Green synthesis of NiFe LDH/Ni foam at room temperature for highly efficient electrocatalytic oxygen evolution reaction

Abstract

Clean energy technologies such as water splitting and fuel cells have been intensively pursued in the last decade for their free pollution. However, there is plenty of fossil energy consumed in the preparation of the catalysts, which results in a heavy pollution. Therefore, it is much desired but challenging to fabricate high-efficiency catalysts without extra energy input. Herein, we used a facile one-pot room-temperature method to synthesize a highly efficient electrocatalyst of nickel iron layered double hydroxide grown on Ni foam (NiFe LDH/NF) for oxygen evolution reaction (OER). The formation of the NiFe LDH follows a dissolution-precipitation process, in which the acid conditions by hydrolysis of Fe 3+ combined with NO 3− could etch the NF to form Ni 2+ . Then, the obtained Ni 2+ was co-precipitated with the hydrolysed Fe 3+ to in situ generate NiFe LDH on the NF. The NiFe LDH/NF exhibits excellent OER performance with a low potential of about 1.411 V vs. reversible hydrogen electrode (RHE) at a current density of 10 mA cm −2 , a small Tafel slope of 42.3 mV dec −1 and a significantly low potential of ~1.452 V vs. RHE at 100 mA cm −2 in 1 mol L −1 KOH. Moreover, the material also keeps its original morphology and structure over 20 h. This energy-efficient strategy to synthesize NiFe LDH is highly promising for widespread application in OER catalyst industry.