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

摘要: 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，Ni_1.5Fe_0.5Se₂/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，Ni_1.33Fe_0.67Se₂/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，Ni_1.5Fe_0.5Se₂/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。

Abstract: 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, Ni_1.5Fe_0.5Se₂/NF shows the best catalytic activity for HER, with the corresponding overpotential of 126.3 mV at 10 mA∙cm⁻². Moreover, Ni_1.33Fe_0.67Se₂/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, Ni_1.5Fe_0.5Se₂/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.