Exploring effective iridium(Ir)-based electrocatalysts with stable iridium centers is highly desirable for oxygen evolution reaction(OER).Herein,we regulated the incorporation manner of Ir in Co_(3)O_(4)support to sta...Exploring effective iridium(Ir)-based electrocatalysts with stable iridium centers is highly desirable for oxygen evolution reaction(OER).Herein,we regulated the incorporation manner of Ir in Co_(3)O_(4)support to stabilize the Ir sites for effective OER.When anchored on the surface of Co_(3)O_(4)in the form of Ir(OH)_6 species,the created Ir-OH-Co interface leads to a limited stability and poor acidic OER due to Ir leaching.When doped into Co_(3)O_(4)lattice,the analyses of X-ray absorption spectroscopy,in-situ Raman,and OER measurements show that the partially replacement of Co in Co_(3)O_(4)by Ir atoms inclines to cause strong electronic effect and activate lattice oxygen in the presence of Ir-O-Co interface,and simultaneously master the reconstruction effect to mitigate Ir dissolution,realizing the improved OER activity and stability in alkaline and acidic environments.As a result,Ir_(lat)@Co_(3)O_(4)with Ir loading of 3.67 wt%requires 294±4 mV/285±3 mV and 326±2 mV to deliver 10 mA cm^(-2)in alkaline(0.1 M KOH/1.0 M KOH)and acidic(0.5 M H_(2)SO_(4))solution,respectively,with good stability.展开更多
Iridium(Ir)-based materials are the only commercializable class of anode electrocatalysts for acidic oxygen evolution reaction(OER)in proton exchange membrane water electrolyzers(PEMWE).Intending to large-scale implem...Iridium(Ir)-based materials are the only commercializable class of anode electrocatalysts for acidic oxygen evolution reaction(OER)in proton exchange membrane water electrolyzers(PEMWE).Intending to large-scale implement of PEMWE,it is urgent to improve their OER performances for reducing the usage of high-cost Ir element.Herein,we report an elaborate synthesis of ultrathin Ir/WO_(x)hybrid nanosheets equipped with abundant 2D-confined heterointerfaces(denoted as Ir/WO_(x)NSs),which are composed of ultrathin Ir nanograins embedded in amorphous WO_(x)matrix,to substantially enhance the acidic OER.The Ir/WO_(x)NSs achieve a notable mass activity of 2.34 A mg Ir^(−1)at an overpotential of 300 mV,which is approximately 11.1 and 9.8 times higher than those of Ir NSs and commercial Ir/C,respectively.The 2D-confined interactions between crystalline Ir nanograins and amorphous WO_(x)matrix establish synergistic bifunctional sites and efficient charge transfer interfaces,which effectively accelerate the initial hydrolysis dissociation step.Moreover,on interfacial Ir atoms,the adsorption of*O and subsequent formation of*OOH intermediates are thermodynamically facilitated,making the OER process more favorable through the adsorbate evolution mechanism.Finally,the Ir/WO_(x)NSs based PEMWE demonstrates a low cell voltage of only 1.71 V to deliver 1.0 A cm^(−2)current density as well as an outstanding long-term durability,realizing efficient and stable green hydrogen production.This work highlights the engineering of 2D-confined metal-oxide interfacial electrocatalysts for efficient energy conversion applications.展开更多
目的使用传统指标和FT-IR技术评价乳剂稳定性。方法通过两步乳化法制备O/W乳剂,以平均粒径、离心稳定常数及表面张力3个指标对乳剂进行表征。用浸渍法分别测定水相、油相和乳剂的傅里叶变换红外光谱(FT-IR)图,再用软件origin 7.5对水相...目的使用传统指标和FT-IR技术评价乳剂稳定性。方法通过两步乳化法制备O/W乳剂,以平均粒径、离心稳定常数及表面张力3个指标对乳剂进行表征。用浸渍法分别测定水相、油相和乳剂的傅里叶变换红外光谱(FT-IR)图,再用软件origin 7.5对水相和乳剂的羟基峰进行去卷积,根据最小二乘法拟合出组成羟基峰的高斯曲线。结果 2个乳剂的平均粒径分别为155.9 nm和138.5 nm,离心稳定常数分别为0.377和0.561,表面张力分别为54.22 m N/m和64.80 m N/m;制成乳剂后,FT-IR图中油相的信号峰几乎完全消失,而水相和乳剂的FT-IR图中,羟基峰均由6条高斯曲线组成,乳剂中5条高斯曲线的峰位对比于水相都发生了蓝移。结论定量的传统指标和定性的FT-IR技术相结合,可以更好地评价乳剂的稳定性。展开更多
This paper introduces the current practice of building a network of institutional repositories(IRs) at Chinese Academy of Sciences(CAS), which is named CAS IR Grid.National Science Library(NSL) of CAS plays a leading ...This paper introduces the current practice of building a network of institutional repositories(IRs) at Chinese Academy of Sciences(CAS), which is named CAS IR Grid.National Science Library(NSL) of CAS plays a leading role in the construction, promotion and implementation of CAS IR Grid. It aims to promote each institute of CAS to build IR of its own, and finally form the IR network of CAS institutes. NSL's experience is introduced in coordinating and supporting institutes' building of their respective IRs and promoting IR services by adopting collaborative and progressive development strategies. Achievements made during the development of CAS IR Grid are described and challenges for its future development are discussed. The authors aim to provide best practices for developing a network of institutional repositories in research institute settings, which can serve as a practical reference to other institutions engaged in the similar task.展开更多
基金supported by the National Natural Science Foundation of China(52150410409).
