI dendrimers (G1 and G2) functionalized by2- hydroxy-P-naphthoquinone

The work presented focuses on synthesizing molecules capable of blocking the deleterious effects of oxidative stress. Oxidative stress is caused by an imbalance between the pro-oxidant and antioxidant systems, with the former benefiting. It is implicated in numerous pathologies, either as a cause or a consequence. Oxidative stress is involved in chronic processes such as atherosclerosis and diabetes. The work presented in this article focuses firstly on the synthesis of a new class of first- and second-generation PPI dendrimers (G1 and G2) functionalized with 2-hydroxy-p-naphthoquinone, and secondly on the evaluation of their antioxidant activity. The dendrimeric molecules were obtained using an on-pot synthesis based on the Manich reaction. The molecules were characterised using the usual methods: 1H NMR, 13C NMR and dept, infrared (IR) and mass spectrometry. The antioxidant activity of the compounds was assessed by monitoring the scavenging kinetics of the DPPH (1,1-diphenyl-2-picryl-hydrazyl) radical. For the synthesis, three dendrimers, first- and second-generation PPI (G1 and G2) functionalised by 2-hydroxy-p- naphthoquinone, were synthesised (1a, 1b and 2). Concerning the antioxidant tests of the molecules synthesised, it can be seen that all the dendrimers have the ability to trap free radicals and that the values for the percentages of DPPH reduced are very different. A comparison of the percentages of DPPH reduced showed that P1b <P2< P1a. A study of antioxidant activity using the DPPH method revealed that the dendrimers synthesised have antioxidant activity. All the results obtained were interesting.

Boosting oxidative desulfurization from liquid fuels with CuO-MgO assisted by MgMoO4 co-catalyst

Developing a highly efficient catalyst is one of the important topics in the field of oxidative desulfurization from liquid fuels. In this study, the composite metal oxide catalysts (CuO-MgO) with co-catalyst MgMoO4 were prepared by co-precipitation method with simple process, high efficiency and good performance and their structures characterized. An efficient extractive catalytic oxidative desulfurization (ECODS) system for liquid fuel was successfully developed on the basis of as-prepared CuO-MgO-MgMoO4 (CuMgMo) as the catalyst, sodium hypochlorite (NaClO) as the oxidant, and acetonitrile as the extractant. Taking the n-decane and n-tetradecane containing dibenzothiophene (DBT) as the test model oil sample, the main parameters influencing desulfurization performance were examined in detail, such as the molybdenum content, the dosage of CuMgMo, the reaction temperature, the initial S-concentration, the different extractants, the volume ratio of extractant to oil, the different oxidants, and the molar ratio of NaClO to DBT. Based on optimized desulfurization reaction conditions, the model oil containing different sulfur compounds (benzothiophene, 4-methyldibenzothiophene, and 4,6-dimethyldibenzothiophene) and the real oil (straight-run gasoline, straight-run kerosene, and straight-run diesel) were further tested. Based on the free radical trapping experiments and the calculation of density functional theory, the reaction mechanism was deeply explored. The results showed that the de-electron reaction of DBT was mainly catalyzed by MgMoO4 and the reaction of HClO obtaining electron was mainly catalyzed by CuO. MgMoO4 plays an assisting role in improving the catalytic reaction rate. This work will provide a useful reference for the construction of efficient ECODS system using composite metal oxides.

Synthesis of novel Gr/KTaO3 nanocubes by in-situ grown graphene with improved visible light photocatalytic activity

In this work, a novel method was used to prepare KTaO3 using KF and Ta2O5 to prepare KTaO3 nanocubes. Then graphene/ KTaO3 (Gr/KTaO3) composites were synthesized by in-situ growth of graphene on KTaO3 nanocubes for the first time. The prepared KTaO3 possesses a small crystallite size and high crystallinity. The Gr/KTaO3 composites have higher photocatalytic efficiency compared to pure KTaO3. Particularly, Gr/KTaO3 90 had the highest photocatalytic activity, as it was able to degrade 99.5% of rhodamine B (RhB) within 40 min. According to ultraviolet and visible spectrum (UV-Vis) spectra, the absorption sideband of composites redshifts to the visible light area. Based on the results of PL and EIS, the increasing photocatalytic efficiency can be credited to the fact that graphene provides an efficient channel for electron transfer, which promotes photogenerated electron-hole pairs separation. Moreover, a free-radical trapping test indicated that h+ and •OH were the main species in the photodegradation. Our investigation results can serve as a valuable guideline for the development of efficient photocatalysts based on KTaO3 and graphene, which can be used in the removal of organic pollutants during environmental cleanup.

