The excessive use of pesticides has exacerbated environmental pollution due to herbicide residues,while their persistent toxicity poses serious challenges to global ecological security.A magnetically recyclable CoFe_(...The excessive use of pesticides has exacerbated environmental pollution due to herbicide residues,while their persistent toxicity poses serious challenges to global ecological security.A magnetically recyclable CoFe_(2)O_(4)/BiOBr S-scheme heterojunctions was prepared by microwave-assisted co-precipitation method for photocatalytic degradation of Diuron(DUR) in water.The formation of S-scheme heterojunction enhances electron transfer and charge separation,which was demonstrated by free radical trapping,electrochemical experiments,and DFT calculations.The magnetic CoFe_(2)O_(4)/BiOBr catalysts can achieve 99.9 %removal of diuron in 50 min under visible light irradiation.Furthermore,the system maintains stable performance across a broad p H range(3-9),enabling adaptation to diverse water environments,effective elimination of multiple pollutants,and strong resistance to ionic interference.Using magnetic recovery,CoFe_(2)O_(4)/BiOBr exhibits a high removal rate of 99 % and a markedly low ion leaching rate(<20 μg/L) after six cycles photocatalytic process,confirming its excellent stability and durability.According to HPLCQTOF-MS and DFT calculation,the main ways of DUR degradation include dechlorinated hydroxylation,dealkylation and hydroxylation of aromatic ring and side chain.Toxicity analysis showed that the toxicity of the intermediates generated during degradation was generally lower than that of DUR.The magnetic CoFe_(2)O_(4)/BiOBr S-scheme heterojunction developed in this study exhibits excellent photocatalytic performance,high applicability,good stability,and durability,providing an effective magnetic for the removal of refractory pollutants.展开更多
In this investigation,the structural and electrical properties of nanocomposites of polyaniline(PANI) and cobalt ferrite synthesized by hydrothermal route are reported for the first time(with weight ratios of CoFe_2O_...In this investigation,the structural and electrical properties of nanocomposites of polyaniline(PANI) and cobalt ferrite synthesized by hydrothermal route are reported for the first time(with weight ratios of CoFe_2O_4/PANI 1:2 and 2:1).Synthesized nanomaterials have been characterized by XRD,FT-IR,SEM and TEM techniques.FT-IR results confirm the presence of CoFe_2O_4 and PANI in the samples.Their detailed conductivity measurements have been investigated.It has been found that PANI has a more effective conducting mechanism in CoFe_2O_4-PANI composites.These results are also consistent with the change in AC conductivity orders in composites.展开更多
Electromagnetic interference,which necessitates the rapid advancement of substances with exceptional capabilities for bsorbing electromagnetic waves,is of urgent concern in contemporary society.In this work,CoFe_(2)O_...Electromagnetic interference,which necessitates the rapid advancement of substances with exceptional capabilities for bsorbing electromagnetic waves,is of urgent concern in contemporary society.In this work,CoFe_(2)O_(4)/residual carbon from coal gasification fine slag(CFO/RC)composites were created using a novel hydrothermal method.Various mechanisms for microwave absorption,including conductive loss,natural resonance,interfacial dipole polarization,and magnetic flux loss,are involved in these composites.Consequently,compared with pure residual carbon materials,this composite offers superior capabilities in microwave absorption.At 7.76GHz,the CFO/RC-2 composite achieves an impressive minimum reflection loss(RL_(min))of-43.99 dB with a thickness of 2.44 mm.Moreover,CFO/RC-3 demonstrates an effective absorption bandwidth(EAB)of up to 4.16 GHz,accompanied by a thickness of 1.18mm.This study revealed the remarkable capability of the composite to diminish electromagnetic waves,providing a new generation method for microwave absorbing materials of superior quality.展开更多
Owing to outstanding hydrophilicity and ionic interaction,layered double hydroxides(LDHs)have emerged as a promising carrier for high performance catalysts.However,the synthesis of new specialized catalytic LDHs for d...Owing to outstanding hydrophilicity and ionic interaction,layered double hydroxides(LDHs)have emerged as a promising carrier for high performance catalysts.However,the synthesis of new specialized catalytic LDHs for degradation of antibiotics still faces some challenges.In this study,a CoFe_(2)O_(4)/MgAl-LDH composite catalyst was synthesized using a hydrothermal coprecipitation method.Comprehensive characterization reveals that the surface of MgAl-LDH is covered with nanometer CoFe_(2)O_(4) particles.The specific surface area of CoFe_(2)O_(4)/MgAl-LDH is 82.84 m^(2)·g^(-)1,which is 2.34 times that of CoFe_(2)O_(4).CoFe_(2)O_(4)/MgAl-LDH has a saturation magnetic strength of 22.24 A·m^(2)·kg^(-1) facilitating efficient solid-liquid separation.The composite catalyst was employed to activate peroxymonosulfate(PMS)for the efficient degradation of tetracycline hydrochloride(TCH).It is found that the catalytic performance of CoFe_(2)O_(4)/MgAl-LDH significantly exceeds that of CoFe_(2)O_(4).The maximum TCH removal reaches 98.2%under the optimal conditions([TCH]=25 mg/L,[PMS]=1.5 mmol/L,CoFe_(2)O_(4)/MgAl-LDH=0.20 g/L,pH 7,and T=25℃).Coexisting ions in the solution,such as SO_(4)^(2-),Cl-,H_(2)PO_(4)^(-),and CO_(3)^(2-),have a negligible effect on catalytic performance.Cyclic tests demonstrate that the catalytic performance of CoFe_(2)O_(4)/MgAl-LDH remains 67.2%after five cycles.Mechanism investigations suggest that O_(2)^(•-)and ^(1)O_(2) produced by CoFe_(2)O_(4)/MgAl-LDH play a critical role in the catalytic degradation.展开更多
