Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), School of Materials Science and Engineering, Smart Sensing Interdisciplinary Science Center, Nankai University, Tianjin, 300350, China.
Small. 2023 Jul;19(27):e2300194. doi: 10.1002/smll.202300194. Epub 2023 Mar 25.
Versatile electrocatalysis at higher current densities for natural seawater splitting to produce hydrogen demands active and robust catalysts to overcome the severe chloride corrosion, competing chlorine evolution, and catalyst poisoning. Hereto, the core-shell-structured heterostructures composed of amorphous NiFe hydroxide layer capped Ni S nanopyramids which are directly grown on nickel foam skeleton (NiS@LDH/NF) are rationally prepared to regulate cooperatively electronic structure and mass transport for boosting oxygen evolution reaction (OER) performance at larger current densities. The prepared NiS@LDH/NF delivers the anodic current density of 1000 mA cm at the overpotential of 341 mV in 1.0 m KOH seawater. The feasible surface reconstruction of Ni S -FeNi LDH interfaces improves the chemical stability and corrosion resistance, ensuring the robust electrocatalytic activity in seawater electrolytes for continuous and stable oxygen evolution without any hypochlorite production. Meanwhile, the designed Ni S nanopyramids coated with FeNi P layer (NiS@FeNiP/NF) still exhibit the improved hydrogen evolution reaction (HER) activity in 1.0 m KOH seawater. Furthermore, the NiS@FeNiP/NF||NiS@LDH/NF pair requires cell voltage of 1.636 V to attain 100 mA cm with a 100% Faradaic efficiency, exhibiting tremendous potential for hydrogen production from seawater.
在较高电流密度下进行自然海水分解以生产氢气需要活性和稳定的催化剂来克服严重的氯化物腐蚀、竞争的氯析出和催化剂中毒。为此，合理设计了由无定形 NiFe 氢氧化物层覆盖的 Ni S 纳米金字塔组成的核壳结构异质结构，这些纳米金字塔直接生长在镍泡沫骨架上（NiS@LDH/NF），以协同调节电子结构和质量传输，从而在更大的电流密度下提升氧析出反应（OER）性能。所制备的 NiS@LDH/NF 在 1.0 m KOH 海水中的过电势为 341 mV 时，提供了 1000 mA cm 的阳极电流密度。Ni S -FeNi LDH 界面的可行表面重构提高了化学稳定性和耐腐蚀性，确保了在海水电解质中稳定的氧气析出，而不会产生次氯酸盐。同时，设计的涂覆有 FeNi P 层的 Ni S 纳米金字塔（NiS@FeNiP/NF）在 1.0 m KOH 海水中仍表现出改进的析氢反应（HER）活性。此外，NiS@FeNiP/NF||NiS@LDH/NF 对在 1.0 m KOH 海水中需要 1.636 V 的电池电压即可达到 100 mA cm，且具有 100%的法拉第效率，显示出从海水中生产氢气的巨大潜力。
