Yi Xuerui, He Xiaobo, Yin Fengxiang, Chen Biaohua, Li Guoru, Yin Huaqiang
College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, PR China.
Dalton Trans. 2020 May 28;49(20):6764-6775. doi: 10.1039/c9dt04755g. Epub 2020 May 6.
Developing earth-abundant highly efficient catalysts for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is indispensable for the widespread implementation of electrochemical water splitting to store renewable energy. Herein, amorphous bimetallic selenide (Ni-Fe-Se) hollow nanospheres electrodeposited on nickel foam (Ni-Fe-Se/NF) are developed as a bifunctional catalyst for the HER and OER. The HER and OER bifunctional activity of Ni-Fe-Se/NF outperforms those of monometallic Ni-Se/NF and Fe-Se/NF owing to the synergy of Ni and Fe in Ni-Fe-Se/NF. Moreover, the amorphous hollow spherical morphology of Ni-Fe-Se/NF increases the active site density and facilitates the mass transfer of electrolytes and H/O products. Ni-Fe-Se/NF drives a current density of 10 mA cm with an overpotential of ∼85 mV for the HER and 100 mA cm with an overpotential of ∼222 mV for the OER. As the HER and OER bifunctional catalyst, Ni-Fe-Se/NF can split alkaline water with total voltages of ∼1.52 V and ∼1.66 V at 10 mA cm and 100 mA cm, respectively, and remain stable over 50 hours of operation in 1 M KOH.
开发用于析氧反应（OER）和析氢反应（HER）的储量丰富且高效的催化剂，对于电化学水分解广泛应用以存储可再生能源而言必不可少。在此，电沉积在泡沫镍上的非晶态双金属硒化物（Ni-Fe-Se）空心纳米球（Ni-Fe-Se/NF）被开发为用于HER和OER的双功能催化剂。由于Ni-Fe-Se/NF中Ni和Fe的协同作用，其HER和OER双功能活性优于单金属Ni-Se/NF和Fe-Se/NF。此外，Ni-Fe-Se/NF的非晶态空心球形形态增加了活性位点密度，并促进了电解质和H/O产物的传质。Ni-Fe-Se/NF在HER时驱动10 mA cm的电流密度，过电位约为85 mV，在OER时驱动100 mA cm的电流密度，过电位约为222 mV。作为HER和OER双功能催化剂，Ni-Fe-Se/NF分别在10 mA cm和100 mA cm时能以约1.52 V和约1.66 V的总电压分解碱性水，并在1 M KOH中运行50小时以上保持稳定。