This study investigates the effect of apple extract on CoFe_(2)O_(4) nanoparticles synthesized via a green self-ignition method.High resolution transmission electron microscope(HRTEM)showed nanometric particles with v...This study investigates the effect of apple extract on CoFe_(2)O_(4) nanoparticles synthesized via a green self-ignition method.High resolution transmission electron microscope(HRTEM)showed nanometric particles with varied shapes,while X-ray diffraction(XRD)and Rietveld refinement confirmed a facecentered cubic(Fd3m)structure.Mössbauer spectroscopy revealed a Zeeman sextet pattern with only Fe^(3+) ions.Ultra violet vissible nearinfrared(UV-Vis-NIR)spectra indicated strong absorbance in the visible and NIR regions,suggesting optoelectronic potential.The nanoparticles demonstrated high photo-Fenton catalytic efficiency,degrading 96.88%of Methylene Blue under visible light.They also exhibited 100%adsorption capacities for Cr^(3+) and Pb^(2+),making them effective for water treatment.These properties were attributed to a large surface area(347.04 m2/g),mesoporous structure,and mixed spinel phase.ANOVA and Tukey’s honestly significant difference(HSD)tests confirmed that contact time and adsorbent dosage significantly affected pollutant removal.Additionally,strong antimicrobial activity highlighted their biotechnological relevance.The inclusion of apple extract enhanced structural and functional features,expanding application prospects in spin valves,magnetic recording,refrigeration,microwave technologies(C to Ku bands),optoelectronics,and biotechnology.Future work should explore the photo-Fenton degradation mechanism and optimize synthesis for scalable production,aiming to maximize their industrial utility.展开更多
Supported metal catalysts are the backbone of heterogeneous catalysis,playing a crucial role in the modern chemical industry.Metal-support interactions(MSIs)are known important in determining the catalytic performance...Supported metal catalysts are the backbone of heterogeneous catalysis,playing a crucial role in the modern chemical industry.Metal-support interactions(MSIs)are known important in determining the catalytic performance of supported metal catalysts.This is particularly true for single-atom catalysts(SACs)and pseudo-single-atom catalysts(pseudo-SACs),where all metal atoms are dispersed on,and interact directly with the support.Consequently,the MSI of SACs and pseudo-SACs are theoretically more sensitive to modulation compared to that of traditional nanoparticle catalysts.In this work,we experimentally demonstrated this hypothesis by an observed size-dependent MSI modulation.We fabricated CoFe_(2)O_(4) supported Pt pseudo-SACs and nanoparticle catalysts,followed by a straightforward water treatment process.It was found that the covalent strong metal-support interaction(CMSI)in pseudo-SACs can be weakened,leading to a significant activity improvement in methane combustion reaction.This finding aligns with our recent observation of CoFe_(2)O_(4) supported Pt SACs.By contrast,the MSI in Pt nanoparticle catalyst was barely affected by the water treatment,giving rise to almost unchanged catalytic performance.This work highlights the critical role of metal size in determining the MSI modulation,offering a novel strategy for tuning the catalytic performance of SACs and pseudo-SACs by fine-tuning their MSIs.展开更多
基金supported by the National Natural Science Foundation of China (No.52370174)the Natural Science Foundation of Shandong Province,China (No.ZR2022ME128)Special Projects in Key Areas of Colleges and Universities in Guangdong Province (No.2023ZDZX4050)。
文摘The excessive use of pesticides has exacerbated environmental pollution due to herbicide residues,while their persistent toxicity poses serious challenges to global ecological security.A magnetically recyclable CoFe_(2)O_(4)/BiOBr S-scheme heterojunctions was prepared by microwave-assisted co-precipitation method for photocatalytic degradation of Diuron(DUR) in water.The formation of S-scheme heterojunction enhances electron transfer and charge separation,which was demonstrated by free radical trapping,electrochemical experiments,and DFT calculations.The magnetic CoFe_(2)O_(4)/BiOBr catalysts can achieve 99.9 %removal of diuron in 50 min under visible light irradiation.Furthermore,the system maintains stable performance across a broad p H range(3-9),enabling adaptation to diverse water environments,effective elimination of multiple pollutants,and strong resistance to ionic interference.Using magnetic recovery,CoFe_(2)O_(4)/BiOBr exhibits a high removal rate of 99 % and a markedly low ion leaching rate(<20 μg/L) after six cycles photocatalytic process,confirming its excellent stability and durability.According to HPLCQTOF-MS and DFT calculation,the main ways of DUR degradation include dechlorinated hydroxylation,dealkylation and hydroxylation of aromatic ring and side chain.Toxicity analysis showed that the toxicity of the intermediates generated during degradation was generally lower than that of DUR.The magnetic CoFe_(2)O_(4)/BiOBr S-scheme heterojunction developed in this study exhibits excellent photocatalytic performance,high applicability,good stability,and durability,providing an effective magnetic for the removal of refractory pollutants.
