A bean-like formation of germanium nanoparticles inside CNTs by the subsequent operation of colloidal synthesis and catalytic chemical vapor deposition methods

Karatutlu, AliBoi, F. S.Wilson, R. M.Ersoy, O.Ortac, BülendSapelkin, A.2019-02-212019-02-2120180232-1300http://hdl.handle.net/11693/49884The first attempts of implanting Ge nanoparticles (Ge NPs) inside iron filled CNTs (IF-CNTs) by a subsequent use of the bench top colloidal synthesis and chemical vapor deposition (CVD) approach is shown. Ge NPs are colloidally synthesized (with a 3.8 ± 0.6 nm in size) before the deposition. The hybrid Ge NPs/IF-CNTs structure and morphology are characterized using high-resolution transmission electron microscopy, scanning electron microscopy, selective area electron diffraction, and X-ray diffraction studies. After the deposition, Ge NPs appear to be grown in size and to be sprinkled almost homogeneously into the IF-CNTs similar to a bean-like deposition. CNTs diameter is also identified to be enlarged drastically when using Ge NPs as a catalyst in CVD compared to the CNTs formation without Ge NPs. In addition, micro-length rectangular Ge µPs are also found outside the nanotube core. Rietveld analysis shows the presence of γ-Fe (Fm-3m), ferromagnetic α-Fe (Im-3m), Fe3C, Ge (Fd-3m), and multiwall CNTs. The results indicate that Ge NPs and IF-CNTs demonstrate cocatalytic activity in increasing the respective sizes, which are dramatically larger than those obtained by the conventional approaches.EnglishChemical vapor depositionCNTsColloidalFerromagnetismGermaniumNanoparticlesA bean-like formation of germanium nanoparticles inside CNTs by the subsequent operation of colloidal synthesis and catalytic chemical vapor deposition methodsArticle10.1002/crat.2018001231521-4079