摘要
通过在聚苯乙烯(polystyrene, PS)小球上包覆聚吡咯层(polypyrrole, PPy),利用可控热解法制备中空碳球(hollow carbon sphere, HCS),采用湿还原法将铂纳米颗粒沉积在碳球表面,记为HCS-Pt。此外,本文还以质子化石墨相氮化碳(P-g-C3N4)为前驱体,在可控热解下制备无定形碳(amorphous carbon, AC),同样采用湿还原法沉积Pt到无定形碳表面,记为AC-Pt。通过透射电子显微镜(TEM)和X射线粉末衍射仪(XRD)对Pt结构进行表征,探究不同形态的碳载体对其表面Pt纳米颗粒的生长及分布情况的影响。结合电化学催化性能测试,研究样品在碱性介质中的氧气还原反应(oxygen reduction reaction, ORR)性能。与AC相比,Pt在HCS载体表面形成了更小粒径的纳米Pt,分散更均匀。在0.1 M KOH电解质中,HCS-Pt比AC-Pt显示出更正向的氧气还原峰和半波电位、更小的塔菲尔斜率并且伏安扫描曲线的响应面积更大,表明HCS-Pt的ORR催化性能明显优于AC-Pt。
Here, polypyrrole (PPy) coatings were deposited on polystyrene (PS) nanospheres (PS@PPy), followed by controlled pyrolysis to form the hollow carbon sphere (HCS) under, then platinum nanoparticles were deposited on the surface of HCS via wet-chemistry reduction, denoted as HCS-Pt. In addition, protonated graphitic carbon nitride (P-g-C3N4) was used as the precursor to prepare amorphous carbon (AC) under controlled pyrolysis. Also, Pt was deposited on the surface of AC with the same method, the products were denoted as AC-Pt. The structures of Pt nanoparticles were characterized by the transmission electron microscopy (TEM) and X-ray powder diffractometer (XRD), and the effects of carbon supports with different types on the growth and distribution of Pt nanoparticles were investigated. The oxygen reduction reaction (ORR) performances of the samples were evaluated by electrochemical analysis in alkaline medium. Compared with AC-Pt, Pt nanoparticles anchored on HCS presented a smaller size and a homogeneous dispersed state. At 0.1 M KOH electrolyte, HCS-Pt showed more positive oxygen reduction peak and half-wave potential, a smaller Tafel slope, and a larger response area of the voltammetry sweep curve than AC-Pt. The results show that the ORR performance of HCS-Pt is better than that of AC-Pt in alkaline media.
出处
《物理化学进展》
2023年第3期161-170,共10页
Journal of Advances in Physical Chemistry