基金the Fatih University,Research Project Foundation (Contract No.P50020902-2)TUBITAK (Contract No.110T487) for financial support of this study
文摘In this investigation,the structural and electrical properties of nanocomposites of polyaniline(PANI) and cobalt ferrite synthesized by hydrothermal route are reported for the first time(with weight ratios of CoFe_2O_4/PANI 1:2 and 2:1).Synthesized nanomaterials have been characterized by XRD,FT-IR,SEM and TEM techniques.FT-IR results confirm the presence of CoFe_2O_4 and PANI in the samples.Their detailed conductivity measurements have been investigated.It has been found that PANI has a more effective conducting mechanism in CoFe_2O_4-PANI composites.These results are also consistent with the change in AC conductivity orders in composites.
基金financially supported by the Key Project of Natural Science Research in Colleges and Universities of Anhui Province,China(No.2022AH050816)the Open Research Grant of Joint National-Local Engineering Research Centre for Safe and Precise Coal Mining(Nos.EC2023013 and EC2022018)+1 种基金the National Natural Science Foundation of China(No.52200139)the Introduction of Talent in Anhui University of Science and Technology,China(Nos.2021yjrc18 and 2023yjrc79)。
文摘Electromagnetic interference,which necessitates the rapid advancement of substances with exceptional capabilities for bsorbing electromagnetic waves,is of urgent concern in contemporary society.In this work,CoFe_(2)O_(4)/residual carbon from coal gasification fine slag(CFO/RC)composites were created using a novel hydrothermal method.Various mechanisms for microwave absorption,including conductive loss,natural resonance,interfacial dipole polarization,and magnetic flux loss,are involved in these composites.Consequently,compared with pure residual carbon materials,this composite offers superior capabilities in microwave absorption.At 7.76GHz,the CFO/RC-2 composite achieves an impressive minimum reflection loss(RL_(min))of-43.99 dB with a thickness of 2.44 mm.Moreover,CFO/RC-3 demonstrates an effective absorption bandwidth(EAB)of up to 4.16 GHz,accompanied by a thickness of 1.18mm.This study revealed the remarkable capability of the composite to diminish electromagnetic waves,providing a new generation method for microwave absorbing materials of superior quality.
基金University Synergy Innovation Program of Anhui Province(GXXT-2022-083)Science and Technology Plan Project of Wuhu City,China(2023kx12)Anhui Provincial Department of Education New Era Education Project(2023xscx070)。
文摘Owing to outstanding hydrophilicity and ionic interaction,layered double hydroxides(LDHs)have emerged as a promising carrier for high performance catalysts.However,the synthesis of new specialized catalytic LDHs for degradation of antibiotics still faces some challenges.In this study,a CoFe_(2)O_(4)/MgAl-LDH composite catalyst was synthesized using a hydrothermal coprecipitation method.Comprehensive characterization reveals that the surface of MgAl-LDH is covered with nanometer CoFe_(2)O_(4) particles.The specific surface area of CoFe_(2)O_(4)/MgAl-LDH is 82.84 m^(2)·g^(-)1,which is 2.34 times that of CoFe_(2)O_(4).CoFe_(2)O_(4)/MgAl-LDH has a saturation magnetic strength of 22.24 A·m^(2)·kg^(-1) facilitating efficient solid-liquid separation.The composite catalyst was employed to activate peroxymonosulfate(PMS)for the efficient degradation of tetracycline hydrochloride(TCH).It is found that the catalytic performance of CoFe_(2)O_(4)/MgAl-LDH significantly exceeds that of CoFe_(2)O_(4).The maximum TCH removal reaches 98.2%under the optimal conditions([TCH]=25 mg/L,[PMS]=1.5 mmol/L,CoFe_(2)O_(4)/MgAl-LDH=0.20 g/L,pH 7,and T=25℃).Coexisting ions in the solution,such as SO_(4)^(2-),Cl-,H_(2)PO_(4)^(-),and CO_(3)^(2-),have a negligible effect on catalytic performance.Cyclic tests demonstrate that the catalytic performance of CoFe_(2)O_(4)/MgAl-LDH remains 67.2%after five cycles.Mechanism investigations suggest that O_(2)^(•-)and ^(1)O_(2) produced by CoFe_(2)O_(4)/MgAl-LDH play a critical role in the catalytic degradation.
