Wahab Abdul, Iqbal Naseem, Noor Tayyaba, Ashraf Sheeraz, Raza Muhammad Arslan, Ahmad Awais, Khan Usman Ali
U.S.-Pakistan Center for Advanced Studies in Energy, National University of Sciences and Technology Islamabad 44000 Pakistan
School of Chemical and Materials Engineering, National University of Sciences and Technology Islamabad 44000 Pakistan.
RSC Adv. 2020 Jul 24;10(46):27728-27742. doi: 10.1039/d0ra04193a. eCollection 2020 Jul 21.
Oxygen electrocatalysis plays a crucial role in harnessing energy from modern renewable energy technologies like fuel cells and metal-air batteries. But high cost and stability issues of noble metal catalysts call for research on tailoring novel metal-organic framework (MOF) based architectures which can bifunctionally catalyze O reduction and evolution reactions (ORR & OER). In this work, we report a novel manganese MOF @rGO nanocomposite synthesized using a facile self-templated solvothermal method. The nanocomposite is superior to commercial Pt/C catalyst both in material resource and effectiveness in application. A more positive cathodic peak ( = 0.78 V RHE), onset ( = 1.09 V RHE) and half wave potentials ( = 0.98 V RHE) for the ORR and notable potential to achieve the threshold current density ( = 1.84 V RHE) for OER are features promising to reduce overpotentials during ORR and OER. Small Tafel slopes, methanol tolerance and acceptable short term stability augment the electrocatalytic properties of the as-prepared nanocomposite. Remarkable electrocatalytic features are attributed to the synergistic effect from the mesoporous 3D framework and transition metal-organic composition. Template directed growth, tunable porosities, novel architecture and excellent electrocatalytic performance of the manganese MOF @rGO nanocomposite make it an excellent candidate for energy applications.
氧电催化在利用现代可再生能源技术（如燃料电池和金属空气电池）获取能量方面起着至关重要的作用。但是贵金属催化剂的高成本和稳定性问题促使人们开展研究，以定制新型的基于金属有机框架（MOF）的结构，这种结构能够双功能催化氧还原和析氧反应（ORR和OER）。在这项工作中，我们报道了一种通过简便的自模板溶剂热法合成的新型锰基MOF@rGO纳米复合材料。该纳米复合材料在材料资源和应用效果方面均优于商业Pt/C催化剂。ORR具有更正的阴极峰（Epc = 0.78 V vs RHE）、起始电位（Eonset = 1.09 V vs RHE）和半波电位（E1/2 = 0.98 V vs RHE），并且在OER方面具有达到阈值电流密度的显著电位（Ej = 1.84 V vs RHE），这些特征有望降低ORR和OER过程中的过电位。较小的塔菲尔斜率、甲醇耐受性和可接受的短期稳定性增强了所制备纳米复合材料的电催化性能。显著的电催化特性归因于介孔三维框架和过渡金属有机组成的协同效应。锰基MOF@rGO纳米复合材料的模板导向生长、可调孔隙率、新颖结构和优异的电催化性能使其成为能源应用的极佳候选材料。