Synthesis of novel ZnIn0.2Ga1.8O4/CaIn2S4 composite material with S-scheme heterojunction for efficient photocatalytic degradation of organic pollutants and hydrogen evolution

Semiconductor photocatalysts that can both photocatalytic evolve hydrogen from water and degrade organic pollutants are very important to solve the problem of energy shortage and environmental pollution. The S-scheme ZnIn0.2Ga1.8O4/CaIn2S4 complex was successfully synthesized using sol–gel and oil bath methods. Characterization technique indicates that chrysanthemum-shaped CaIn2S4 is anchored on the surface of irregular nanoparticles ZnIn0.2Ga1.8O4, forming a closely packed heterostructure. The bandgap values of CaIn2S4 and Zn(In0.1Ga0.9)2O4 were determined as 2.11 eV and 3.61 eV, respectively. Under visible-light irradiation, the ZnIn0.2Ga1.8O4/CaIn2S4-1(ZC-1) photocatalyst exhibited superior performance in degrading an organic pollutant (RhB) and generating hydrogen compared to ZnGa2O4, ZnIn0.2Ga1.8O4, and CaIn2S4 alone. The photocatalytic degradation of RhB using ZC-1 was 1.7, 1.31, and 1.14 times higher than that of ZnGa2O4, ZnIn0.2Ga1.8O4, and CaIn2S4, respectively. Moreover, the photocatalytic hydrogen evolution rate of ZC-1 was 5.8, 3.7, and 13 times higher than that of ZnGa2O4, ZnIn0.2Ga1.8O4, and CaIn2S4, respectively. The formation of S-type heterojunctions in the composite photocatalysts was confirmed through free radical trapping and electron paramagnetic resonance tests, further enhancing hydrogen production and organic pollutant degradation. This study presents a novel approach for developing ZnGa2O4-based composite photocatalysts with S-scheme heterojunctions to address energy shortage and environmental pollution in the future.

Highly dispersed Fe/SnS2/kaolinite composite for the enhanced photo-Fenton degradation of tetracycline hydrochloride

A novel Fe/SnS2/kaolinite (Fe/SK) composite photocatalyst was successfully prepared herein to degrade tetracycline hydrochloride (TCH) in a photo-Fenton system. 5%Fe/SK-20% achieved the best TCH degradation efficiency in the photo-Fenton system within 60 min (80.38%), which was considerably higher than that achieved using pure SnS2 (31.46%). The introduction of the kaolinite carrier increased the dispersion of SnS2 particles and exposed more reactive sites, while Fe doping improved the energy band structure of SnS2 and enhanced electron transfer. Furthermore, photogenerated e− promoted the Fe2+/Fe3+ redox cycle, which facilitated the continuous and efficient activation of H2O2. Liquid chromatography–mass spectrometry was employed to identify the intermediate products and propose the possible pathway for TCH degradation. Free-radical trapping experiment and electron paramagnetic resonance revealed that •OH was the primary active substance in the 5%Fe/SK-20%/visible (vis)/H2O2 system, while h+ and •O2− were the auxiliary substances. In addition to TCH, 5%Fe/SK-20% exhibited excellent degradation efficiency for various organic pollutants, such as oxytetracycline hydrochloride, chlortetracycline hydrochloride, rhodamine B, and methyl orange, in the vis/H2O2 system. This study provides new insights into the efficient decontamination of antibiotic wastewater by kaolinite-based photocatalysts in a photo-Fenton system.

One-pot synthesis of an Au modified BiOCOOH plasmonic photocatalyst with enhanced photocatalytic activity

In this work, we designed the plasmonic photocatalyst of Au–BiOCOOH through a one-pot method, which can be used to effectively treat wastewater contaminated with rhodamine (RhB) and tetracycline (TC). Compared with neat BiOCOOH, as expected, the resulting Au–BiOCOOH illustrated significantly boosted photocatalytic efficiency for degrading RhB and TC under visible light illumination. Remarkably, 3.0%Au–Bi showed the most optimal performance against RhB and TC, achieving degradation rates of 99.5 % and 99.7 % within 120 min. Through multiple characterization techniques, the physical and chemical photoelectric properties of the photocatalyst as well as the photocatalysis mechanism were discussed in detail. UV–visible diffuse reflectance spectroscopy (DRS) analysis demonstrates that the loading of Au nanoparticles (Au NPs) onto 2D nanosheets of BiOCOOH significantly expanded the wavelength range of response of BiOCOOH to visible light. Separately, the outcomes of electrochemical impedance spectroscopy (EIS) and photoluminescence (PL) manifestly reveal that the presence of Au NPs on BiOCOOH can efficiently reduce the interfacial charge transfer resistance and accelerate the photogenerated charge transfer. The free radical trapping test provided evidence for the essential role played by holes (h+) and superoxide radicals (·O2−) were involved in the degradation of RhB. The study provided a possibility to improve the photocatalytic efficiency of BiOCOOH.

Analysis of Photocatalytic Properties of NS-CQDs/g-C3N4 Composites.

