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探索新的催化活性物种和开发价格低廉、来源广泛的镍铁基电催化剂对实现高效电解水产氧有着重要意义.本文报道了一种通过阳极化镶嵌Fe_2O_3颗粒的Ni(OH)_2纳米片阵列,使其原位电化学转化成NiFe_2O_4-NiOOH纳米片阵列用于高效电解水产氧的复合催化剂.电化学产氧测试表明:这种复合材料催化剂在电流密度达到30 mA cm~(-2)时仅需240 mV的过电势,且只需要410 mV的过电势就可使电流密度达到3000mA cm~(-2).电化学原位拉曼光谱测试表明:这种镶嵌有Fe_2O_3颗粒的Ni(OH)_2纳米片中的Ni(OH)_2拥有更高的反应活性,从而使其不仅更容易氧化生成NiOOH,同时新生成的NiOOH可以在正电流的刺激下与Fe_2O_3颗粒反应原位生成非晶的NiFe_2O_4-NiOOH复合材料.该复合材料的高电化学产氧活性主要归因于NiFe_2O_4和NiOOH的协同作用,以及由于纳米片阵列结构所导致的超疏气与超亲水表面.这项工作不仅从全新的角度解读了镍铁基催化剂高电催化产氧活性的起源,同时还提供了一种温和的室温合成方法用以制备具有非晶结构的尖晶石类材料.此外,该项工作还有助于研究者关注异质催化剂在电催化过程中的物质转化行为,从而更好地设计和发展新型高效催化体系.
It is of great importance to explore new catalytically active species and to develop nickel iron-based electrocatalysts with low cost and wide range of sources for efficient electrolysis of aquatic oxygen.An Ni (OH) 2 nanosheet array with anodic polarization Fe_2O_3 particles is reported in this paper, The in-situ electrochemical conversion into NiFe2O4-NiOOH nanosheet arrays for the efficient electrolysis of aquatic oxygen composite catalysts electrochemical oxygen production test showed that the composite catalyst at current density reached 30 mA cm -2 The overpotential of 240 mV is required and the current density can reach 3000 mA cm -2 with only 410 mV overpotential.The results of electrochemical in situ Raman spectroscopy show that the Ni (OH) _2 nanosheets Ni (OH) _2 has higher reactivity, making it not only easier to oxidize to generate NiOOH, while the newly generated NiOOH can react with Fe_2O_3 particles to generate amorphous NiFe_2O_4 in situ under the stimulation of positive current -NiOOH composites.The high electrochemical oxygen evolution activity of the composites is mainly attributed to the synergistic effect of NiFe2O4 and NiOOH and the superhydrophobic and superhydrophilic surfaces due to the nanosheet array structure.This work not only from In the new perspective, the origin of high electrocatalytic oxygen production activity of nickel-iron-based catalysts is also explained, and a mild room-temperature synthesis method is also provided to prepare spinel materials with amorphous structure. In addition, Help researchers to pay attention to the heterogeneous catalyst in the electrocatalytic process of material conversion behavior, so as to better design and development of new and efficient catalytic system.