镍铁双金属硒化物的制备及其电催化性能

Preparation and Electrocatalytic Performance of Nickel-Iron Bimetallic Selenide

本文采用两步水热法,以镍铁层状双金属氢氧化物(NiFe LDH)为前驱体,选择二氧化硒作为硒化反应的硒源,无害无污染的柠檬酸钠作为硒化反应的还原剂,在泡沫镍(NF)上制备了具有微观片状结构的不同镍铁投料比的镍铁硒化物(即NiFeSe2/NF)。在1.0 M KOH中,NiFeSe2/NF具有优良的析氢(HER)和析氧(OER)性能,可用作双功能电催化剂。在所得的不同镍铁比样品中,Ni1.5Fe0.5Se2/NF具有最佳的HER催化活性,在10 mA∙cm−2下对应过电位大小为126.3 mV。此外,Ni1.33Fe0.67Se2/NF是OER催化性能最优越的样品,在50 mA∙cm−2下对应过电位为295 mV,Tafel斜率低至67.4 mV∙dec−1。此外,Ni1.5Fe0.5Se2/NF的全解水性能优良,在10 mA∙cm−2下,对应电压低至1.53 V。本文为合成具有双功能电催化活性的硒化物提供了一种更安全、简便的新途径。

In this paper, a two-step hy-drothermal method was used to prepare nickel-iron selenide (NiFeSe2/NF) with different nick-el-iron feed ratios on Nickel Foam (NF), using Nickel-iron Layered Double Hydroxide (NiFe LDH) as the precursor, SeO2 as the selenium source and harmless and non-polluting sodium citrate as the reducing agent of the selenization reaction. NiFeSe2/NF has excellent electrocatalytic performance for both Hydrogen Evolution Reaction (HER) and Oxygen Evolution Reaction (OER) in 1.0 M KOH electrolyte, and can be used as a bifunctional electrocatalyst. Among samples with different nick-el-iron ratios, Ni1.5Fe0.5Se2/NF shows the best catalytic activity for HER, with the corresponding overpotential of 126.3 mV at 10 mA∙cm−2. Moreover, Ni1.33Fe0.67Se2/NF exhibits the most remarkable catalytic performance for OER, corresponding to the overpotential of 295 mV at 50 mA∙cm−2, and a Tafel slope as low as 67.4 mV∙dec−1. In addition, Ni1.5Fe0.5Se2/NF has optimal performance for overall water splitting, and the corresponding voltage is as low as 1.53 V at 10 mA∙cm−2. This paper pro-vides a safer and simple method for synthesizing bimetallic selenides with bi-functional electrocat-alytic activity.