NiFe hydroxide pillared by metaborate for efficient oxygen evolution reaction.

(1) The NiFeBO is consist of NiFe(OH) 2 layers and BO 2 − pillars. (2) The BO 2 − pillars enhance the stability of NiFe-LDH and show adsorption to hydroxyl ion due to the unsaturated electron state. (3) The addition of Fe and B elements reduces the band gap of α-Ni(OH) 2 , accelerating the catalytic process. (4) The introduced NiFeBO catalyst shows outstanding electrochemical activity for OER with low overpotential, small Tafel slope, and long-term stability. 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 BO 2 − 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 BO 2 − 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. [ABSTRACT FROM AUTHOR]