Nitrogen‐Doped NiO Nanosheet Array for Boosted Electrocatalytic N₂ Reduction

Abstract

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.

Development of Electrocatalysts for Efficient Nitrogen Reduction Reaction under Ambient Condition

“…Theoretical simulation found that the N‐doping induced the enhanced surface conductivity and upraised d‐band center, as a result of boosting *NNH stabilization and reducing reaction energy. [ 130 ] Very recently, a FE > 30% was achieved on NiO coated with N‐doped porous carbon. [ 128 ] Notably, the catalytic reaction followed a Mars‐van Krevelen mechanism according to both 15 N isotopic detection and Raman spectrum results.…”

Recent Advances in Nonprecious Metal Oxide Electrocatalysts and Photocatalysts for N2 Reduction Reaction under Ambient Condition

“…Chu and co‐workers also synthesized a N‐doped NiO (N‐NiO) nanosheets array (Figure 9c) on carbon cloth, achieving an NH 3 yield of 22.7 μg h −1 and FE of 7.3%. [ 100 ] DFT calculations disclosed that the N doping enhanced the surface conductivity, increased the d ‐band center, and promoted *NNH stabilization. Figure 9d shows that N‐NiO changed the potential‐determining step (*N 2 → *NNH) of NiO from the first hydrogenation step to the last NH 3 release step (*NH 2 → NH 3 ).…”

Exploration and Investigation of Periodic Elements for Electrocatalytic Nitrogen Reduction

“…Nitrogen doped NiO (N-NiO/CC) nanosheets were grown on carbon cloth by hydrothermal method is followed by annealing. [193] 0.1 m LiClO 4 was used as electrolyte in this case. At −0.5 V, it exhibited high faradaic efficiency (7.3%) by producing ammonia at 22.7 µg h −1 mg cat −1 rate.…”