Wang Ze, Song Xinyu, Liu Yue, Sun Zhiwang, Zhang Xin, Wang Yuanhao, Wang Shifeng
Key Laboratory of Plateau Oxygen and Living Environment of Xizang Autonomous Region, College of Science, Xizang University, Lhasa 850000, China.
Hoffmann Institute of Advanced Materials, Shenzhen Polytechnic University, Shenzhen 518000, China.
Nanomaterials (Basel). 2025 Aug 14;15(16):1255. doi: 10.3390/nano15161255.
Electrochemical water splitting for hydrogen production is considered a key pathway for achieving sustainable energy conversion. However, the sluggish reaction kinetics of the oxygen evolution reaction (OER) and high overpotentials severely hinder the large-scale application of water electrolysis technology. Nickel-iron layered double hydroxide (NiFe-LDH) has gained attention as a promising non-precious metal OER catalyst due to its abundant active sites and good intrinsic activity. However, its relatively low conductivity and charge transfer efficiency limit the improvement of catalytic performance. Therefore, this study used a simple hydrothermal method to generate a NiFe-LDH/CsWO heterojunction composite catalyst, relying on the excellent electronic conductivity of CsWO to improve overall charge transfer efficiency. According to electrochemical testing results, the modified NiFe-LDH/CsWO-20 mg achieved a low overpotential of 349 mV at a current density of 10 mA cm, a Tafel slope of 67.0 mV dec, and a charge transfer resistance of 65.1 Ω, which represent decreases of 39 mV, 23.1%, and 40%, respectively, compared to pure NiFe-LDH. The key to performance improvement lies in the tightly bonded heterojunction interface between CsWO and NiFe-LDH. X-ray photoelectron spectroscopy (XPS) shows a distinct interfacial charge transfer phenomenon, with a notable negative shift of the W4f peak (0.85 eV), indicating the directional transfer of electrons from CsWO to NiFe-LDH. Under the influence of the built-in electric field within the heterojunction, this interfacial charge redistribution improved the electronic structure of NiFe-LDH, increased the proportion of high-valent metal ions, and significantly enhanced the OER reaction kinetics. This study provides new insights for the preparation of efficient heterojunction electrocatalysts.
电化学水分解制氢被认为是实现可持续能源转换的关键途径。然而，析氧反应（OER）缓慢的反应动力学和高过电位严重阻碍了水电解技术的大规模应用。镍铁层状双氢氧化物（NiFe-LDH）因其丰富的活性位点和良好的本征活性而作为一种有前景的非贵金属OER催化剂受到关注。然而，其相对较低的电导率和电荷转移效率限制了催化性能的提高。因此，本研究采用简单的水热法制备了NiFe-LDH/CsWO异质结复合催化剂，依靠CsWO优异的电子导电性提高整体电荷转移效率。根据电化学测试结果，改性后的NiFe-LDH/CsWO-20 mg在电流密度为10 mA cm时实现了349 mV的低过电位，塔菲尔斜率为67.0 mV dec，电荷转移电阻为65.1 Ω，与纯NiFe-LDH相比，分别降低了39 mV、23.1%和40%。性能提升的关键在于CsWO与NiFe-LDH之间紧密结合的异质结界面。X射线光电子能谱（XPS）显示出明显的界面电荷转移现象，W4f峰有显著的负移（0.85 eV），表明电子从CsWO向NiFe-LDH的定向转移。在异质结内建电场的影响下，这种界面电荷重新分布改善了NiFe-LDH的电子结构，增加了高价金属离子的比例，并显著增强了OER反应动力学。本研究为高效异质结电催化剂的制备提供了新的见解。
