Fe-Doped Ni0.85se Nanospheres Interspersed Into Carbon Nanotubes As Efficient And Stable Electrocatalyst For Overall Water Splitting

Developing and preparation of stable and efficient non-noble metal electrocatalysts is vital for overall wa-ter splitting. Herein, a series of Fe-doped Ni0.85Se (FexNi0.85-xSe, x = 0.02, 0.04, 0.05, 0.06, 0.08, 0.1, 0.15, 0.2, 0.3 and 0.4) catalysts are synthesized successfully by one-step hydrothermal method and studied as high active bifunctional catalyst for oxygen evolution reaction (OER) and hydrogen evolution reac-tion (HER) in electrolysis water splitting. The results indicates that a suitable doping can make different metal ions have a synergistic effect and improve catalytic performance. The optimal Fe0.08Ni0.77Se sam-ple shows excellent OER and HER activities. Subsequently, the introduction of carbon nanotubes (CNTs) forming Fe0.08Ni0.77Se/CNT composite further enhances the electrocatalytic activity due to high electric conductivity of carbon nanotubes network. The resulted Fe0.08Ni0.77Se/CNT3 composite exhibits smaller overpotential of 204 mV and 108 mV at a current density of 10 mA cm(-2) and a low Tafel slope of 58 mV dec(-1) and 59 mV dec(-1) than that of other composites for OER and HER, respectively. The results demon-strate that Fe0.08Ni0.77Se/CNT3 is an excellent bifunctional catalyst, providing a promising candidate for electrocatalytic water splitting. (C) 2021 Elsevier Ltd. All rights reserved.