Crystalline-amorphous M@MN_x(M=Co,Fe,Ni)encapsulated in nitrogen-doped carbon for enhanced efficient and durable hydrogen evolution reaction  

作　　者：Yang Yang Xiao-Chuan Duan Shao-Hui Guo Xian-Ming Zhang 

机构地区：[1]College of Materials Science and Engineering,College of Chemistry,Key Laboratory of Interface Science and Engineering in Advanced Materials,Taiyuan University of Technology,Yuci,030600,China

出　　处：《Rare Metals》2024年第4期1547-1556,共10页稀有金属（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(No.91961201);the China Postdoctoral Science Foundation(No.2022M722344);Shanxi"1331"Project。

摘　　要：Developing earth-abundant electrocatalysts for hydrogen evolution reaction(HER)is important for the sustainable energy economy.Herein,efficient and stable heterocatalysts consisting of crystalline-amorphous M@MN_(x)(M=Co,Fe,Ni)encapsulated in N-doped carbon layers supported with N-doped graphene sheets(denoted as M@MN_(x)@NC-NG)are synthesized by facile hydrothermal reaction and nitridation process.During the nitriding process,metal ions in M(tzbc)_2(H_(2)O)_4(tzbc=4-(1H-1,2,4-triazol-1-yl)benzoic acid)complexes are reduced to crystalline M cores,accompanied by the formation of amorphous MN_(x)shells;the tzbc ligands are insitu carbonized to form outermost N-doped carbon(NC)layers that connect with inner MN_(x)via M-N-C motifs inherited from the complex precursors and inhibit the transition of MN_(x)from amorphous to crystalline phase.The Co@CoN_(x)@NC-NG catalyst exhibits excellent HER activity with small overpotentials of 45 and 64 mV at a cathode current density of 10 mA·cm^(-2)and low Tafel slopes of 40 and 85 mV·dec^(-1)in 0.5 mol·L^(-1)H_(2)SO_4 and1.0 mol·L^(-1)KOH electrolytes,respectively.The Co@CoN_(x)@NC-NG retains 97%of the initial overpotential after 100,000 s in both acidic and alkaline media.Such outstanding HER performance originates from the crystalline-amorphous Co@CoN_(x)that redistributes electrons around the heterointerfaces,facilitating the conversion process of H^(+)/H_(2)O to hydrogen and thereby promoting HER kinetics.The outermost NC layers serve as the armor of Co@CoN_(x),and graphene nanosheets act as carriers of egg-like Co@CoN_(x)@NC and conduction paths for electron shuttles,ensuring stable and continuous electrocatalytic hydrogen production.

关 键 词：Hydrogen evolution reaction ELECTROCATALYSTS Iron group metals HETEROJUNCTION Crystalline-amorphous structure 

分 类 号：TB34[一般工业技术—材料科学与工程] O643.36[理学—物理化学] TQ116.2[理学—化学]