Functional Material and Energy Devices Laboratory, Department of Physics and Nanotechnology, SRM Institute of Science and Technology, Kattankulathur, Potheri, Chengalpattu, 603 203, India.
Nanotechnology Research Centre (NRC), Faculty of Engineering and Technology, SRM Institute of Science and Technology, Kattankulathur, Potheri, Chengalpattu, 603 203, India; Department of Physics, Bannari Amman Institute of Technology, Sathyamangalam, Tamil nadu, India; Department of Physiology, Saveetha Dental college and hospitals, Saveetha Institute of Medical and Technical sciences, Saveetha University, chennai - 600077, Tamil nadu, India.
Chemosphere. 2024 Jan;346:140574. doi: 10.1016/j.chemosphere.2023.140574. Epub 2023 Nov 3.
Water splitting provides an environmental-friendly and sustainable approach for generating hydrogen fuel. The inherent energetic barrier in two-core half reactions such as the Hydrogen Evolution Reaction (HER) and Oxygen Evolution Reaction (OER) leads to undesired increased overpotential and constrained reaction kinetics. These challenges pose significant challenges that demand innovative solutions to overcome. One of the efficient ways to address this issue is tailoring the morphology and crystal structure of metal-organic frameworks (MOF). Nickel Zeolite Imidazolate Framework (Ni-ZIF) is a popular MOF and it can be tailored using facile chemical methods to unleash a remarkable bifunctional electro/photo catalyst. This innovative solution holds the capability to address prevailing obstacles such as inadequate electrical conductivity and limited access to active metal centers due to the influence of organic ligands. Thereby, applying boronization to the Ni-ZIF under different duration, one can induce blooming of nanobuds under room temperature and modify oxygen vacancies in order to achieve higher reaction kinetics in electro/photo catalysis. It can be evidenced by the 24-h boronized Ni-ZIF (BNZ), exhibiting lower overpotentials as electrocatalyst (OER-396 mV & HER-174 mV @ 20 mA/cm) in 1 M KOH electrolyte and augmented gas evolution rates when employed as a photocatalyst (Hydrogen-14.37 μmol gmin & Oxygen-7.40 μmol gmin). The 24-h boronization is identified as the optimum stage of crystalline to amorphous transformation which provided crystalline/amorphous boundaries as portrayed by X-Ray diffraction (XRD) and High Resolution-Transmission Electron Microscopy (HR-TEM) analysis. The flower-like transformation of 24-BNZ, characterized by crystalline-amorphous boundaries initiates with partial disruption of Ni-N bonds and formation of Ni-B bonds as evident from X-ray Photoelectron Spectroscopy (XPS). Further, the 24-h BNZ exhibit bifunctional catalytic activities with pre-longed stability. Overall, this work presents a comprehensive study of the electrocatalytic and photocatalytic water splitting properties of the tailored Ni-ZIF material.
水分解为生成氢气燃料提供了一种环保且可持续的方法。两个核心半反应（如析氢反应 (HER) 和析氧反应 (OER)）的固有能量障碍导致不期望的过电势增加和受限的反应动力学。这些挑战带来了重大挑战，需要创新的解决方案来克服。解决这个问题的一种有效方法是调整金属有机骨架 (MOF) 的形态和晶体结构。镍沸石咪唑骨架 (Ni-ZIF) 是一种流行的 MOF，可以通过简便的化学方法进行调整，以释放出出色的双功能电/光催化剂。这种创新解决方案有能力解决由于有机配体的影响而导致的电导率不足和对活性金属中心的有限访问等普遍障碍。因此，在不同时间下对 Ni-ZIF 进行硼化处理，可以在室温下诱导纳米芽的绽放，并修饰氧空位，从而在电/光催化中实现更高的反应动力学。这可以通过 24 小时硼化 Ni-ZIF (BNZ) 得到证明，其在 1 M KOH 电解质中作为电催化剂（OER-396 mV 和 HER-174 mV @ 20 mA/cm）的过电势较低，并且作为光催化剂时的气体释放速率增加（氢气-14.37 μmol gmin 和氧气-7.40 μmol gmin）。24 小时硼化被确定为晶态到非晶态转变的最佳阶段，这提供了晶态/非晶态边界，如 X 射线衍射 (XRD) 和高分辨率透射电子显微镜 (HR-TEM) 分析所示。24-BNZ 的花状转变，具有晶态/非晶态边界，是从 Ni-N 键的部分破坏和 Ni-B 键的形成开始的，这可以从 X 射线光电子能谱 (XPS) 中看出。此外，24 小时 BNZ 表现出双功能催化活性和延长的稳定性。总的来说，这项工作全面研究了定制 Ni-ZIF 材料的电催化和光催化水分解性能。
