氧电催化一般涉及到氧还原反应(ORR)和氧析出应(OER),是诸如燃料电池,金属空气电池和水电解池等能源转换与存储技术的关键步骤.其中,可充电的金属锌空气电池具有较高的能量密度,开发成本较低,运行安全且环境友好.然而,开发并采用高效,...氧电催化一般涉及到氧还原反应(ORR)和氧析出应(OER),是诸如燃料电池,金属空气电池和水电解池等能源转换与存储技术的关键步骤.其中,可充电的金属锌空气电池具有较高的能量密度,开发成本较低,运行安全且环境友好.然而,开发并采用高效,低成本且储量丰富的催化材料代替贵金属基电催化剂,仍旧是现阶段尚未完全解决的问题和挑战.最近,金属有机框架(MOFs)以及碳基的金属有机框架衍生物作为高效电催化剂,因其超乎寻常的形貌,结构,组分和功能性的可调节能力,已经逐渐引起了广泛的关注和研究兴趣.因此,本文报道了一种泡沫镍负载的二维金属有机框架及其衍生物耦合阵列作为无粘结剂型ORR/OER双效催化剂,能够实现高比表面积,高电导率和高双功能性,同时避免了使用有机粘结剂的复杂制备过程和不可避免的电池性能影响.与传统设计不同,本文主要通过集成各司其职的不同功能组分并充分暴露电化学活性面积来提高双效电极的整体活性.电化学测试结果表明,耦合阵列电极(R-NCM)相比于MOFs阵列(NCM)和MOFs衍生物阵列(A-NCM)等对比电极,具有显著提高的双效氧电极性能,氧还原反应的起峰电位约为0.90 V,而氧析出反应电流密度达到100 m Acm-2时的过电势为319 m V.由于其在生长–热裂解–再生长过程中所具有的稳定的站立多级二维纳米片结构,所制备的双效氧电极材料表现出显著增强的双官能团性,电化学活性面积,反应动力学和稳定性,并可进一步用于可充电的金属锌空气电池(ZABs).考虑到制备过程的可行性与简洁性,所提出的生长–热裂解–再生长策略不仅能够用于耦合型分级纳米片阵列结构的合成,还能为设计开发相关能源电化学装置的高活性电极结构提供借鉴.展开更多
Although considerable research efforts have been devoted to the design and development of non-noble electrocatalysts for oxygen evolution reaction(OER), substantial enhancement of OER performance with commercial-scale...Although considerable research efforts have been devoted to the design and development of non-noble electrocatalysts for oxygen evolution reaction(OER), substantial enhancement of OER performance with commercial-scale water electrolysis remains a big challenge. This could result from the difficulties in detecting the intrinsic properties and overlooking the assembly process for electrochemical OER process. Here, we employ a microjet collision method to investigate the intrinsic OER activities of individual NiZnFeO_x entities with and without a moderate magnetic field. Our results demonstrate that single NiZnFeO_x nanoparticles(NPs) show the excellent OER performance with a lowest onset potential(~1.35 V vs. RHE) and a greatest magnetic enhancement(~118%) among bulk materials, single agglomerations and NPs. Furthermore, we explore the utility of theoretical investigation by density functional theory(DFT)calculations for studying OER process on NiZnFeO_x surfaces without and with spin alignment, indicating monodispersed NiZnFeO_xNPs with totally spin alignment facilitates the OER process under the external magnetic field. It is found that the well-dispersion of NiZnFeO_x NPs would increase the electrical conductivity and the surface spin state, resulting in promoting their OER activities. This work provides a test for uncovering the essential roles of NPs assembly to a significant promotion of their magnet-assisted OER.展开更多
Oxyge n vaca ncies impla ntation is an efficie nt way to adjust the physical and chemical properties of metal oxide nano materials to meet the requirements for particular applications.Through reasonable defects design...Oxyge n vaca ncies impla ntation is an efficie nt way to adjust the physical and chemical properties of metal oxide nano materials to meet the requirements for particular applications.Through reasonable defects design,oxyge-deficient metal oxides with excellent optical and electrical properties are widely applied for environmental protection and energy uses.This review discusses recent advances in synthetic approaches of oxygervdeficient metal oxides and their applications in photocatalysis,electrocatalysis,and energy storage devices.The perspectives of oxyge n?deficie nt metal oxides for increased en ergy dema nd and en vironme ntal sustai liability are also exami ned.展开更多
