Humayun Amir, Manivelan Nandapriya, Prabakar Kandasamy
Advanced Sustainable Energy Laboratory, Department of Electrical and Electronics Engineering, Pusan National University, 2 Busandaehak-ro 63beon-gil, Geumjeong-Gu, Busan 46241, Republic of Korea.
Nanomaterials (Basel). 2024 Sep 18;14(18):1515. doi: 10.3390/nano14181515.
This study aims to explore the n-FeO and p-α-FeO semiconductor nanoparticles in hydrogen (HER) and oxygen (OER) evolution reactions and a combined full cell electrocatalyst system to electrolyze the water. We have observed a distinct electrocatalytic performance for both HER and OER by tuning the interplay between iron oxidation states Fe and Fe and utilizing phase-transformed iron oxide nanoparticles (NPs). The Fe rich n-FeO NPs exhibited superior HER performance compared to p-α-FeO and Fe(OH) NPs, which is attributed to the enhancement in n-type semiconducting nature under HER potential, facilitating the electron transfer for the reduction in H ions. In contrast, p-α-FeO NPs demonstrated excellent OER activity. An H-cell constructed using n-FeO||p-α-FeO NPs as cathode and anode achieved a cell voltage of 1.87 V at a current density of 50 mA/cm. The cell exhibited remarkable stability after 30 h of activation and maintained the high current density of 100 mA/cm for 80 h with a negligible increase in cell voltage. This work highlights the semiconducting properties of n-FeO and p-α-FeO for the electrochemical water splitting system using the band bending phenomenon under the applied potential.
本研究旨在探索n-FeO和p-α-FeO半导体纳米颗粒在析氢反应（HER）和析氧反应（OER）中的性能，以及一种用于电解水的组合式全电池电催化剂体系。通过调节铁氧化态Fe²⁺和Fe³⁺之间的相互作用，并利用相转变的氧化铁纳米颗粒（NPs），我们观察到了HER和OER明显的电催化性能。与p-α-FeO和Fe(OH) NPs相比，富Fe²⁺的n-FeO NPs表现出优异的HER性能，这归因于在HER电位下n型半导体性质的增强，促进了H⁺离子还原的电子转移。相比之下，p-α-FeO NPs表现出优异的OER活性。以n-FeO||p-α-FeO NPs作为阴极和阳极构建的H型电池在电流密度为50 mA/cm²时实现了1.87 V的电池电压。该电池在活化30 h后表现出显著的稳定性，并在80 h内保持100 mA/cm²的高电流密度，电池电压的增加可忽略不计。这项工作突出了n-FeO和p-α-FeO在施加电位下利用能带弯曲现象的电化学水分解系统中的半导体性质。
