98 工程科学学报，第42卷.第1期 [6]Fang Y H,Liu Z P.Mechanism and tafel lines of electro-oxidation Soc,2012,134(41)16959 of water to oxygen on RuO (110).J Am Chem Soc,2010. [20]Bajdich M,Garcia-Mota M,Voivodic A,et al.Theoretical 132(51):18214 investigation of the activity of cobalt oxides for the [7]Jiang J,Zhang A L,Li LL,et al.Nickel-cobalt layered double electrochemical oxidation of water.J Am Chem Soc,2013, hydroxide nanosheets as high-performance electrocatalyst for 135(36):13521 oxygen evolution reaction.J Power Sources,2015,278:445 [21]Zhang J T,Zhao Z H,Xia Z H,et al.A metal-free bifunctional [8] Reier T,Pawolek Z,Cherevko S,et al.Molecular insight in electrocatalyst for oxygen reduction and oxygen evolution structure and activity of highly efficient,low-Ir Ir-Ni oxide reactions.Nat Nanotechnol,2015,10:444 catalysts for electrochemical water splitting (OER).JAm Chem [22]Yang H B,Miao J W,Hung S F,et al.Identification of catalytic S0c,2015,137(40):13031 sites for oxygen reduction and oxygen evolution in N-doped [9]Song F.Hu X L.Exfoliation of layered double hydroxides for graphene materials:development of highly efficient metal-free enhanced oxygen evolution catalysis.Nat Commn,2014,5:4477 bifunctional electrocatalyst.SciAdv,2016,2(4):e1501122 [10]Nong H N,Gan L,Willinger E,et al.IrOx core-shell nanocatalysts [23]Miner E M,Dinca M.Metal-organic frameworks:Evolved oxygen for cost-and energy-efficient electrochemical water splitting.Chem evolution catalysts.Nat Energy,2016,1(12):16186 Sc2014.5(8):2955 [24]Zhou H C,Long J R,Yaghi O M.Introduction to metal-organic [11]Li X Z,Fang YY,Lin X Q,et al.MOF derived Co;O frameworks.Chem Rev,2012,112(2):673 nanoparticles embedded in N-doped mesoporous carbon [25]Zhou H C J,Kitagawa S.Metal-organic frameworks (MOFs). layer/MWCNT hybrids:extraordinary bi-functional Chem Soc Rev,.2014,43(16):5415 electrocatalysts for OER and ORR.J Mater Chem A,2015,3(33): [26]Dilpazir S,He H Y,Li Z H,et al.Cobalt single atoms immobilized 17392 N-doped carbon nanotubes for enhanced bifunctional catalysis [12]Li LL,Tian T,Jiang J,et al.Hierarchically porous CoO toward oxygen reduction and oxygen evolution reactions.ACS architectures with honeycomb-like structures for efficient oxygen Appl Energy Mater,2018,1(7):3283 generation from electrochemical water splitting.Power Sources, [27]Liu S W,Zhang H M,Zhao Q.et al.Metal-organic framework 2015,294:103 derived nitrogen-doped porous carbon @graphene sandwich-like [13]Jiao L,Zhou Y X,Jiang H L.Metal-organic framework-based structured composites as bifunctional electrocatalysts for oxygen CoP/reduced graphene oxide:high-performance bifunctional electrocatalyst for overall water splitting.Chem Sci,2016,7(3): reduction and evolution reactions.Carbon,2016,106:74 1690 [28]Choi C H,Park S H,Woo S I.Binary and temary doping of [14]Zhao Y,Nakamura R,Kamiya K,et al.Nitrogen-doped carbon nitrogen,boron,and phosphorus into carbon for enhancing nanomaterials as non-metal electrocatalysts for water oxidation. electrochemical oxygen reduction activity.ACS Nano,2012,6(8): Nat Commun,2013,4:2390 7084 [15]Louie M W,Bell A T.An investigation of thin-film Ni-Fe oxide [29]Hou Y,Wen Z H,Cui S M,et al.An advanced nitrogen-doped catalysts for the electrochemical