Interfacial Engineering of NiCo Nanocones to Promote NiOOH Formation via Enhanced Dehydrogenation for Efficient Urea Electrooxidation

Abstract Electrochemical urea oxidation reaction (UOR) is widely recognized as a promising approach for achieving energy‐efficient hydrogen production and wastewater purification simultaneously. However, the formation of NiOOH reactive species, coupled with efficient CO 2 desorption, remains a challenge for achieving superior UOR performance when employing Ni‐based electrocatalysts. Herein, Ni x Co 1‐x nanocone catalysts are fabricated to enhance the UOR performances. The interfacial modification with Co atoms induced more α‐Ni(OH) 2 phase formation and electron migration from Ni to Co, thereby notably enhancing the dehydrogenation to generate NiOOH with enriched γ‐NiOOH phase, as demonstrated by in situ characterization and computational studies. In addition, the local electric field enhancement and the optimized in‐plane/out‐of‐plane capillary forces derived from the nanocone structure significantly facilitated CO 2 desorption and reaction kinetics. Accordingly, the optimal Ni 0.9 Co 0.1 ‐NC electrode exhibited an ultralow onset potential of 1.30 V versus RHE and a high current density of 332 mA cm −2 at 1.40 V versus RHE, surmounting Ni‐NC and Co‐NC by 5.5 and 17 times, respectively. It also demonstrated an excellent durability (90 h), highlighting strong practical potential. This work provides a facile approach for fabricating high‐performance Ni‐based UOR catalysts and offers insights into interfacial regulation mechanisms of Co doping.