Electrocatalysts for oxygen reduction reactions(ORR)and oxygen evolution reactions(OER)are highly crucial and challenging toward the energy storage and conversion technologies such as fuel cells,metal-air batteries an...Electrocatalysts for oxygen reduction reactions(ORR)and oxygen evolution reactions(OER)are highly crucial and challenging toward the energy storage and conversion technologies such as fuel cells,metal-air batteries and water electrolysis.To replace noble-metal based catalysts and boost catalytic performance of carbon-based materials,we initially develop the nickel,phospho rus,sulfur and nitrogen co-modified mesoporous carbon(NiPS_(3)@NMC)as a bifunctional oxygen electrocatalyst.The perfo rmance for ORR(half-wave potential at 0.90 V)and OER(10 mA cm^(-2)at 1.48 V)surpasses those of Pt/C coupled with IrO_(2)catalysts and most of the non-precious metal based bifunctional electrocatalysts reported in related literature.Moreover,the electrochemical durability is also confirmed by accelerated durability tests(ADTs)and long-term chronoamperometry(CA)tests.We demonstrated that the interfacial effect between NiPS_(3)quantum sheets(QS s)and NMC substrates by thermal activation contributed to the enhanced oxygen electrode bifunctionality with more active sites,due to the electrons-donating from nickel,phosphorus and sulfur elements and relatively enriched pyridinic type N.Such excellent overall performance highlights the potential application of NiPS3 QSs and NMC composites as the materials on energy conversion and storage.展开更多
Defective TiO2 has attracted increasing attention for use in photocatalytic and electrochemical materials because of its narrowed band-gap and improved visible-light photocatalytic activity. However, a facile and effi...Defective TiO2 has attracted increasing attention for use in photocatalytic and electrochemical materials because of its narrowed band-gap and improved visible-light photocatalytic activity. However, a facile and efficient approach for obtaining defect-rich TiO2 still remains a challenge. Herein, we demonstrate such an approach to narrow its bandgap and improve visible-light absorption through implanting abundant defects by aerodynamic levitated laser annealing (ALLA) treatment. Note that the ALLA method not only provides rapid annealing, solidifying and cooling process, but also exhibits high efficiency for homogeneous and defective TiO2 nanoparticles. The laser-annealed TiO2 achieves a high hydrogen evolution rate of 8.54 mmol.h-1.g-1, excellent decomposition properties within 60 min, and outstanding recyclability and stability, all of which are superior to the corresponding properties of commercial P25.展开更多
文摘氧电催化一般涉及到氧还原反应(ORR)和氧析出应(OER),是诸如燃料电池,金属空气电池和水电解池等能源转换与存储技术的关键步骤.其中,可充电的金属锌空气电池具有较高的能量密度,开发成本较低,运行安全且环境友好.然而,开发并采用高效,低成本且储量丰富的催化材料代替贵金属基电催化剂,仍旧是现阶段尚未完全解决的问题和挑战.最近,金属有机框架(MOFs)以及碳基的金属有机框架衍生物作为高效电催化剂,因其超乎寻常的形貌,结构,组分和功能性的可调节能力,已经逐渐引起了广泛的关注和研究兴趣.因此,本文报道了一种泡沫镍负载的二维金属有机框架及其衍生物耦合阵列作为无粘结剂型ORR/OER双效催化剂,能够实现高比表面积,高电导率和高双功能性,同时避免了使用有机粘结剂的复杂制备过程和不可避免的电池性能影响.与传统设计不同,本文主要通过集成各司其职的不同功能组分并充分暴露电化学活性面积来提高双效电极的整体活性.电化学测试结果表明,耦合阵列电极(R-NCM)相比于MOFs阵列(NCM)和MOFs衍生物阵列(A-NCM)等对比电极,具有显著提高的双效氧电极性能,氧还原反应的起峰电位约为0.90 V,而氧析出反应电流密度达到100 m Acm-2时的过电势为319 m V.由于其在生长–热裂解–再生长过程中所具有的稳定的站立多级二维纳米片结构,所制备的双效氧电极材料表现出显著增强的双官能团性,电化学活性面积,反应动力学和稳定性,并可进一步用于可充电的金属锌空气电池(ZABs).考虑到制备过程的可行性与简洁性,所提出的生长–热裂解–再生长策略不仅能够用于耦合型分级纳米片阵列结构的合成,还能为设计开发相关能源电化学装置的高活性电极结构提供借鉴.
