Metallic interface engineering is a promising strategy to stabilize Zn anode via promoting Zn^(2+) uniform deposition.However,strong interactions between the coating and Zn^(2+) and sluggish transport of Zn^(2+) lead ...Metallic interface engineering is a promising strategy to stabilize Zn anode via promoting Zn^(2+) uniform deposition.However,strong interactions between the coating and Zn^(2+) and sluggish transport of Zn^(2+) lead to high anodic polarization.Here,we present a bio-inspired silk fibroin(SF)coating with amphoteric charges to construct an interface reversible electric field,which manipulates the transfer kinetics of Zn^(2+) and reduces anodic polarization.The alternating positively and negatively charged surface as a build-in driving force can expedite and homogenize Zn^(2+) flux via the inter-play between the charged coating and adsorbed ions,endowing the Zn-SF anode with low polarization voltage and stable plating/stripping.Experimental analyses with theo-retical calculations suggest that SF can facilitate the desolvation of[Zn(H_(2)O)_(6)]^(2+) and provide nucleation sites for uniform deposition.Consequently,the Zn-SF anode delivers a high-rate performance with low voltage polarization(83 mV at 20 mA cm^(−2)) and excellent stability(1500 h at 1 mA cm^(−2);500 h at 10 mA cm^(−2)),realizing exceptional cumulative capacity of 2.5 Ah cm^(−2).The full cell coupled with Zn_(x)V_(2)O_(5)·nH_(2)O(ZnVO)cathode achieves specific energy of~270.5/150.6 Wh kg^(−1)(at 0.5/10 A g^(−1))with-99.8% Coulombic efficiency and retains~80.3%(at 5.0 A g^(−1))after 3000 cycles.展开更多
Anodic oxygen evolution reaction(OER)is essential to participate in diverse renewable energy conversion and storage processes,while most OER electrocatalysts present satisfactory catalytic performance in only alkaline...Anodic oxygen evolution reaction(OER)is essential to participate in diverse renewable energy conversion and storage processes,while most OER electrocatalysts present satisfactory catalytic performance in only alkaline or acidic medium,limiting their practical applications in many aspects.Herein,we have designed and prepared Ir-CeO_(2)-C nanofibers(NFs)via an electrospinning and a relatively low-temperature calcination strategy for OER application in both alkaline and acidic conditions.Density functional theory(DFT)simulations demonstrate the high catalytic active sites of Ir atoms for OER,that the formation of Ir–O bonds at the interface between Ir and CeO_(2)can modulate the electron density of the relevant Ir atoms to promote the OER activity.In addition,the unique nanofibrous heterostructure increases the exposed active sites and promotes the electrical conductivity.Therefore,the prepared Ir-CeO_(2)-C nanofibrous catalyst delivers an excellent OER property in both alkaline and acidic solutions.Impressively,the overpotentials to reach 10 mA·cm^(−2)are only 279 and 283 mV in the alkaline and acidic electrolyte,respectively,with favorable long-term stabilities.In addition,the two-electrode overall water splitting set-ups equipped with Ir-CeO_(2)-C NFs as anode and commercial Pt/C as cathode provide a cell voltage of 1.54 and 1.53 V to drive 10 mA·cm^(−2)in the alkaline and acidic electrolyte,respectively,which are much lower than Pt/C||IrO_(2)and lots of transition metal oxides-based electrolyzers.This research presents an efficient means to design OER catalysts with superior properties in both alkaline and acidic solutions.展开更多
It is essential to develop efficient electrocatalysts to generate hydrogen from water electrolysis for hydrogen economy. In this work, platinum(Pt) and nickel(Ni) co-doped porous carbon nanofibers(Pt/NiPCNFs) with low...It is essential to develop efficient electrocatalysts to generate hydrogen from water electrolysis for hydrogen economy. In this work, platinum(Pt) and nickel(Ni) co-doped porous carbon nanofibers(Pt/NiPCNFs) with low Pt content were prepared via an electrospinning, carbonization and galvanic replacement reaction. Because of the high electrical conductivity, abundant electrochemical active sites and synergistic effect between Pt and Ni nanoparticles, the optimized Pt/Ni-PCNFs catalyst shows an excellent HER activity with overpotentials of 20 m V in 0.5 mol/L H_(2)SO_(4) and 46 m V in 1 mol/L KOH at a current density of10 m A/cm^(2). Furthermore, over 35-h long-term stability has been achieved without significant attenuation.This work provides a simple route to prepare highly efficient electrocatalysts for water splitting and has great prospects in the field of renewable energy.展开更多
基金This work is supported by the National Natural Science Foundation of China(Nos.22275066,521032089,21774046,51871107,52130101 and 52271217)Jilin Provincial Science and Technology Department(20210508046RQ and 20200801057GH)+1 种基金China Postdoctoral Science Foundation(2021T140253 and 2021M691188)the Applied Basic Research Program of Changchun Municipal Science and Technology Project(21ZY22).
