Modibane Kwena Desmond, Waleng Ngwako Joseas, Ramohlola Kabelo Edmond, Maponya Thabiso Carol, Monama Gobeng Release, Makgopa Katlego, Hato Mpitloane Joseph
Nanotechnology Research Lab, Department of Chemistry, School of Physical and Mineral Sciences, University of Limpopo (Turfloop), Sovenga 0727, Polokwane, South Africa.
Department of Chemistry, Faculty of Science, Tshwane University of Technology (Acardia Campus), Pretoria 0001, South Africa.
Polymers (Basel). 2020 Jul 16;12(7):1581. doi: 10.3390/polym12071581.
A novel composite of poly(3-aminobenzoic acid) (PABA) and a cobalt zeolitic benzimidazolate framework (CoZIF) has been studied for the production of hydrogen through the hydrogen evolution reaction (HER). The structural characteristics and successful synthesis of PABA, CoZIF and the PABA/CoZIF composite were confirmed and investigated using different techniques. Probing-ray diffraction for phase analysis revealed that the composite showed a decrease and shift in peak intensities, confirming the incorporation of CoZIF on the PABA backbone via in situ polymerization, with an improvement in the crystalline phase of the polymer. The thermal stability of PABA was enhanced upon composite formation. Both scanning electron microscopy and transmission electron microscopy showed that the composite had a rough surface, owing to an interaction between the CoZIF and the external surface of the PABA. The electrochemical hydrogen evolution reaction (HER) performance of the synthesized samples was evaluated using cyclic voltammetry and Tafel analysis. The composite possessed a Tafel slope value of 156 mV/dec and an of 0.38, suggesting that the Volmer reaction coupled with either the Heyrovsky or Tafel reaction as the rate determining step. The fabricated composite showed high thermal stability and excellent tolerance as well as high electroactivity towards the HER, showing it to be a promising non-noble electrocatalyst to replace Pt-based catalysts for hydrogen generation.
一种由聚（3-氨基苯甲酸）（PABA）和钴沸石苯并咪唑骨架（CoZIF）组成的新型复合材料已被研究用于通过析氢反应（HER）制氢。使用不同技术对PABA、CoZIF和PABA/CoZIF复合材料的结构特征和成功合成进行了确认和研究。用于相分析的X射线衍射表明，复合材料的峰强度降低且发生了偏移，这证实了通过原位聚合将CoZIF掺入PABA主链中，同时聚合物的晶相有所改善。形成复合材料后，PABA的热稳定性增强。扫描电子显微镜和透射电子显微镜均显示，由于CoZIF与PABA外表面之间的相互作用，复合材料表面粗糙。使用循环伏安法和塔菲尔分析对合成样品的电化学析氢反应（HER）性能进行了评估。该复合材料的塔菲尔斜率值为156 mV/dec，η值为0.38，这表明Volmer反应与Heyrovsky反应或Tafel反应耦合作为速率决定步骤。制备的复合材料表现出高热稳定性、优异的耐受性以及对HER的高电活性，表明它是一种有前途的非贵金属电催化剂，可替代用于制氢的铂基催化剂。