文摘Exploring effective iridium(Ir)-based electrocatalysts with stable iridium centers is highly desirable for oxygen evolution reaction(OER).Herein,we regulated the incorporation manner of Ir in Co_(3)O_(4)support to stabilize the Ir sites for effective OER.When anchored on the surface of Co_(3)O_(4)in the form of Ir(OH)_6 species,the created Ir-OH-Co interface leads to a limited stability and poor acidic OER due to Ir leaching.When doped into Co_(3)O_(4)lattice,the analyses of X-ray absorption spectroscopy,in-situ Raman,and OER measurements show that the partially replacement of Co in Co_(3)O_(4)by Ir atoms inclines to cause strong electronic effect and activate lattice oxygen in the presence of Ir-O-Co interface,and simultaneously master the reconstruction effect to mitigate Ir dissolution,realizing the improved OER activity and stability in alkaline and acidic environments.As a result,Ir_(lat)@Co_(3)O_(4)with Ir loading of 3.67 wt%requires 294±4 mV/285±3 mV and 326±2 mV to deliver 10 mA cm^(-2)in alkaline(0.1 M KOH/1.0 M KOH)and acidic(0.5 M H_(2)SO_(4))solution,respectively,with good stability.
基金supported by the National Natural Science Foundation of China(U24A20563,22171093,22201085)the Natural Science Foundation of Fujian Province(2022J02008)the Scientific Research Funds of Huaqiao University.
文摘Iridium(Ir)-based materials are the only commercializable class of anode electrocatalysts for acidic oxygen evolution reaction(OER)in proton exchange membrane water electrolyzers(PEMWE).Intending to large-scale implement of PEMWE,it is urgent to improve their OER performances for reducing the usage of high-cost Ir element.Herein,we report an elaborate synthesis of ultrathin Ir/WO_(x)hybrid nanosheets equipped with abundant 2D-confined heterointerfaces(denoted as Ir/WO_(x)NSs),which are composed of ultrathin Ir nanograins embedded in amorphous WO_(x)matrix,to substantially enhance the acidic OER.The Ir/WO_(x)NSs achieve a notable mass activity of 2.34 A mg Ir^(−1)at an overpotential of 300 mV,which is approximately 11.1 and 9.8 times higher than those of Ir NSs and commercial Ir/C,respectively.The 2D-confined interactions between crystalline Ir nanograins and amorphous WO_(x)matrix establish synergistic bifunctional sites and efficient charge transfer interfaces,which effectively accelerate the initial hydrolysis dissociation step.Moreover,on interfacial Ir atoms,the adsorption of*O and subsequent formation of*OOH intermediates are thermodynamically facilitated,making the OER process more favorable through the adsorbate evolution mechanism.Finally,the Ir/WO_(x)NSs based PEMWE demonstrates a low cell voltage of only 1.71 V to deliver 1.0 A cm^(−2)current density as well as an outstanding long-term durability,realizing efficient and stable green hydrogen production.This work highlights the engineering of 2D-confined metal-oxide interfacial electrocatalysts for efficient energy conversion applications.
文摘目的使用传统指标和FT-IR技术评价乳剂稳定性。方法通过两步乳化法制备O/W乳剂,以平均粒径、离心稳定常数及表面张力3个指标对乳剂进行表征。用浸渍法分别测定水相、油相和乳剂的傅里叶变换红外光谱(FT-IR)图,再用软件origin 7.5对水相和乳剂的羟基峰进行去卷积,根据最小二乘法拟合出组成羟基峰的高斯曲线。结果 2个乳剂的平均粒径分别为155.9 nm和138.5 nm,离心稳定常数分别为0.377和0.561,表面张力分别为54.22 m N/m和64.80 m N/m;制成乳剂后,FT-IR图中油相的信号峰几乎完全消失,而水相和乳剂的FT-IR图中,羟基峰均由6条高斯曲线组成,乳剂中5条高斯曲线的峰位对比于水相都发生了蓝移。结论定量的传统指标和定性的FT-IR技术相结合,可以更好地评价乳剂的稳定性。
基金supported by the Knowledge Innovation Program of Chinese Academy of Sciences (CAS) and the West Light Foundation of CAS
文摘This paper introduces the current practice of building a network of institutional repositories(IRs) at Chinese Academy of Sciences(CAS), which is named CAS IR Grid.National Science Library(NSL) of CAS plays a leading role in the construction, promotion and implementation of CAS IR Grid. It aims to promote each institute of CAS to build IR of its own, and finally form the IR network of CAS institutes. NSL's experience is introduced in coordinating and supporting institutes' building of their respective IRs and promoting IR services by adopting collaborative and progressive development strategies. Achievements made during the development of CAS IR Grid are described and challenges for its future development are discussed. The authors aim to provide best practices for developing a network of institutional repositories in research institute settings, which can serve as a practical reference to other institutions engaged in the similar task.
