Huang Huawei, Xu Liangliang, Zuo Shouwei, Ren Yuanfu, Song Lu, Zou Chen, Wang Xingkun, Martínez Javier Ruiz, Huang Kuo-Wei, Zhang Huabin
Center for Renewable Energy and Storage Technologies (CREST), Physical Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia.
KAUST Catalysis Center (KCC), King Abdullah University of Science and Technolog, Thuwal, 23955-6900, Saudi Arabia.
Angew Chem Int Ed Engl. 2025 Jan 10;64(2):e202414647. doi: 10.1002/anie.202414647. Epub 2024 Dec 4.
As a half-reaction in anion exchange membrane water electrolysis (AEMWE) technology, the hydrogen evolution reaction (HER) at the cathode is severely hindered by the sluggish reaction kinetics involved in additional water dissociation step, which results in large overpotentials and low energy conversion efficiency. Here, we develop a nano-heterostructure composed of ultra-thin WN shells over NiN nanoparticles (NiN@WN) as efficient catalysts, in which built-in interfacial electric field (BIEF) is created owing to the distinct lattice arrangements and work functions of biphasic metal nitrides. The BIEF facilitates the electron localization around the interface and enables high valence W and more exposed binding sites in the surface WN shell for accelerating the water dissociation step, ultimately leading to a remarkable reduction in the energy barriers of RDS from 1.40 eV to 0.26 eV. Theoretical calculations and operando X-ray absorption spectroscopy analysis results demonstrated that surface WN serves as the active species for HER. Moreover, the ultra-thin shell characteristics enable the optimized WN with enhanced intrinsic catalytic activity to be fully exposed as active sites. Consequently, the NiN@WN exhibits exceptional performance in alkaline HER (60 mV@10 mA cm) and remarkable long-term stability (500 mA cm for 100 hours). When employed as the cathode in the AEMWE device, the synthesized NiN@WN demonstrates stable performance for 90 hours at a current density of 1 A cm.
作为阴离子交换膜水电解（AEMWE）技术中的一个半反应，阴极析氢反应（HER）因额外的水离解步骤涉及缓慢的反应动力学而受到严重阻碍，这导致了较大的过电位和较低的能量转换效率。在此，我们开发了一种由NiN纳米颗粒上的超薄WN壳组成的纳米异质结构（NiN@WN）作为高效催化剂，其中由于双相金属氮化物不同的晶格排列和功函数而产生了内建界面电场（BIEF）。BIEF促进了界面周围的电子定位，并使高价态的W以及表面WN壳中更多暴露的结合位点能够加速水离解步骤，最终使速率决定步骤（RDS）的能垒从1.40 eV显著降低至0.26 eV。理论计算和原位X射线吸收光谱分析结果表明，表面WN是HER的活性物种。此外，超薄壳层特性使具有增强本征催化活性的优化WN能够作为活性位点充分暴露。因此，NiN@WN在碱性HER中表现出优异的性能（在10 mA cm时过电位为60 mV）和显著的长期稳定性（在500 mA cm下持续100小时）。当用作AEMWE装置的阴极时，合成的NiN@WN在1 A cm的电流密度下表现出90小时的稳定性能。
