电控离子交换技术(electrochemically switched ion exchange,ESIX)是将电活性离子交换材料(EXIMs)沉积或涂覆在导电基底上,通过电化学控制导电基底上活性材料氧化还原状态实现目标离子置入与释放,从而实现离子的分离。该技术具有痕量...电控离子交换技术(electrochemically switched ion exchange,ESIX)是将电活性离子交换材料(EXIMs)沉积或涂覆在导电基底上,通过电化学控制导电基底上活性材料氧化还原状态实现目标离子置入与释放,从而实现离子的分离。该技术具有痕量提取、无二次污染、速率可控、高选择性等优点。通过共沉淀法制备Ni Fe Mn LDH,并将其与碳纳米管(CNTs)、聚偏二氟乙烯(PVDF)混合涂覆到石墨板上,制得NiFeMn LDH/CNTs/PVDF膜电极。NiFeMn LDH层板上具有丰富的羟基官能团,可与W(Ⅵ)发生羟基配位;层间的阴离子与W(Ⅵ)进行离子交换,可为W(Ⅵ)提供丰富的活性位点。在ESIX系统中,膜电极对W(Ⅵ)的吸附容量可达122.10 mg·g^(-1),且W(Ⅵ)与Mo(Ⅵ)、Cl^(-)、■分离因子(■)分别为1.25、19.60、35.80,实现了W(Ⅵ)选择性分离。此外,该膜电极具有优异的循环稳定性,为钨的高效分离提供了新的方向。展开更多
The poor electronic conductivity of metal-organic framework(MOF)materials hinders their direct application in the field of electrocatalysis in fuel cells.Herein,we proposed a strategy of embedding carbon nanotubes(CNT...The poor electronic conductivity of metal-organic framework(MOF)materials hinders their direct application in the field of electrocatalysis in fuel cells.Herein,we proposed a strategy of embedding carbon nanotubes(CNTs)during the growth process of MOF crystals,synthesizing a metalloporphyrin-based MOF catalyst TCPPCo-MOF-CNT with a unique CNT-intercalated MOF structure.Physical characterization revealed that the CNTs enhance the overall conductivity while retaining the original characteristics of the MOF and metalloporphyrin.Simultaneously,the insertion of CNTs generated adequate mesopores and created a hierarchical porous structure that enhances mass transfer efficiency.X-ray photoelectron spectroscopic analysis confirmed that the C atom in CNT changed the electron cloud density on the catalytic active center Co,optimizing the electronic structure.Consequently,the E_(1/2) of the TCPPCo-MOF-CNT catalyst under neutral conditions reached 0.77 V(vs.RHE),outperforming the catalyst without CNTs.When the TCPPCo-MOF-CNT was employed as the cathode catalyst in assembling microbial fuel cells(MFCs)with Nafion-117 as the proton exchange membrane,the maxi-mum power density of MFCs reached approximately 500 mW·m^(-2).展开更多
文摘电控离子交换技术(electrochemically switched ion exchange,ESIX)是将电活性离子交换材料(EXIMs)沉积或涂覆在导电基底上,通过电化学控制导电基底上活性材料氧化还原状态实现目标离子置入与释放,从而实现离子的分离。该技术具有痕量提取、无二次污染、速率可控、高选择性等优点。通过共沉淀法制备Ni Fe Mn LDH,并将其与碳纳米管(CNTs)、聚偏二氟乙烯(PVDF)混合涂覆到石墨板上,制得NiFeMn LDH/CNTs/PVDF膜电极。NiFeMn LDH层板上具有丰富的羟基官能团,可与W(Ⅵ)发生羟基配位;层间的阴离子与W(Ⅵ)进行离子交换,可为W(Ⅵ)提供丰富的活性位点。在ESIX系统中,膜电极对W(Ⅵ)的吸附容量可达122.10 mg·g^(-1),且W(Ⅵ)与Mo(Ⅵ)、Cl^(-)、■分离因子(■)分别为1.25、19.60、35.80,实现了W(Ⅵ)选择性分离。此外,该膜电极具有优异的循环稳定性,为钨的高效分离提供了新的方向。
基金the financial support from the National Natural Science Foundation of China(No.22178307)China Southern Power Grid(Grant Nos.0470002022030103HX00002-01).
文摘The poor electronic conductivity of metal-organic framework(MOF)materials hinders their direct application in the field of electrocatalysis in fuel cells.Herein,we proposed a strategy of embedding carbon nanotubes(CNTs)during the growth process of MOF crystals,synthesizing a metalloporphyrin-based MOF catalyst TCPPCo-MOF-CNT with a unique CNT-intercalated MOF structure.Physical characterization revealed that the CNTs enhance the overall conductivity while retaining the original characteristics of the MOF and metalloporphyrin.Simultaneously,the insertion of CNTs generated adequate mesopores and created a hierarchical porous structure that enhances mass transfer efficiency.X-ray photoelectron spectroscopic analysis confirmed that the C atom in CNT changed the electron cloud density on the catalytic active center Co,optimizing the electronic structure.Consequently,the E_(1/2) of the TCPPCo-MOF-CNT catalyst under neutral conditions reached 0.77 V(vs.RHE),outperforming the catalyst without CNTs.When the TCPPCo-MOF-CNT was employed as the cathode catalyst in assembling microbial fuel cells(MFCs)with Nafion-117 as the proton exchange membrane,the maxi-mum power density of MFCs reached approximately 500 mW·m^(-2).
