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
It is still challenging for exploring high-active photocatalysts to efficiently remove levofloxacin(LFX)by activating peroxymonosulfate(PMS).Herein,we constructed a novel Z scheme ZnFe_(2)O_(4)/g-C_(3)N_(4)/CQDs(ZCC)h...It is still challenging for exploring high-active photocatalysts to efficiently remove levofloxacin(LFX)by activating peroxymonosulfate(PMS).Herein,we constructed a novel Z scheme ZnFe_(2)O_(4)/g-C_(3)N_(4)/CQDs(ZCC)heterojunction by anchoring ZnFe_(2)O_(4)on tubular-like g-C_(3)N_(4)induced by CQDs(denoted as CNC)using microwave-assisted thermal methods.The ZCC exhibits the highest photocatalytic activity in activating PMS for LFX degradation,endowing a removal rate~95.3%,which is 4.8 and 7.3 times that of pure ZnFe_(2)O_(4)(19.8%)and g-C_(3)N_(4)(13.1%),separately.The enhanced photocatalytic activity of ZCC can be attributed to the distinctive morphology of CNC,enhanced light response,increased specific surface area and abundant pore structure.Besides,the formed Z scheme heterojunction and CQDs acting as a transmission bridge of the photogenerated charges(e−and h+)can accelerate transfer and inhibit recombination of e−and h+.Radical capture experiments and electron spin resonance(ESR)measurements revealed that SO4•-and O2•-play a predominant role in degradation process of LFX.Liquid chromatography-mass spectrometry(LC-MS)was applied to identify intermediates and propose feasible degradation pathways of LFX.In conclusion,this study presents a promising strategy for regulating the photocatalytic activity of g-C_(3)N_(4)by simultaneously integrating CQDs induction and Z scheme heterojunction construction.展开更多
开发用于高级氧化技术的廉价易得、高效稳定的催化剂对于水处理至关重要.以水滑石/壳聚糖为前驱体开发了一种新型“原位沉淀-煅烧”法制备磁性氮掺杂碳负载CoFe_(2)O_(4)-CoO催化剂(LDO/NC).该催化剂用于活化过一硫酸盐(PMS)降解四环素(...开发用于高级氧化技术的廉价易得、高效稳定的催化剂对于水处理至关重要.以水滑石/壳聚糖为前驱体开发了一种新型“原位沉淀-煅烧”法制备磁性氮掺杂碳负载CoFe_(2)O_(4)-CoO催化剂(LDO/NC).该催化剂用于活化过一硫酸盐(PMS)降解四环素(TC),表现出明显优于单纯水滑石氧化物(LDO)和氮掺杂碳(NC)的催化活性.这是由于壳聚糖作为碳源和氮源的原位引入成功抑制了钴铁金属氧化物团聚,同时N原子的掺杂增强电子转移,协同催化提高活性.研究了催化剂组成、催化剂用量、PMS用量和初始pH值等因素对TC降解效率的影响规律.最佳条件下(PMS用量0.4 g L^(-1),LDO/NC用量0.5 g L^(-1),pH=5),30 min内TC的降解率和总碳去除率分别达到97.8%和81.0%.该催化剂可磁性回收且循环使用五次以上,稳定性保持良好.提供了一种用于催化PMS氧化处理制药废水的绿色催化剂.展开更多
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.
基金Project(32272823) supported by the National Natural Science Foundation of ChinaProject(145309315) supported by the Research Foundation of Education Bureau of Heilongjiang Province of ChinaProject(YSTSXK202309) supported by the Plant Food Processing Technology Advantages Characteristic Discipline “Science and Technology Research” Special Project in Heilongjiang Province,China。
文摘It is still challenging for exploring high-active photocatalysts to efficiently remove levofloxacin(LFX)by activating peroxymonosulfate(PMS).Herein,we constructed a novel Z scheme ZnFe_(2)O_(4)/g-C_(3)N_(4)/CQDs(ZCC)heterojunction by anchoring ZnFe_(2)O_(4)on tubular-like g-C_(3)N_(4)induced by CQDs(denoted as CNC)using microwave-assisted thermal methods.The ZCC exhibits the highest photocatalytic activity in activating PMS for LFX degradation,endowing a removal rate~95.3%,which is 4.8 and 7.3 times that of pure ZnFe_(2)O_(4)(19.8%)and g-C_(3)N_(4)(13.1%),separately.The enhanced photocatalytic activity of ZCC can be attributed to the distinctive morphology of CNC,enhanced light response,increased specific surface area and abundant pore structure.Besides,the formed Z scheme heterojunction and CQDs acting as a transmission bridge of the photogenerated charges(e−and h+)can accelerate transfer and inhibit recombination of e−and h+.Radical capture experiments and electron spin resonance(ESR)measurements revealed that SO4•-and O2•-play a predominant role in degradation process of LFX.Liquid chromatography-mass spectrometry(LC-MS)was applied to identify intermediates and propose feasible degradation pathways of LFX.In conclusion,this study presents a promising strategy for regulating the photocatalytic activity of g-C_(3)N_(4)by simultaneously integrating CQDs induction and Z scheme heterojunction construction.
文摘开发用于高级氧化技术的廉价易得、高效稳定的催化剂对于水处理至关重要.以水滑石/壳聚糖为前驱体开发了一种新型“原位沉淀-煅烧”法制备磁性氮掺杂碳负载CoFe_(2)O_(4)-CoO催化剂(LDO/NC).该催化剂用于活化过一硫酸盐(PMS)降解四环素(TC),表现出明显优于单纯水滑石氧化物(LDO)和氮掺杂碳(NC)的催化活性.这是由于壳聚糖作为碳源和氮源的原位引入成功抑制了钴铁金属氧化物团聚,同时N原子的掺杂增强电子转移,协同催化提高活性.研究了催化剂组成、催化剂用量、PMS用量和初始pH值等因素对TC降解效率的影响规律.最佳条件下(PMS用量0.4 g L^(-1),LDO/NC用量0.5 g L^(-1),pH=5),30 min内TC的降解率和总碳去除率分别达到97.8%和81.0%.该催化剂可磁性回收且循环使用五次以上,稳定性保持良好.提供了一种用于催化PMS氧化处理制药废水的绿色催化剂.
