Jaśkaniec Sonia, Hobbs Christopher, Seral-Ascaso Andrés, Coelho João, Browne Michelle P, Tyndall Daire, Sasaki Takayoshi, Nicolosi Valeria
School of Chemistry, Trinity College Dublin, Dublin, Ireland.
CRANN&AMBER, Trinity College Dublin, Dublin, Ireland.
Sci Rep. 2018 Mar 8;8(1):4179. doi: 10.1038/s41598-018-22630-0.
This paper describes the wet-chemistry synthesis of highly crystalline hexagonal flakes of Ni-Fe layered double hydroxide (LDH) produced at temperature as low as 100 °C. The flakes with diameter in the range of 0.5-1.5 μm and the thickness between 15 and 20 nm were obtained by homogeneous precipitation method with the use of triethanolamine (TEA) and urea. By analyzing the intermediate products, it is suggested that, differently from previous reports, a thermodynamically metastable iron oxyhydroxide and Ni-TEA complex are firstly formed at room temperature. Subsequently, when the mixture is heated to 100 °C and the pH increases due to the thermal decomposition of urea, Ni and Fe are slowly released and then recombine, thus leading to formation of pure, highly-crystalline Ni-Fe LDH flakes. This material showed promising results as an electrocatalyst in oxygen evolution reaction (OER) providing an overpotential value of 0.36 V.
本文描述了在低至100°C的温度下通过湿化学合成法制备高度结晶的六方片状镍铁层状双氢氧化物（LDH）。通过使用三乙醇胺（TEA）和尿素的均匀沉淀法获得了直径在0.5-1.5μm范围内且厚度在15至20nm之间的薄片。通过分析中间产物表明，与先前的报道不同，在室温下首先形成热力学亚稳的羟基氧化铁和镍-TEA络合物。随后，当混合物加热至100°C且由于尿素的热分解导致pH值升高时，镍和铁缓慢释放然后重新结合，从而导致形成纯的、高度结晶的镍铁LDH薄片。该材料作为析氧反应（OER）中的电催化剂显示出有前景的结果，其过电位值为0.36V。