文摘This study investigates the effect of apple extract on CoFe_(2)O_(4) nanoparticles synthesized via a green self-ignition method.High resolution transmission electron microscope(HRTEM)showed nanometric particles with varied shapes,while X-ray diffraction(XRD)and Rietveld refinement confirmed a facecentered cubic(Fd3m)structure.Mössbauer spectroscopy revealed a Zeeman sextet pattern with only Fe^(3+) ions.Ultra violet vissible nearinfrared(UV-Vis-NIR)spectra indicated strong absorbance in the visible and NIR regions,suggesting optoelectronic potential.The nanoparticles demonstrated high photo-Fenton catalytic efficiency,degrading 96.88%of Methylene Blue under visible light.They also exhibited 100%adsorption capacities for Cr^(3+) and Pb^(2+),making them effective for water treatment.These properties were attributed to a large surface area(347.04 m2/g),mesoporous structure,and mixed spinel phase.ANOVA and Tukey’s honestly significant difference(HSD)tests confirmed that contact time and adsorbent dosage significantly affected pollutant removal.Additionally,strong antimicrobial activity highlighted their biotechnological relevance.The inclusion of apple extract enhanced structural and functional features,expanding application prospects in spin valves,magnetic recording,refrigeration,microwave technologies(C to Ku bands),optoelectronics,and biotechnology.Future work should explore the photo-Fenton degradation mechanism and optimize synthesis for scalable production,aiming to maximize their industrial utility.
文摘Supported metal catalysts are the backbone of heterogeneous catalysis,playing a crucial role in the modern chemical industry.Metal-support interactions(MSIs)are known important in determining the catalytic performance of supported metal catalysts.This is particularly true for single-atom catalysts(SACs)and pseudo-single-atom catalysts(pseudo-SACs),where all metal atoms are dispersed on,and interact directly with the support.Consequently,the MSI of SACs and pseudo-SACs are theoretically more sensitive to modulation compared to that of traditional nanoparticle catalysts.In this work,we experimentally demonstrated this hypothesis by an observed size-dependent MSI modulation.We fabricated CoFe_(2)O_(4) supported Pt pseudo-SACs and nanoparticle catalysts,followed by a straightforward water treatment process.It was found that the covalent strong metal-support interaction(CMSI)in pseudo-SACs can be weakened,leading to a significant activity improvement in methane combustion reaction.This finding aligns with our recent observation of CoFe_(2)O_(4) supported Pt SACs.By contrast,the MSI in Pt nanoparticle catalyst was barely affected by the water treatment,giving rise to almost unchanged catalytic performance.This work highlights the critical role of metal size in determining the MSI modulation,offering a novel strategy for tuning the catalytic performance of SACs and pseudo-SACs by fine-tuning their MSIs.
文摘为降低电解水阳极的析氧反应过电位,采用一步水热法制备了泡沫镍基钴铁混合氧化物(CoFe2O4@NF)复合材料。采用XRD、SEM、TEM和XPS等方法对复合材料进行表征,并利用三电极体系对其电解水析氧催化性能进行了测试。结果显示:Co Fe_(2)O_(4)以颗粒的形式聚集成空心球结构生长于泡沫镍基底上,其中空心球的直径大约4μm,而CoFe2O4的粒径约为40 nm左右。在1 mol·L^(-1)KOH溶液中,CoFe_(2)O_(4)@NF复合材料仅需293 mV的过电位即可达到20 m A·cm^(-2)的电流密度,Tafel斜率为51 m V·dec^(-1)。经过1000次循环伏安扫描和10 h电流时间曲线测试后,其析氧性能依旧保持高稳定性,在析氧催化材料领域有着广阔的研究前景。
