NiFe hydroxide pillared by metaborate for efficient oxygen evolution reaction

Water-splitting by electrolysis is one of the most important approaches to produce hydrogen as renewable clean energy with superior advantages of high-purity and good operability. But the key issue limiting the large-scale application is that it demands a much higher overpotential than the theoretical oxygen evolution potential. Herein, we report an efficient electrochemical catalyst of NiFeBO synthesized via a facile one-step process, presenting remarkable catalytic activity and long-term stability. In this work, we discussed the effects of the doping of Fe and the insertion of BO₂⁻ in the as-synthesized NiFeBO. According to the experimental results, NiFeBO shows a very low overpotential of 256 mV and a Tafel slope of 53 mV dec⁻¹ with remarkable stability over 60 h of chronopotentiometry test. The inserted anion of BO₂⁻ can adsorb OH⁻ in electrolyte around the catalyst to increase the concentration of OH⁻ around the active sites, thereby improving the effectivity of oxygen evolution reaction. In addition, diffused micro-crystalline with different lattice formed during the oxidation of the as-synthesized catalyst, providing more active sites than the pristine amorphous.