- 學位論文
利用無電鍍法製備鈷鎳磷/石墨烯奈米複合材料及其催化產氫之研究
Fabrication of Co-Ni-P/Graphene Nanocomposite Materials by Electroless Plating and Their Catalytic Characteristics on Hydrogen Generation
摘要
本研究中首先使用天然石墨以修改Hummers法完成石墨烯氧化物(簡稱GO)的製備，再以乙二醇還原成石墨烯，最後再用無電鍍法在石墨烯上析鍍鈷鎳磷奈米顆粒形成鈷鎳磷/石墨烯奈米複合材料，探討鈷鎳磷/石墨烯的性質和產氫效果。 無電鍍鈷-鎳之參數包括鍍浴pH值、鍍液溫度、析鍍時間及鍍液金屬塩比，本實驗改變不同的金屬塩比[Co(Co+Ni)]分別為0.1、0.3、0.5、0.7、0.9。實驗結果發現當pH為9、溫度70℃、析鍍時間1分鐘、金屬塩比[Co(Co+Ni)]為0.9時，鈷鎳磷奈米顆粒平均粒徑為8.76nm，且均勻的分佈在石墨烯上，由TEM和EDS分析結果發現隨著金屬塩比[Co(Co+Ni)]的增加，無電鍍鈷鎳的析出物會由鎳的相變成鈷的相，且鈷含量會隨著增加，最高可達48.9 at%，而鎳含量會隨著下降，磷含量則沒有太大差異。XRD結果發現當金屬塩比[Co(Co+Ni)]為0.1，繞射角度在44.4°有Ni(111)微晶相產生，且隨著金屬塩比增加變成非晶相。磁性分析結果發現當金屬塩比[Co(Co+Ni)]為0.7、0.9時，其飽和磁化強度最大為3.679emu/g。產氫方面發現隨著金屬塩比[Co(Co+Ni)]的增加產氫量也會增加，其中[Co(Co+Ni)]為0.9和0.95時產氫效果最好，硼氫化鈉40g/L，氫氧化鈉10g/L初始(前5分鐘)單位觸媒的產氫速率分別為704ml/min-g和3600ml/min-g，當鈷金屬塩比提高為0.95，發現15分鐘內每克的產氫量可達62000ml/g。
並列摘要
In this study, graphene oxide(GO) was prepared from natural graphite by using Hummers method first, and then was reduced to Graphene by Glycol, finally Co-Ni-P nanoparticles were deposited on Graphene to form Co-Ni-P/Graphene nanocomposite material by electroless Co-Ni plating. The effect of graphene and Co concentration upon the microstructures and hydrogen generation of Co-Ni-P/Graphene were investigated. The X-ray and TEM diffraction reveal that graphene is amorphous and Co-Ni-P/Graphene is nano-crystalline of Ni phase and Co phase. The experimental parameters of electroless Co-Ni plating include pH value of plating bath, and ratio of Co2+/(Ni2++Co2+). Experimental results show that Co-Ni-P nanoparticles of size 8~4 nm are uniform deposited on graphene at pH9, Co2+/(Ni2++Co2+)=0.9, 70℃, and plating for 1 minutes. The Co content of Co-Ni-P nanoparticles was analyzed by TEM/EDS, which shows that the Co content increases as the ratio of Co2+/(Ni2++Co2+) between 0.1~0.9 increases.Hydrogen generation of Co-Ni-P/Graphene by using 40g/L sodium borohydride increases as Co content increases, at the initial stage (about 5 minutes) the ratio of Co2+/(Ni2++Co2+)0.9 and 0.95 is 704 ml/g-min and 3600 ml/g-min,separately. Hydrogen generation of Co-Ni-P/Graphene at the ratio of Co2+/(Ni2++Co2+) 0.95 by using 40g/L sodium borohydride increases could reach 62000 ml/g for 15 min.