The fabrication of bifunctional electrocatalysts for hydrogen and oxygen evolution in aqueous environment has far-reaching significance.Especially,reasonable interface process regulation toward heterogeneous composite...The fabrication of bifunctional electrocatalysts for hydrogen and oxygen evolution in aqueous environment has far-reaching significance.Especially,reasonable interface process regulation toward heterogeneous composites can make full use of the active sites and improve the electrocatalytic activity.In this study,we designed and synthesized NiS_(2)-MoS_(2)-based heterogeneous composites as efficient and stable electrocatalysts for hydrogen and oxygen evolution in alkaline electrolyte.The heterostructure was obtained by one-step hydrothermal ulfurization operation towards polymolybdate-based metal-organic complex.The composition and nanostructures can be tailored by modulating experiment parameter,realizing the phase-controlled synthesis and interface regulation:(1)High-percentage of 1T-MoS_(2)can be achieved via selecting appropriate vulcanization time and thiourea concentration,benifiting for the higher electroconductivity and more active sites;(2)Regular and orderly vulcanization time promotes the gradual growth and aggregation of nanosheets;(3)The existence of nickel hydroxide improves the electrocatalytic stability for oxygen production performance.The optimized heterogeneous interfaces provide sufficient active sites and accelerate electron transfer.Consequently,the optimal heterogeneous nanosheets present low overpotentials of 33 and 122 m V at the catalytic current densities of 10 m A/cm2for HER and OER,respectively.展开更多
A spinel oxide NiCo204 prepared by thermal decomposition is of very high activity for the oxygen evolution reaction(OER)in alkaline solution.The oxygen evolution overpotential on NiCo204 is 0.252-0.262V in 10 M NaOH s...A spinel oxide NiCo204 prepared by thermal decomposition is of very high activity for the oxygen evolution reaction(OER)in alkaline solution.The oxygen evolution overpotential on NiCo204 is 0.252-0.262V in 10 M NaOH solution at 343K and current density 100 mAcm^(-2).展开更多
Transition metal phosphides(TMPs)have exhibited decent performance in an oxygen evolution reaction(OER),which is a kinetic bottleneck in many energy storages and conversion systems.Most reported catalysts are composed...Transition metal phosphides(TMPs)have exhibited decent performance in an oxygen evolution reaction(OER),which is a kinetic bottleneck in many energy storages and conversion systems.Most reported catalysts are composed of three or fewer metallic components.The inherent complexity of multicomponent TMPs with more than four metallic components hinders their investigation in rationally designing the structure and,more importantly,comprehending the component-activity correlation.Through hydrothermal growth and subsequent phosphor-ization,we reported a facile strategy for combining TMPs with tunable elemental compositions(Ni,Fe,Mn,Co,Cu)on a two-dimensional ti-tanium carbide(MXene)flake.The obtained TMPs/MXene hybrid nanostructures demonstrate homogeneously distributed elements.They ex-hibit high electrical conductivity and strong interfacial interaction,resulting in an accelerated reaction kinetics and long-term stability.The res-ults of different component catalysts’OER performance show that NiFeMnCoP/MXene is the most active catalyst,with a low overpotential of 240 mV at 10 mA·cm−2,a small Tafel slope of 41.43 mV·dec−1,and a robust long-term electrochemical stability.According to the electrocata-lytic mechanism investigation,the enhanced NiFeMnCoP/MXene OER performance is due to the strong synergistic effect of the multi-ele-mental composition.Our work,therefore,provides a scalable synthesis route for multi-elemental TMPs and a valuable guideline for efficient MXene-supported catalysts design.展开更多
The controllable synthesis of oxygen evolution reaction(OER)electrocatalyst is an urgent need to advance the develop-ment of sustainable energy conversion and storage.However,the OER efficiency in acidic media is seri...The controllable synthesis of oxygen evolution reaction(OER)electrocatalyst is an urgent need to advance the develop-ment of sustainable energy conversion and storage.However,the OER efficiency in acidic media is seriously hindered by slow reaction kinetics.The traditional acidic OER electrocatalysts are more prone to be oxidized and corroded as results of unstable carrier structures and variable electronic states of active species.Herein,a high-performing biochar aerogel(BA)based electrocatalyst were realistically designed and synthetized via joint utilization of the terrestrial lignin and seaweed polysaccharide as carbon sources.Originating from the induction effect of"egg-box"structure in alginate and the self-template effect of lignosulfonate,the BA decorated with Ru/RuS_(2)particles was synthesized triumphantly.The as-synthesized electrocatalyst required a low overpotential of 228 mV to attain 10 mA cm^(−2)in 0.5 M H_(2)SO_(4)and exhibited a good stability for over 12,000 s.The good activity was strongly dependent on the assembled unique two-dimensional/three-dimensional(2D/3D)channels in carbon aerogels.Notably,the numerous defective sites at carbon could strongly interact with the Ru/RuS_(2)heterojunction for remarkably enhancing the catalytic activity and stability of whole catalytic system in acidic media.This work puts forward a novel and effective strategy towards the enhancement of the acidic OER process by rational regu-lations of the BA and the coupling effect in micro-interface.展开更多