evolution of oxygen.JAm Chem graphene/cobalt-embedded porous carbon polyhedron hybrid for S0c,2013,135(33):12329 efficient catalysis of oxygen reduction and water splitting.Adv [16]Liang YY,Wang H L,Zhou J G,et al.Covalent hybrid of spinel Funct Mater,2015,25(6):872 manganese-cobalt oxide and graphene as advanced oxygen redu- [30]Nethravathi C,Rajamathi M.Chemically modified graphene sheets ction electrocatalysts.J Am Chem Soc,2012,134(7):3517 produced by the solvothermal reduction of colloidal dispersions of [17]Kim J K,Yang W,Salim J,et al.Li-water battery with oxygen graphite oxide.Carbon,2008,46(14):1994 dissolved in water as a cathode.J Electrochem Soc,2014,161(3) [31]Stankovich S,Dikin D A,Piner R D,et al.Synthesis of graphene- A285 based nanosheets via chemical reduction of exfoliated graphite [18]Chou N H,Ross P N,Bell A T,et al.Comparison of cobalt-based oxide.Carbon,2007,45(7):1558 nanoparticles as electrocatalysts for water oxidation.Chem Sus [32]Zhu Y P.Liu Y P,Ren T Z,et al.Self-supported cobalt phosphide Chem,2011,4(11):1566 mesoporous nanorod arrays:a flexible and bifunctional electrode [19]Lee S W,Carlton C,Risch M,et al.The nature of lithium battery for highly active electrocatalytic water reduction and oxidation materials under oxygen evolution reaction conditions.JAm Chem Ady Funct Mater,2015,25(47):7337Fang Y H, Liu Z P. Mechanism and tafel lines of electro-oxidation of  water  to  oxygen  on  RuO2 (110). J Am Chem Soc,  2010, 132（51）: 18214 [6] Jiang  J,  Zhang  A  L,  Li  L  L,  et  al.  Nickel-cobalt  layered  double hydroxide  nanosheets  as  high-performance  electrocatalyst  for oxygen evolution reaction. J Power Sources, 2015, 278: 445 [7] Reier  T,  Pawolek  Z,  Cherevko  S,  et  al.  Molecular  insight  in structure  and  activity  of  highly  efficient,  low-Ir  Ir-Ni  oxide catalysts  for  electrochemical  water  splitting  (OER). J Am Chem Soc, 2015, 137（40）: 13031 [8] Song  F,  Hu  X  L.  Exfoliation  of  layered  double  hydroxides  for enhanced oxygen evolution catalysis. Nat Commun, 2014, 5: 4477 [9] Nong H N, Gan L, Willinger E, et al. IrOx core-shell nanocatalysts for cost- and energy-efficient electrochemical water splitting. Chem Sci, 2014, 5（8）: 2955 [10] Li  X  Z,  Fang  Y  Y,  Lin  X  Q,  et  al.  MOF  derived  Co3O4 nanoparticles  embedded  in  N-doped  mesoporous  carbon layer/MWCNT  hybrids:  extraordinary  bi-functional electrocatalysts for OER and ORR. J Mater Chem A, 2015, 3（33）: 17392 [11] Li  L  L,  Tian  T,  Jiang  J,  et  al.  Hierarchically  porous  Co3O4 architectures  with  honeycomb-like  structures  for  efficient  oxygen generation from electrochemical water splitting. J Power Sources, 2015, 294: 103 [12] Jiao  L,  Zhou  Y  X,  Jiang  H  L.  Metal-organic  framework-based CoP/reduced  graphene  oxide:  high-performance  bifunctional electrocatalyst  for  overall  water  splitting. Chem Sci,  2016,  7（3）: 1690 [13] Zhao  Y,  Nakamura  R,  Kamiya  K,  et  al.  Nitrogen-doped  carbon nanomaterials  as  non-metal  electrocatalysts  for  water  oxidation. Nat Commun, 2013, 4: 2390 [14] Louie M W, Bell A T. An investigation of thin-film Ni‒Fe oxide catalysts for the electrochemical evolution of oxygen. J Am Chem Soc, 2013, 135（33）: 12329 [15] Liang Y Y, Wang H L, Zhou J G, et al. Covalent hybrid of spinel manganese ‒cobalt oxide and graphene as advanced oxygen redu￾ction electrocatalysts. J Am Chem Soc, 2012, 134（7）: 3517 [16] Kim  J  K,  Yang  W,  Salim  J,  et  al.  