文摘Metallic interface engineering is a promising strategy to stabilize Zn anode via promoting Zn^(2+) uniform deposition.However,strong interactions between the coating and Zn^(2+) and sluggish transport of Zn^(2+) lead to high anodic polarization.Here,we present a bio-inspired silk fibroin(SF)coating with amphoteric charges to construct an interface reversible electric field,which manipulates the transfer kinetics of Zn^(2+) and reduces anodic polarization.The alternating positively and negatively charged surface as a build-in driving force can expedite and homogenize Zn^(2+) flux via the inter-play between the charged coating and adsorbed ions,endowing the Zn-SF anode with low polarization voltage and stable plating/stripping.Experimental analyses with theo-retical calculations suggest that SF can facilitate the desolvation of[Zn(H_(2)O)_(6)]^(2+) and provide nucleation sites for uniform deposition.Consequently,the Zn-SF anode delivers a high-rate performance with low voltage polarization(83 mV at 20 mA cm^(−2)) and excellent stability(1500 h at 1 mA cm^(−2);500 h at 10 mA cm^(−2)),realizing exceptional cumulative capacity of 2.5 Ah cm^(−2).The full cell coupled with Zn_(x)V_(2)O_(5)·nH_(2)O(ZnVO)cathode achieves specific energy of~270.5/150.6 Wh kg^(−1)(at 0.5/10 A g^(−1))with-99.8% Coulombic efficiency and retains~80.3%(at 5.0 A g^(−1))after 3000 cycles.
基金the National Natural Science Foundation of China(Nos.51973079 and 21673093)the Natural Science Foundation of Fujian Province(No.2020J01147)+1 种基金Research Foundation of Academy of Carbon Neutrality of Fujian Normal University(No.TZH2022-05)Minjiang Scholar and Startup Fund for High-level Talent at Fujian Normal University.
文摘Anodic oxygen evolution reaction(OER)is essential to participate in diverse renewable energy conversion and storage processes,while most OER electrocatalysts present satisfactory catalytic performance in only alkaline or acidic medium,limiting their practical applications in many aspects.Herein,we have designed and prepared Ir-CeO_(2)-C nanofibers(NFs)via an electrospinning and a relatively low-temperature calcination strategy for OER application in both alkaline and acidic conditions.Density functional theory(DFT)simulations demonstrate the high catalytic active sites of Ir atoms for OER,that the formation of Ir–O bonds at the interface between Ir and CeO_(2)can modulate the electron density of the relevant Ir atoms to promote the OER activity.In addition,the unique nanofibrous heterostructure increases the exposed active sites and promotes the electrical conductivity.Therefore,the prepared Ir-CeO_(2)-C nanofibrous catalyst delivers an excellent OER property in both alkaline and acidic solutions.Impressively,the overpotentials to reach 10 mA·cm^(−2)are only 279 and 283 mV in the alkaline and acidic electrolyte,respectively,with favorable long-term stabilities.In addition,the two-electrode overall water splitting set-ups equipped with Ir-CeO_(2)-C NFs as anode and commercial Pt/C as cathode provide a cell voltage of 1.54 and 1.53 V to drive 10 mA·cm^(−2)in the alkaline and acidic electrolyte,respectively,which are much lower than Pt/C||IrO_(2)and lots of transition metal oxides-based electrolyzers.This research presents an efficient means to design OER catalysts with superior properties in both alkaline and acidic solutions.
基金financially supported by the National Natural Science Foundation of China(51973079)the Science and Technology Development Plan of Jilin Province,China(20220402008GH)。
文摘设计分层异质结构作为一种经济且高效的催化剂,以实现水分解的电子和界面工程,是能源存储与转化中的一个有意义的决策.在这项工作中,通过静电纺丝-碳化-电沉积的策略,制备了负载在嵌入Co纳米颗粒的碳纤维上的非晶态NiFeS纳米片(Co-C/NiFeS纳米纤维)催化剂.该催化剂具有优异的析氧反应(OER)活性,在1 mol L^(-1)KOH溶液中,在10 mA cm^(-2)下的过电位为233 mV,Tafel斜率为53.1 mV dec^(-1),同时还具有良好的析氢反应活性.此外,由Co-C/NiFeS纳米纤维作为阳极,商用Pt/C作为阴极构建的碱性Pt/C‖Co-C/NiFeS电解槽在10 mA cm^(-2)下实现1.48 V的低电池电压,优于基准Pt/C‖RuO_(2)电解槽和许多其他报道的电解槽.作为双功能电催化剂,Co-C/NiFeS‖Co-C/NiFeS自身组装的电解槽表现出70小时的长期稳定性,显著优于Pt/C‖RuO_(2)电解槽.该催化剂显著的OER性能得益于Co-C纳米纤维核与非晶NiFeS纳米片鞘组成的明显分层异质结构以及生成的高导电碳纤维基底,这些结构特征赋予该材料丰富的暴露活性位点、良好的导电性和坚固的结构稳定性.因此,这项工作提出了一种简单且有效的方法来制备具有优异电催化性能的非贵金属基催化剂,以用于实际的能量转换和存储.
基金financially supported by the National Natural Science Foundation of China (Nos. 5197307, 219875084)the Project of the Education Department of Jilin Province, China (No. JJKH20211047KJ)。
文摘It is essential to develop efficient electrocatalysts to generate hydrogen from water electrolysis for hydrogen economy. In this work, platinum(Pt) and nickel(Ni) co-doped porous carbon nanofibers(Pt/NiPCNFs) with low Pt content were prepared via an electrospinning, carbonization and galvanic replacement reaction. Because of the high electrical conductivity, abundant electrochemical active sites and synergistic effect between Pt and Ni nanoparticles, the optimized Pt/Ni-PCNFs catalyst shows an excellent HER activity with overpotentials of 20 m V in 0.5 mol/L H_(2)SO_(4) and 46 m V in 1 mol/L KOH at a current density of10 m A/cm^(2). Furthermore, over 35-h long-term stability has been achieved without significant attenuation.This work provides a simple route to prepare highly efficient electrocatalysts for water splitting and has great prospects in the field of renewable energy.