Hybrid materials are attracting intensive attention for their applications in electronics, photoelectronics, LEDs, field-effect transistors, etc. Engineering new hybrid materials and further exploiting their new funct...Hybrid materials are attracting intensive attention for their applications in electronics, photoelectronics, LEDs, field-effect transistors, etc. Engineering new hybrid materials and further exploiting their new functions will be significant for future science and technique development. In this work, alternatively stacked self-assembled CoAl LDH/MoS2 nanohybrid has been successfully synthesized by an exfoliation-flocculation method from positively charged CoAl LDH nanosheets（CoAl-NS） with negatively charged MoS2 nanosheets（MoS2-NS）. The CoAl LDH/MoS2 hybrid material exhibits an enhanced catalytic performance for oxygen evolution reaction（OER） compared with original constituents of CoAl LDH nanosheets and MoS2 nanosheets. The enhanced OER catalytic performance of CoAl LDH/MoS2 is demonstrated to be due to the improved electron transfer, more exposed catalytic active sites, and accelerated oxygen evolution reaction kinetics.展开更多
Transition metal-based layered double hydroxides(LDHs)have been capable of working efficiently as catalysts in the basic oxygen evolution reaction(OER)for sustaining hydrogen production of alkaline water electrolysis....Transition metal-based layered double hydroxides(LDHs)have been capable of working efficiently as catalysts in the basic oxygen evolution reaction(OER)for sustaining hydrogen production of alkaline water electrolysis.Nevertheless,exploring new LDH-based electrocatalysts featuring both remarkable activity and good stability is still in high demand,which is pivotal for comprehensive understanding and impressive improvement of the sluggish OER kinetics.Here,a series of bimetallic(Co and Mo)LDH arrays were designed and fabricated via a facile and controlled strategy by incorporating a Mo source into presynthesized Co-based metal-organic framework(MOF)arrays on carbon cloth(CC),named as ZIF-67/CC arrays.We found that tuning the Mo content resulted in gradual differences in the structural properties,surface morphology,and chemical states of the resulting catalysts,namely CoMox-LDH/CC(x representing the added weight of the Mo source).Gratifyingly,the best-performing CoMo_(0.20)-LDH/CC electrocatalyst demonstrates a low overpotential of only 226 mV and high stability at a current density of 10 mA·cm^(−2),which is superior to most LDH-based OER catalysts reported previously.Furthermore,it only required 1.611 V voltage to drive the overall water splitting device at the current density of 10 mA·cm^(−2).The present study represents a significant advancement in the development and applications of new OER catalysts.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.22271021,21971024)Liao Ning Revitalization Talents Program(No.XLYC1902011)Research Foundation of Education Bureau of Liaoning Province(No.LJKQZ20222290)。
文摘The fabrication of bifunctional electrocatalysts for hydrogen and oxygen evolution in aqueous environment has far-reaching significance.Especially,reasonable interface process regulation toward heterogeneous composites can make full use of the active sites and improve the electrocatalytic activity.In this study,we designed and synthesized NiS_(2)-MoS_(2)-based heterogeneous composites as efficient and stable electrocatalysts for hydrogen and oxygen evolution in alkaline electrolyte.The heterostructure was obtained by one-step hydrothermal ulfurization operation towards polymolybdate-based metal-organic complex.The composition and nanostructures can be tailored by modulating experiment parameter,realizing the phase-controlled synthesis and interface regulation:(1)High-percentage of 1T-MoS_(2)can be achieved via selecting appropriate vulcanization time and thiourea concentration,benifiting for the higher electroconductivity and more active sites;(2)Regular and orderly vulcanization time promotes the gradual growth and aggregation of nanosheets;(3)The existence of nickel hydroxide improves the electrocatalytic stability for oxygen production performance.The optimized heterogeneous interfaces provide sufficient active sites and accelerate electron transfer.Consequently,the optimal heterogeneous nanosheets present low overpotentials of 33 and 122 m V at the catalytic current densities of 10 m A/cm2for HER and OER,respectively.
文摘A spinel oxide NiCo204 prepared by thermal decomposition is of very high activity for the oxygen evolution reaction(OER)in alkaline solution.The oxygen evolution overpotential on NiCo204 is 0.252-0.262V in 10 M NaOH solution at 343K and current density 100 mAcm^(-2).
基金the National Nat-ural Science Foundation of China(No.51771132)the Open Fund Project of Qinghai Minzu University-Nanoma-terials and Nanotechnology Team&Platform(No.2021-QHMU-PI-nano-KF01).
