一步水热法制备电解水析氧反应Ni_(3)S_(2)@Mo_(2)S_(3)高效催化剂

One-step hydrothermal method toward preparation of Ni_(3)S_(2)@Mo_(2)S_(3) high efficient catalyst for oxygen evolution reaction in water electrolysis

采用一步水热法,由泡沫钼镍合金同时提供钼源和镍源在泡沫钼镍合金表面原位制备了Ni_(3)S_(2)@Mo_(2)S_(3),并将其直接作为自支撑电极用于催化碱性介质中的电解水析氧反应(OER)。利用多种表征测试技术研究了样品的形貌、组成、OER电催化性能,结果显示:Ni_(3)S_(2)@Mo_(2)S_(3)呈纳米板形貌,由六方Ni_(3)S_(2)和单斜Mo_(2)S_(3)按5∶1的比例复合而成;在1 mol·L^(-1)KOH溶液中,Ni_(3)S_(2)@Mo_(2)S_(3)催化剂仅需要170 mV过电位就可达到10 mA·cm^(-2)电流密度(欧姆补偿后),且在50 h的稳定性测试期间性能基本无衰减,优于贵金属催化剂IrO_(2)以及文献报道的Ni-Mo基复合催化剂。Ni_(3)S_(2)@Mo_(2)S_(3)具有优异电催化性能的原因可归于不同过渡金属化合物的协同作用、原位生长自支撑、电化学活性面积大以及液下疏气性等因素。

The Ni_(3)S_(2)@Mo_(2)S_(3)self-supported catalyst for oxygen evolution reaction in water electrolysis was in situ synthesized on MoNi foam(MNF)by one-step hydrothermal method with MNF as the sources of Ni and Mo.The morphology,composition and OER electrocatalytic performance of the as-prepared catalyst were characterized by the corresponding characterization techniques and electrochemical methods.The catalyst was consisted of irregular nano-slabs with the composition of hexagonal Ni_(3)S_(2)and monoclinic Mo_(2)S_(3)in a ratio of 5∶1.The as-prepared Ni_(3)S_(2)@Mo_(2)S_(3)only needed an overpotential of 170 mV(after IR compensation)to drive a current density of 10 mA·cm^(-2)in 1 mol·L^(-1)KOH with negligible degradation during the 50 h stability test,which was superior to the commercial catalyst IrO2 and other Ni-Mo based catalysts reported.The excellent electrocatalytic performance of Ni_(3)S_(2)@Mo_(2)S_(3)can be attributed to the synergistic effect of different transition metal compounds,self-supporting in situ growth,large electrochemically active area,and aerophobicity under liquid.