N- and S-doped CQDs were prepared using L-cysteine as a precursor. Different NS-CQDs/g-C3N4 composite photocatalysts were formed by modifying graphite-phase carbon nitride with different contents of NS-CQDs using a hydrothermal method. The morphology, constituent elements and functional groups of the composite photocatalysts were analyzed by SEM, EDS, TEM, Mapping, XRD and FT-IR as a proof of its successful preparation. Meanwhile, it was characterized by PL, UV-Vis DRS and electrochemical impedance, which proved that the CQDs could be used as an electronic memory in the composite system to accelerate the electron transfer induced by the photo-excitation of g-C3N4 and effectively inhibit the recombination of e--h+ improvement of the photocatalytic activity of g-C3N4. The stability of the composite photocatalysts under different conditions and the photodegradation activity of Rh B under visible light were investigated. It was found that the photocatalytic degradation efficiency of rhodamine B by NS-CQDS-modified g-C3N4 was significantly higher than that of pure g-C3N4, which could reach 90.82%, and its degradation rate was 3.5 times higher than that of pure g-C3N4. It was demonstrated by free radical trapping experiments that ·OH and ·O2- were the main active species in the photocatalytic degradation process, in which ·O2- played a guiding role.

Self-assembled B-doped flower-like graphitic carbon nitride with high specific surface area for enhanced photocatalytic performance

Graphitic carbon nitride (g-C3N4) is a promising nonmetallic photocatalyst. In this manuscript, B-doped 3D flower-like g-C3N4 mesoporous nanospheres (BMNS) were successfully prepared by self-assembly method. The doping of B element promotes the internal growth of hollow flower-like g-C3N4 without changing the surface roughness structure, resulting in a porous floc structure, which enhances the light absorption and light reflection ability, thereby improving the light utilization rate. In addition, B element provides lower band gap, which stimulates the carrier movement and increases the activity of photogenerated carriers. The photocatalytic mechanism and process of BMNS were investigated in depth by structural characterization and performance testing. BMNS-10 % shows good degradation for four different pollutants, among which the degradation effect on Rhodamine B (RhB) reaches 97 % in 30 min. The apparent rate constant of RhB degradation by BMNS-10 % is 0.125 min−1, which is 46 times faster compared to bulk g-C3N4 (BCN). And the photocatalyst also exhibits excellent H2O2 production rate under visible light. Under λ > 420 nm, the H2O2 yield of BMNS-10 % (779.9 μM) in 1 h is 15.9 times higher than that of BCN (48.98 μM). Finally, the photocatalytic mechanism is proposed from the results of free radical trapping experiments.

Surface modification of bagasse fibers based on polyphenol-induced self-supplied lignin for the creation of composite SBS-modified asphalt

Agroforestry solid waste bagasse fiber (BF) possesses sustainable, carbon-neutral characteristics when used as a reinforcement material for asphalt pavements. However, the incompatibility between BF and the asphalt matrix limits its wide application. This study proposes a strategy for cost-effective and environmentally friendly modification of fiber surfaces, aiming to transform a drawback into an advantage. That is, the lignin in BF, which affects the tensile strength of fibers, is dissolved by a deep eutectic solvent (DES) system, and then the lignin is reborn on the surface of the fibers with the assistance of tannic acid. Based on the hydrophobicity and free radical trapping properties of lignin, regenerated lignin is expected to act as a natural coupling agent between BF and styrene-butadiene-styrene (SBS) asphalt materials and as an anti-aging agent for asphalt. The experimental results showed that the modified BF realized the enhancement of asphalt interfacial compatibility and toughening of asphalt matrix. Specifically, the shear resistance, viscoelasticity and rutting resistance of the modified BF/SBS-modified asphalt were improved by 46.61%, 22.67% and 30.06%, respectively, and the UV aging susceptibility was decreased by 75.02% compared with that of the BF/SBS-modified asphalt. In conclusion, this work introduces a simple and practical strategy for enhancing the interaction between BF and asphalt, which is crucial for advancing biomass recycling and green transportation development.

Electron bridge rGO synergized with Z-scheme ZnTe/WO3 heterojunction for simultaneous and efficient tetracycline degradation and Cu (II) reduction

Z-scheme heterojunction photocatalysts can restrain carriers’ recombination while retaining high redox capacity. Herein, a novel ZnTe/rGO/WO3 (ZRW) Z-scheme heterojunction was constructed for simultaneous removal of TC and Cu (II) from wastewater. The highly conductive rGO served as a bridge connecting the ZnTe and WO3 whereby forming a tight interaction interface, beneficial to carriers transfer and separation. The removals of TC and Cu (II) using the optimized ZRW-10% achieved 90.6% and 89.5% within 150 min of light exposure, which were much higher than those from the ZnTe and WO3. Results of free radical trapping experiments and electron spin resonance analysis suggested that·O2- and·OH were the key active species for TC oxidation while e- dominated Cu (II) reduction. Based on the identified TC degradation intermediates, two possible degradation pathways for TC were proposed, and the ecotoxicity of most intermediates were less than TC. This study can advance research development of designing efficient Z-scheme photocatalyst and elimination of complex pollutants.