文摘Transition metal phosphides(TMPs)have exhibited decent performance in an oxygen evolution reaction(OER),which is a kinetic bottleneck in many energy storages and conversion systems.Most reported catalysts are composed of three or fewer metallic components.The inherent complexity of multicomponent TMPs with more than four metallic components hinders their investigation in rationally designing the structure and,more importantly,comprehending the component-activity correlation.Through hydrothermal growth and subsequent phosphor-ization,we reported a facile strategy for combining TMPs with tunable elemental compositions(Ni,Fe,Mn,Co,Cu)on a two-dimensional ti-tanium carbide(MXene)flake.The obtained TMPs/MXene hybrid nanostructures demonstrate homogeneously distributed elements.They ex-hibit high electrical conductivity and strong interfacial interaction,resulting in an accelerated reaction kinetics and long-term stability.The res-ults of different component catalysts’OER performance show that NiFeMnCoP/MXene is the most active catalyst,with a low overpotential of 240 mV at 10 mA·cm−2,a small Tafel slope of 41.43 mV·dec−1,and a robust long-term electrochemical stability.According to the electrocata-lytic mechanism investigation,the enhanced NiFeMnCoP/MXene OER performance is due to the strong synergistic effect of the multi-ele-mental composition.Our work,therefore,provides a scalable synthesis route for multi-elemental TMPs and a valuable guideline for efficient MXene-supported catalysts design.
基金the National Natural Science Foundation of China(No.32101451)the Shandong Provincial Natural Science Foundation(No.ZR2019BC007)+2 种基金the Postdoctoral Science Foundation of China(No.2018M632626)State Key Laboratory of Bio-Fibers and Eco-Textiles(Qingdao University)(No.ZKT31)the Taishan Scholar Program of Shandong Province.
文摘The controllable synthesis of oxygen evolution reaction(OER)electrocatalyst is an urgent need to advance the develop-ment of sustainable energy conversion and storage.However,the OER efficiency in acidic media is seriously hindered by slow reaction kinetics.The traditional acidic OER electrocatalysts are more prone to be oxidized and corroded as results of unstable carrier structures and variable electronic states of active species.Herein,a high-performing biochar aerogel(BA)based electrocatalyst were realistically designed and synthetized via joint utilization of the terrestrial lignin and seaweed polysaccharide as carbon sources.Originating from the induction effect of"egg-box"structure in alginate and the self-template effect of lignosulfonate,the BA decorated with Ru/RuS_(2)particles was synthesized triumphantly.The as-synthesized electrocatalyst required a low overpotential of 228 mV to attain 10 mA cm^(−2)in 0.5 M H_(2)SO_(4)and exhibited a good stability for over 12,000 s.The good activity was strongly dependent on the assembled unique two-dimensional/three-dimensional(2D/3D)channels in carbon aerogels.Notably,the numerous defective sites at carbon could strongly interact with the Ru/RuS_(2)heterojunction for remarkably enhancing the catalytic activity and stability of whole catalytic system in acidic media.This work puts forward a novel and effective strategy towards the enhancement of the acidic OER process by rational regu-lations of the BA and the coupling effect in micro-interface.
基金financially supported by NNSFC(No.21025104,21271171,and 91022018)
文摘Hybrid materials are attracting intensive attention for their applications in electronics, photoelectronics, LEDs, field-effect transistors, etc. Engineering new hybrid materials and further exploiting their new functions will be significant for future science and technique development. In this work, alternatively stacked self-assembled CoAl LDH/MoS2 nanohybrid has been successfully synthesized by an exfoliation-flocculation method from positively charged CoAl LDH nanosheets（CoAl-NS） with negatively charged MoS2 nanosheets（MoS2-NS）. The CoAl LDH/MoS2 hybrid material exhibits an enhanced catalytic performance for oxygen evolution reaction（OER） compared with original constituents of CoAl LDH nanosheets and MoS2 nanosheets. The enhanced OER catalytic performance of CoAl LDH/MoS2 is demonstrated to be due to the improved electron transfer, more exposed catalytic active sites, and accelerated oxygen evolution reaction kinetics.
基金the financial support of the Fundamental Research Funds for the Central Universities(No.40120631)the National Natural Science Foundation of China(No.52202291)for the support.+1 种基金C.C.acknowledges the financial support of Natural Science Foundation of Hubei Province(No.2022CFB388)the Natural Science Foundation of Hainan Province of China(No.623MS068).
文摘Transition metal-based layered double hydroxides(LDHs)have been capable of working efficiently as catalysts in the basic oxygen evolution reaction(OER)for sustaining hydrogen production of alkaline water electrolysis.Nevertheless,exploring new LDH-based electrocatalysts featuring both remarkable activity and good stability is still in high demand,which is pivotal for comprehensive understanding and impressive improvement of the sluggish OER kinetics.Here,a series of bimetallic(Co and Mo)LDH arrays were designed and fabricated via a facile and controlled strategy by incorporating a Mo source into presynthesized Co-based metal-organic framework(MOF)arrays on carbon cloth(CC),named as ZIF-67/CC arrays.We found that tuning the Mo content resulted in gradual differences in the structural properties,surface morphology,and chemical states of the resulting catalysts,namely CoMox-LDH/CC(x representing the added weight of the Mo source).Gratifyingly,the best-performing CoMo_(0.20)-LDH/CC electrocatalyst demonstrates a low overpotential of only 226 mV and high stability at a current density of 10 mA·cm^(−2),which is superior to most LDH-based OER catalysts reported previously.Furthermore,it only required 1.611 V voltage to drive the overall water splitting device at the current density of 10 mA·cm^(−2).The present study represents a significant advancement in the development and applications of new OER catalysts.
