Nitrogen‐Doped NiO Nanosheet Array for Boosted Electrocatalytic N2 Reduction

• Published in: ChemCatChem 2019-09, Vol.11 (18), p.4529-4536
• Main Authors: Wang, Xiao‐hu, Wang, Jing, Li, Yu‐biao, Chu, Ke
• Format: Article
• Language: English
• Subjects: Ammonia; Arrays; Chemical reduction; Cloth; Density functional theory; Doping; Electrocatalysts; Electrochemical NH3 synthesis; N2 reduction reaction; Nanosheets; Nickel oxides; NiO Nanosheet Array; Nitrogen; Nitrogen doping; Nitrogenation; Transition metals
• ISSN: 1867-3880; 1867-3899
• DOI: 10.1002/cctc.201901075

Electrocatalytic N2 reduction reaction (NRR) provides a sustainable approach for ambient N2 fixation. Non‐noble transition metal‐based electrocatalysts (TMEs) are emerging as the most promising NRR catalysts, but commonly exhibited limited NRR activity. Heteroatom doping is an effective method to improve the electrocatalytic activity of TMEs by finely modulating the electronic structures. Herein, as a proof‐of‐concept, nitrogen‐doped NiO nanosheet array on carbon cloth (N‐NiO/CC) was investigated as model heteroatom‐doped TMEs for NRR. The N‐NiO/CC exhibited the considerably enhanced NRR performance with a NH3 yield of 22.7 μg h−1 mg−1 and an FE of 7.3 % in 0.1 M LiClO4 at −0.5 V (vs. RHE), far superior to those of undoped counterpart. Density functional theory (DFT) calculations revealed that the N‐doping could induce the enhanced surface conductivity and upraised d‐band center, leading to promoted *NNH stabilization, reduced reaction energy barrier and thus improved NRR performance. It's dope! A nitrogen‐doped NiO nanosheet array on carbon cloth (N‐NiO/CC) exhibited enhanced NRR performance with a NH3 yield of 22.7 μg h−1 mg−1 and an FE of 7.3 % in 0.1 M LiClO4 at −0.5 V (vs. RHE), far superior to those of undoped counterparts (NiO/CC). DFT calculations revealed that the N‐doping could induce enhanced surface conductivity and an upraised d‐band center, leading to promoted *NNH stabilization, a reduced reaction energy barrier, and thus improved NRR performance.