高熵磷化物双功能催化剂的制备及高效电解水性能

High-entropy Phosphide Bifunctional Catalyst:Preparation and Performance of Efficient Water Splitting

在电解水制氢过程中,析氢反应(HER)和析氧反应(OER)的缓慢电催化动力学限制了其能量转换效率。高熵材料具有独特的结构特征和优异的性能,是一种潜在的电解水催化剂,有可能取代传统的金属氧化物和贵金属。由于金属与非金属之间的不相容性,关于高熵化合物特别是高熵金属磷化物合成的报道很少。本研究以柠檬酸为络合剂、磷酸二氢铵为磷源,采用低温溶胶-凝胶法,通过添加不同组元金属合成了一系列以碳为基底的高熵合金磷化物纳米颗粒。在1 mol·L^(-1)的KOH介质中,FeCoNiMoCeP/C表现出良好的电解水性能,在电流密度为10 mA·cm^(-2)条件下,FeCoNiMoCeP/C电极电催化HER和OER所需的过电位分别为119和240 mV。在全解水研究中,FeCoNiMoCeP/C表现出优异的催化活性。在电流密度为10 mA·cm^(-2)条件下,FeCoNiMoCeP/C同时用作阴极和阳极的电解水反应所需过电位仅为1.53 V。这是由于高熵磷化物催化剂原子之间的协同作用可以提供更多的反应位点,增加反应活性和选择性。本研究可拓展高熵合金在电催化领域的潜在应用范围。

In the process of electrolyzing water to produce hydrogen,the sluggish electrocatalytic kinetics of the hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)limit the energy conversion efficiency.High-entropy materials have been considered as potential catalysts due to their unique structural features and excellent performance,which could potentially replace traditional metal oxides and precious metals for energy conversion and water electrolysis.Due to the incompatibility between different metals and non-metals,there have been few reports on the synthesis of high-entropy compounds,especially high-entropy metal phosphides.In this study,a series of carbon-based high-entropy alloy phosphide nanoparticles were synthesized using citric acid as complexing agent and ammonium dihydrogen phosphate as phosphorus source via a low-temperature Sol-Gel method with different elemental metals.In 1 mol·L^(-1)KOH solution,FeCoNiMoCeP/C exhibited good water electrolysis performance at a current density of 10 mA·cm^(-2),with overpotentials of 119 and 240 mV for the HER and OER,respectively.Similarly,in overall water splitting studies,FeCoNiMoCeP/C also showed excellent catalytic activity.When operating at a current density of 10 mA·cm^(-2),FeCoNiMoCeP/C required only 1.53 V as the combined anode and cathode voltage for electrolyzing water.This is due to the synergistic effects among the atoms of high-entropy phosphide catalysts which provide more reaction sites to increase reaction activity and selectivity.This study is expected to expand the potential applications of high-entropy alloys in the field of electrocatalysis.