Li-water  battery  with  oxygen dissolved in water as a cathode. J Electrochem Soc, 2014, 161（3）: A285 [17] Chou N H, Ross P N, Bell A T, et al. Comparison of cobalt-based nanoparticles  as  electrocatalysts  for  water  oxidation. Chem Sus Chem, 2011, 4（11）: 1566 [18] Lee S W, Carlton C, Risch M, et al. The nature of lithium battery materials under oxygen evolution reaction conditions. J Am Chem [19] Soc, 2012, 134（41）: 16959 Bajdich  M,  García-Mota  M,  Vojvodic  A,  et  al.  Theoretical investigation  of  the  activity  of  cobalt  oxides  for  the electrochemical  oxidation  of  water. J Am Chem Soc,  2013, 135（36）: 13521 [20] Zhang  J  T,  Zhao  Z  H,  Xia  Z  H,  et  al.  A  metal-free  bifunctional electrocatalyst  for  oxygen  reduction  and  oxygen  evolution reactions. Nat Nanotechnol, 2015, 10: 444 [21] Yang H B, Miao J W, Hung S F, et al. Identification of catalytic sites  for  oxygen  reduction  and  oxygen  evolution  in  N-doped graphene  materials:  development  of  highly  efficient  metal-free bifunctional electrocatalyst. Sci Adv, 2016, 2（4）: e1501122 [22] Miner E M, Dincă M. Metal-organic frameworks: Evolved oxygen evolution catalysts. Nat Energy, 2016, 1（12）: 16186 [23] Zhou  H  C,  Long  J  R,  Yaghi  O  M.  Introduction  to  metal-organic frameworks. Chem Rev, 2012, 112（2）: 673 [24] Zhou  H  C  J,  Kitagawa  S.  Metal-organic  frameworks  (MOFs). Chem Soc Rev, 2014, 43（16）: 5415 [25] Dilpazir S, He H Y, Li Z H, et al. Cobalt single atoms immobilized N-doped  carbon  nanotubes  for  enhanced  bifunctional  catalysis toward  oxygen  reduction  and  oxygen  evolution  reactions. ACS Appl Energy Mater, 2018, 1（7）: 3283 [26] Liu  S  W,  Zhang  H  M,  Zhao  Q,  et  al.  Metal-organic  framework derived  nitrogen-doped  porous  carbon@graphene  sandwich-like structured  composites  as  bifunctional  electrocatalysts  for  oxygen reduction and evolution reactions. Carbon, 2016, 106: 74 [27] Choi  C  H,  Park  S  H,  Woo  S  I.  Binary  and  ternary  doping  of nitrogen,  boron,  and  phosphorus  into  carbon  for  enhancing electrochemical oxygen reduction activity. ACS Nano, 2012, 6（8）: 7084 [28] Hou  Y,  Wen  Z  H,  Cui  S  M,  et  al.  An  advanced  nitrogen-doped graphene/cobalt-embedded  porous  carbon  polyhedron  hybrid  for efficient  catalysis  of  oxygen  reduction  and  water  splitting. Adv Funct Mater, 2015, 25（6）: 872 [29] Nethravathi C, Rajamathi M. Chemically modified graphene sheets produced by the solvothermal reduction of colloidal dispersions of graphite oxide. Carbon, 2008, 46（14）: 1994 [30] Stankovich S, Dikin D A, Piner R D, et al. Synthesis of graphene￾based  nanosheets  via  chemical  reduction  of  exfoliated  graphite oxide. Carbon, 2007, 45（7）: 1558 [31] Zhu Y P, Liu Y P, Ren T Z, et al. Self-supported cobalt phosphide mesoporous  nanorod  arrays:  a  flexible  and  bifunctional  electrode for  highly  active  electrocatalytic  water  reduction  and  oxidation. Adv Funct Mater, 2015, 25（47）: 7337 [32] · 98 · 工程科学学报，第 42 卷，第 1 期