Mishra Abhaya Kumar, Willoughby Joshua, Estes Shanna L, Kohler Keliann Cleary, Brinkman Kyle S
Department of Materials Science and Engineering, Clemson University Clemson SC 29634 USA
Department of Environmental Engineering and Earth Sciences, Clemson University Anderson SC 29625 USA
Nanoscale Adv. 2024 Jul 23;6(18):4672-4682. doi: 10.1039/d4na00500g. eCollection 2024 Sep 10.
Designing a highly efficient, low-cost, sustainable electrocatalyst for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) through water splitting is a current challenge for renewable energy technologies. This work presents a modified sol-gel route to prepare metal-ion(s) doped cerium oxide nanostructures as an efficient electrocatalyst for overall water splitting. Nickle (Ni) and iron (Fe) co-doping impacts the morphology in cerium oxide resulting in 5 nm nanoparticles with a mesoporous-like microstructure. The high level 20 mol% (1 : 1 ratio) of Ni + Fe bimetal-ion(s) doped CeO shows excellent HER and OER activities compared to the monodoped Fe/Ni and pristine CeO. The co-doped catalysts required a low overpotential of 104 mV and 380 mV for HER and OER, respectively, in 1 M KOH, at a current density of 10 mA cm. The Tafel slopes of 95 mV dec and 65 mV dec were measured for HER and OER with the same representative samples which demonstrated excellent stability even after continuous operation for 20 hours in the alkaline medium. The unique morphology, enhanced oxygen vacancy (O) content and the synergistic effects of dopants in CeO play essential roles in enhancing the activities of Ni + Fe doped samples.
通过水分解设计一种用于析氢反应（HER）和析氧反应（OER）的高效、低成本、可持续的电催化剂是可再生能源技术当前面临的挑战。这项工作提出了一种改进的溶胶 - 凝胶路线，以制备金属离子掺杂的氧化铈纳米结构作为用于整体水分解的高效电催化剂。镍（Ni）和铁（Fe）共掺杂影响氧化铈的形态，形成具有介孔状微观结构的5纳米纳米颗粒。与单掺杂的Fe/Ni和原始CeO相比，20摩尔％（1：1比例）的高含量Ni + Fe双金属离子掺杂的CeO表现出优异的HER和OER活性。在1 M KOH中，电流密度为10 mA cm时，共掺杂催化剂的HER和OER分别需要104 mV和380 mV的低过电位。使用相同的代表性样品对HER和OER测量的塔菲尔斜率分别为95 mV dec和65 mV dec，即使在碱性介质中连续运行20小时后也表现出优异的稳定性。CeO中独特的形态、增加的氧空位（O）含量以及掺杂剂的协同效应在提高Ni + Fe掺杂样品的活性中起着至关重要的作用。
