The TEM images of the RGO-GeNPs showed that the GeNPs with diameters of 200 nm were deposited on the basal planes of RGO with less wrinkles in Figure 1c,d. The reasons that caused wrinkle reduction were that the GeNPs adsorbed on the reduced graphene oxide layers resulted in the stretching MCC950 concentration of its wrinkles, and under the action of reducing agent NaBH4, the hydrophilic group -COOH,-OH, etc. on the surface of GO decreased [26] and the hydrogen bonding lowered, causing a reduction of the wrinkles. When the reduction was carried out in the presence of PSS, the average size of the GeNPs further decreased, and the dispersibility has significantly improved, as shown in Figure 1e,f.

An authentic photograph of the PSS-RGO-GeNP solution was given in the inset of Figure 1e. Stable aqueous dispersibility of RGO-GeNPs was further improved in the presence of PSS. Figure 1 TEM images of GO, RGO-GeNPs and PSS-RGO-GeNPs at different magnifications. (a,b) GO. (c,d) RGO-GeNPs. (e,f) PSS-RGO-GeNPs. Formation mechanism of RGO-GeNPs Figure 2 showed a schematic Anlotinib cost illustration of the synthesis route for the RGO-GeNPs and PSS-RGO-GeNPs. The formation

process of the nanocomposites could be divided into two stages. In the first stage, the oxygen-containing groups on GO could also provide plentiful sites to anchor GeO3 2- and make them enrich in some places. Consequently, GeO3 2- was homogeneously dispersed in GO by ultrasonic treatment. In the

MLN2238 solubility dmso second stage, the GO nanosheets and the Ge ions could be reduced in situ by sodium borohydride, resulting in GeNP loading on graphene nanosheets to fabricate the RGO-GeNPs. Furthermore, stable black aqueous dispersions Etofibrate of PSS-RGO-GeNPs was obtained by coating an amphiphilic PSS. Figure 2 Schematic illustration of the preparation of the RGO-GeNPs and the PSS-RGO-GeNPs. The stable dispersions of the PSS-RGO-GeNPs were also analyzed by UV–vis spectroscopy. The UV–vis spectrum of the PSS-RGO-GeNPs in water possesses similar features as that of the PSS itself at approximately 262 nm (Figure 3a). A rising absorption edge from 550 nm into the UV gives an evidence of the PSS-RGO-GeNPs. The FTIR spectrum of RGO-GeNPs at 781 cm-1 showed the formation of Ge-N bond, clearly indicating the interaction between RGO and GeNPs. Although the FTIR spectrum of PSS-RGO-GeNPs exhibits weak PSS absorption features, it only confirms the presence of the PSS component (Figure 3b). Figure 3c showed a powder XRD pattern for a representative sample of as-synthesized GeNPs, which was in agreement with the standard value for Ge (JCPDS card no. 89–5011). An elemental composition analysis employing EDS showed the presence of a strong signal from the Ge atoms, together with C atom and O from the graphene molecules, whereas a Cu atom signal was ascribed to the supporting grid (Figure 3d).