The use of renewable energy for hydrogen production through water electrolysis is a critical pathway for green hydrogen generation.Compared to pure water electrolysis,direct electrolysis of seawater offers several adv...The use of renewable energy for hydrogen production through water electrolysis is a critical pathway for green hydrogen generation.Compared to pure water electrolysis,direct electrolysis of seawater offers several advantages,such as raw material availability and application diversity.However,the complex composition of seawater presents significant technical challenges,particularly the competitive chloride oxidation reaction(ClOR)at the anode,which leads to equipment corrosion[1].展开更多
Electrolysis of seawater offers a highly promising and sustainable route to attain carbon-neutral hydrogen energy without demanding on high-purity water resource.However,it is severely limited by the undesirable chlor...Electrolysis of seawater offers a highly promising and sustainable route to attain carbon-neutral hydrogen energy without demanding on high-purity water resource.However,it is severely limited by the undesirable chlorine oxidation reaction(ClOR)on the anode and the releasing toxic chlorine species,inducing anode corrosion and multiple pollutions to reduce the efficiency and sustainability of this technology.The effective way is to limit the overpotential of oxygen evolution reaction(OER)below 480 mV and thus suppress the ClOR.Herein,we demonstrate that nitrogen-doped carbon dots strongly coupled NiFe layered double hydroxide nanosheet arrays on Ni foam(N-CDs/NiFe-LDH/NF)can efficiently facilitate OER with an ultralow overpotential of 260 mV to deliver the geometric current density of 100 mA·cm^(−2)and a Tafel slope of as low as 43.4 mV·dec−1 in 1.0 M KOH.More importantly,the N-CDs/NiFe-LDH/NF electrode at 100 mA·cm^(−2)shows overpotentials of 285 and 273 mV,respectively,by utilizing 1.0 M KOH with 0.5 M NaCl and 1.0 M KOH with 1.0 M NaCl as the simulated seawater,well avoid triggering ClOR.Notably,despite the complex environment of real seawater,N-CDs/NiFe-LDH/NF still effectively promotes alkaline seawater(1.0 M KOH+seawater)electrolysis with a lifetime longer than 50 and 20 h,respectively,in 1.0 M KOH and alkaline seawater electrolytes.The investigation result reveals that M–N–C bonding generated between N-CDs and NiFe-LDH intrinsically optimizes the charge transfer efficiency,further promoting the OER kinetics.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.22202205 and 22209170)XMIREM Autonomously Deployment Project,China(Nos.2023CX14,2023GG01)+4 种基金Self-deployment Project Research Program of Haixi Institutes,Chinese Academy of Sciences(Nos.CXZX-2022-GH03,CXZX-2024-JQ02)Major Science and Technology Program of Xiamen,China(No.3502Z20231054)Natural Science Foundation of Fujian Province,China(Grant Nos.2022J01502 and 2024J01185)STS Program of the Chinese Academy of Sciences,China(No.2023T3071)Natural Science Foundation of Xiamen,China(No.3502Z20227256).
文摘The use of renewable energy for hydrogen production through water electrolysis is a critical pathway for green hydrogen generation.Compared to pure water electrolysis,direct electrolysis of seawater offers several advantages,such as raw material availability and application diversity.However,the complex composition of seawater presents significant technical challenges,particularly the competitive chloride oxidation reaction(ClOR)at the anode,which leads to equipment corrosion[1].
基金the National Natural Science Foundation of China(Nos.52122308,21905253,and 51973200)the Natural Science Foundation of Henan(No.202300410372).
文摘Electrolysis of seawater offers a highly promising and sustainable route to attain carbon-neutral hydrogen energy without demanding on high-purity water resource.However,it is severely limited by the undesirable chlorine oxidation reaction(ClOR)on the anode and the releasing toxic chlorine species,inducing anode corrosion and multiple pollutions to reduce the efficiency and sustainability of this technology.The effective way is to limit the overpotential of oxygen evolution reaction(OER)below 480 mV and thus suppress the ClOR.Herein,we demonstrate that nitrogen-doped carbon dots strongly coupled NiFe layered double hydroxide nanosheet arrays on Ni foam(N-CDs/NiFe-LDH/NF)can efficiently facilitate OER with an ultralow overpotential of 260 mV to deliver the geometric current density of 100 mA·cm^(−2)and a Tafel slope of as low as 43.4 mV·dec−1 in 1.0 M KOH.More importantly,the N-CDs/NiFe-LDH/NF electrode at 100 mA·cm^(−2)shows overpotentials of 285 and 273 mV,respectively,by utilizing 1.0 M KOH with 0.5 M NaCl and 1.0 M KOH with 1.0 M NaCl as the simulated seawater,well avoid triggering ClOR.Notably,despite the complex environment of real seawater,N-CDs/NiFe-LDH/NF still effectively promotes alkaline seawater(1.0 M KOH+seawater)electrolysis with a lifetime longer than 50 and 20 h,respectively,in 1.0 M KOH and alkaline seawater electrolytes.The investigation result reveals that M–N–C bonding generated between N-CDs and NiFe-LDH intrinsically optimizes the charge transfer efficiency,further promoting the OER kinetics.
