Oubraham Anisoara, Ion-Ebrasu Daniela, Vasut Felicia, Soare Amalia, Sorlei Ioan-Sorin, Marinoiu Adriana
National Institute for Cryogenics and Isotopic Technologies ICSI-Rm. Valcea, ICSI Energy, Uzinei Str. no. 4, 240050 Ramnicu Valcea, Romania.
Materials (Basel). 2023 Feb 24;16(5):1897. doi: 10.3390/ma16051897.
This paper presents the preparation of platinum on a reduced graphene oxide matrix (PtrGO) using the microwave-assisted method with three different pH solutions. The platinum concentration determined by energy-dispersive X-ray analysis (EDX) was 4.32 (weight%), 2.16 (weight %) and 5.70 (weight%), corresponding to pH 3.3, 11.7 and 7.2, respectively. Pt functionalization of reduced graphene oxide (rGO) decreased the rGO specific surface, as shown by Brunauer, Emmett and Teller (BET) analysis. An XRD spectrum of platinum-decorated reduced graphene oxide (rGO) showed the presence of the associated phases of rGO and centered cubic platinum peaks. An oxygen reduction reaction (ORR) electrochemical characterization performed using the rotating disk electrode (RDE) method showed that in PtGO1 synthetized in an acidic environment, with 4.32 Pt (weight%) determined by EDX, platinum is much more dispersed, which explains its better electrochemical oxygen reduction reaction performance. Koutecky-Levich (K-L) plots calculated at different potentials prove a good linear relationship. Electron transfer numbers () determined from the K-L plots are between 3.1 and 3.8, which confirms that the ORR for all the samples can be regarded as first-order reaction kinetics of O concentration formed on the Pt surface during ORR.
本文介绍了采用微波辅助法在三种不同pH值溶液中制备还原氧化石墨烯负载铂(PtrGO)的过程。通过能量色散X射线分析(EDX)测定的铂浓度分别为4.32(重量%)、2.16(重量%)和5.70(重量%),对应pH值分别为3.3、11.7和7.2。如布鲁诺尔、埃米特和泰勒(BET)分析所示,还原氧化石墨烯(rGO)的铂功能化降低了rGO的比表面积。铂修饰还原氧化石墨烯(rGO)的XRD光谱显示存在rGO的相关相和立方晶系铂的中心峰。使用旋转圆盘电极(RDE)方法进行的氧还原反应(ORR)电化学表征表明,在酸性环境中合成的PtGO1中,通过EDX测定的铂含量为4.32(重量%),铂的分散性更好,这解释了其更好的电化学氧还原反应性能。在不同电位下计算的科泰克-列维奇(K-L)图证明了良好的线性关系。从K-L图确定的电子转移数()在3.1至3.8之间,这证实了所有样品的ORR可视为ORR过程中在铂表面形成的O浓度的一级反应动力学。