Reduced graphene oxide (rGO) and NiO composites were prepared with an environmentally friendly method, in which hydrogen gas was employed as the reducing agent to convert reduced graphene oxides. Our study indicates that the success of this new approach is because NiO not only is an additive of the composites but also acts as a catalyst to facilitate the reduction. Characterization with scanning electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and X-ray powder diffraction illustrates that the as-prepared rGO/NiO composites have a three-dimensional flowerlike hierarchical structure, which prevents graphene from taking face to face aggregation and therefore greatly improves the stability of the composite materials. A hybrid capacitor electrode made of the NiO/rGO composites shows great performance, in which the maximum specific capacitance is close to 428 F g–1 at a discharge current density of 0.38 A g–1 in a 6.0 M KOH electrolyte.

Te@Pd core–shell hybrids were prepared in this study, in which a pine leaf-shaped microstructure was obtained through controlling the synthesis kinetics of single crystal Te. The as-prepared Te was subsequently utilized as the substrate for Pd coating. These core–shell particles were characterized with scanning and transmission electron microscopy, high resolution transmission electron microscopy, X-ray diffraction, and energy dispersive X-ray spectroscopy. When being applied as a catalyst in bromobenzene and phenylboronic acid reaction, 100% conversion of bromobenzene was achieved in less than 3 h, which was much shorter than that required by the reactions using graphene oxide supported Pd catalyst (4 h) or the commercial Pd/C catalyst (>6 h). The Te@Pd core–shell catalyst could be easily recovered from the reaction solution and be used repeatedly. The high catalytic activity of Te@Pd hybrids is attributed to their unique microstructure.