生物质衍生炭负载金属催化剂的制备及析氧性能研究

Synthesis of biomass-derived carbon sheets decorated with metal nanoparticles and their catalytic performance in the oxygen evolution reaction

本文以吸附了金属离子(Ni、Fe离子)的明胶为碳源,采用高温炭化的方法,制备了明胶衍生的富氮炭负载NiFe合金的功能化复合物(NiFe-NC)。采用X射线衍射、扫描电镜、透射电镜、热重分析、电化学线性扫描等表征手段对NiFe-NC的形貌、结构和电催化析氧性能进行表征和研究。结果表明,金属纳米颗粒均匀负载在炭片的表面,暴露出了更多的活性位点,从而改善和强化了电化学反应动力学过程,提高了其作为析氧反应催化剂的催化性能和稳定性。在10 mAcm^(-2)电流密度下,过电势仅为366 mV,Tafel斜率为46.6 mV dec^(-1),并在5 mAcm^(-2)的电流密度下能够稳定工作25 h以上。

Biomass-derived carbons decorated with ultrafine metal nanoparticles were prepared by the carbonization of gelatin that had absorbed Ni and/or Fe ions.The morphology and structure of the samples were characterized by XRD,SEM,TEM,and their catalytic performance for the oxygen evolution reaction was evaluated by linear sweep voltammetry,electrochemical impedance spectroscopy and the Tafel polarization test.Results indicate that the metal nanoparticles are uniformly loaded on the carbon sheets.The FeNi alloy/carbon(FeNi/C)nanocomposite has the highest current density of10mA cm2at the lowest overpotential of366mV,and features the smallest Tafel slope of46.6mV dec1and the lowest charge transfer resistance of13.76ohm.Moreover,the FeNi/C nanocomposite also exhibits a long term stability and is able to operate at5mA cm2for25h.The combination of conductive carbon sheets,uniformly loaded FeNi nanoparticles and abundant pores is responsible for the increased catalytic activity and fast reaction kinetics of the FeNi/C nanocomposite for the oxygen evolution reaction.