Bifunctional nanoporous Ni-Co-Se electrocatalyst with superaerophobic surface for the water and hydrazine oxidation
The sluggish kinetics of oxygen evolution reaction (OER) has severely hindered the energetic convenience of water splitting. Thus, developing highly efficient catalyst for OER and replacing OER with hydrazine oxidation (HzOR) is an effective strategy for water electrolysis to achieve sustainable hydrogen production. Herein, bifuncitional nanosheet arrays Ni0.6Co0.4Se with porous structure were fabricated on Ni foam (NF) by bubble dynamic template method during electrodeposition. Compared with CoSe2 and NiSe2, Ni0.6Co0.4Se exhibits excellent electrocatalytic performance for both OER and HzOR. A low overpotential of only 249 mV is required to drive 10 mA cm-2, and a retention rate of nearly 100 % after 24 h at 10 mA cm-2 is observed for Ni0.6Co0.4Se towards OER. By substituting OER by HzOR, an extremely high current density of 300 mA cm-2 at 0.4 V vs. RHE and a retention rate of 86.8 % at 200 mA cm-2 after 12 h can be achieved. Interestingly, the mechanism reason for the enhanced catalytic ability of Ni0.6Co0.4Se was studied, which is associated with the synergistic effects of Ni and Co, large ECSA, high electrical conductivity and most importantly, the superaerophobic nature induced by the porous structure of Ni0.6Co0.4Se. The non-noble metal bifunctional electrocatalyst demonstrates a promising potential for the application of both OER and HzOR.