基金supported by the Major Research Project (No.92061108)the National Natural Science Foundation of China (No.22272052)+2 种基金Shanghai Municipal Science and Technology Major Project (No.2018SHZDZX03)Xiamen University Opening Project of PCOSS (No.201901)Yongjiang Talent Introduction Programme(No.2021A-115-G)。
文摘Although considerable research efforts have been devoted to the design and development of non-noble electrocatalysts for oxygen evolution reaction(OER), substantial enhancement of OER performance with commercial-scale water electrolysis remains a big challenge. This could result from the difficulties in detecting the intrinsic properties and overlooking the assembly process for electrochemical OER process. Here, we employ a microjet collision method to investigate the intrinsic OER activities of individual NiZnFeO_x entities with and without a moderate magnetic field. Our results demonstrate that single NiZnFeO_x nanoparticles(NPs) show the excellent OER performance with a lowest onset potential(~1.35 V vs. RHE) and a greatest magnetic enhancement(~118%) among bulk materials, single agglomerations and NPs. Furthermore, we explore the utility of theoretical investigation by density functional theory(DFT)calculations for studying OER process on NiZnFeO_x surfaces without and with spin alignment, indicating monodispersed NiZnFeO_xNPs with totally spin alignment facilitates the OER process under the external magnetic field. It is found that the well-dispersion of NiZnFeO_x NPs would increase the electrical conductivity and the surface spin state, resulting in promoting their OER activities. This work provides a test for uncovering the essential roles of NPs assembly to a significant promotion of their magnet-assisted OER.
基金This study was supported by the National Basic Research of China(No.2015CB932500)the National Natural Science Foundations of China(Nos.51788104,51661135025 and 51522207)S.S.thanks financial support from Innovation Foundation for Science and Technology of Shenzhen(Nos.JCYJ20170307153548350 and JCYJ20170817172150505).
文摘Oxyge n vaca ncies impla ntation is an efficie nt way to adjust the physical and chemical properties of metal oxide nano materials to meet the requirements for particular applications.Through reasonable defects design,oxyge-deficient metal oxides with excellent optical and electrical properties are widely applied for environmental protection and energy uses.This review discusses recent advances in synthetic approaches of oxygervdeficient metal oxides and their applications in photocatalysis,electrocatalysis,and energy storage devices.The perspectives of oxyge n?deficie nt metal oxides for increased en ergy dema nd and en vironme ntal sustai liability are also exami ned.
基金supported financially by the National Natural Science Foundation of China(Nos.51902027,61674019,51976143,61874014,61874013 and 61974011)the National Basic Research of China(No.2015CB932500)+1 种基金the Fundamental Research Funds for the Central Universities(No.2019RC20)the Fund of State Key Laboratory of Information Photonics and Optical Communications(Beijing University of Posts and Telecommunications,P.R.China)。
文摘Electrocatalysts for oxygen reduction reactions(ORR)and oxygen evolution reactions(OER)are highly crucial and challenging toward the energy storage and conversion technologies such as fuel cells,metal-air batteries and water electrolysis.To replace noble-metal based catalysts and boost catalytic performance of carbon-based materials,we initially develop the nickel,phospho rus,sulfur and nitrogen co-modified mesoporous carbon(NiPS_(3)@NMC)as a bifunctional oxygen electrocatalyst.The perfo rmance for ORR(half-wave potential at 0.90 V)and OER(10 mA cm^(-2)at 1.48 V)surpasses those of Pt/C coupled with IrO_(2)catalysts and most of the non-precious metal based bifunctional electrocatalysts reported in related literature.Moreover,the electrochemical durability is also confirmed by accelerated durability tests(ADTs)and long-term chronoamperometry(CA)tests.We demonstrated that the interfacial effect between NiPS_(3)quantum sheets(QS s)and NMC substrates by thermal activation contributed to the enhanced oxygen electrode bifunctionality with more active sites,due to the electrons-donating from nickel,phosphorus and sulfur elements and relatively enriched pyridinic type N.Such excellent overall performance highlights the potential application of NiPS3 QSs and NMC composites as the materials on energy conversion and storage.
基金This work is financially supported by the National Natural Science Foundation of China (Nos. 51471158, 51674232 and 51274182) and Beijing Natural Science Foundation (Nos. 2152032 and 2112039).
文摘Defective TiO2 has attracted increasing attention for use in photocatalytic and electrochemical materials because of its narrowed band-gap and improved visible-light photocatalytic activity. However, a facile and efficient approach for obtaining defect-rich TiO2 still remains a challenge. Herein, we demonstrate such an approach to narrow its bandgap and improve visible-light absorption through implanting abundant defects by aerodynamic levitated laser annealing (ALLA) treatment. Note that the ALLA method not only provides rapid annealing, solidifying and cooling process, but also exhibits high efficiency for homogeneous and defective TiO2 nanoparticles. The laser-annealed TiO2 achieves a high hydrogen evolution rate of 8.54 mmol.h-1.g-1, excellent decomposition properties within 60 min, and outstanding recyclability and stability, all of which are superior to the corresponding properties of commercial P25.