Graphene-Oxide-Directed Hydrothermal Synthesis of Ultralong M(VO₃)_n Composite Nanoribbons

Abstract

New strategies for 1D materials fabrication are of fundamental importance in the advancement of science and technology. Instead of small organic amines molecule-and the polymer-directed agent, here, we report a unified graphene-oxide-directed agent to the synthesis of a series of nanoribbons with different chemistries and with low dispersity, including V 2 O 5 , AgVO 3 and Sr(VO 3 ) 2 . This strategy is based on a general linear growth of vanadate and splitting mechanism of graphene oxide during the synthesis. We believe our methodology provides a simple and convenient route to a variety of nanoribbon building blocks for assembling materials with novel structure and function in nanotechnology. More importance is that graphene is in the middle of composite structure, while supporting the main structure it does not affect the mass transfer process. Compared to other composite structures based on graphene, such as graphene scroll and graphene sheet, graphene ribbon is more suitable for lithium-ion battery. INTRODUCTIONThe nanoribbons are important for certain devices because they provide, for example, ultrahigh aspect ratios which is extremely sensitive to surface-adsorbed species for chemical sensing and geometries with high carriers that could efficiently fill the channel regions of transistors. 1, 2 Currently, Major efforts have been placed on methodology development for nanoribbon synthesis, assembly and property elucidation. However, the bulk of previous studies is limited to simple Si, Ge and binary semiconductor, with only a few recent investigations into complex system such as, superlattice nanoribbons and ternary compounds. [3][4][5] Although studies of ternary nanoribbons, in comparison with binary ones, are relatively more meaningful because the ternary nanoribbons exhibit not only more complex functions but also properties that are readily tunable by changing the component element, 6 a significant bottleneck in the field is the lack of a general approach to the synthesis of nanoribbon building blocks composed of complex functional materials (e.g., ternary and even quaternary systems). This is mainly due to the traditional methods such as chemical vapor deposition and etching which are applicable to the synthesis of binary compounds are not suitable for that of ternary compounds. 7, 8 Grow techniques related to the well-developed solvothermal and hydrothermal synthetic approaches used for nanoribbons have been adapted and applied with some success to produce ZnGeO 4 nanoribbon. 9 Nevertheless, a widely employed hydrothermal route for synthesizing nanobelts is the use of templates, surfactants or structure-directing agent, including a variety of small organic amines molecules and the polymers. 9, 10 Moreover, formally in order to make less affection on the properties, the sample has to be washed or calcined for eradicating the structure-directing agents. Furthermore, there is no structure-directing agent suitable for the synthesis of a series of nanoribbons.

Freestanding, Hierarchical, and Porous Bilayered NaxV2O5·nH2O/rGO/CNT Composites as High-Performance Cathode Materials for Nonaqueous K-Ion Batteries and Aqueous Zinc-Ion Batteries

“…In the early stage of the hydrothermal process, the Na–V–O intermediate is converted into free molecule-like vanadium (V) species such as [V 10 O 28 ] 6– and [VO 2 ] + , and there are abundant active sites on the GO and CNTs (e.g., defects and oxygen-containing functional groups) . These active sites likely lower the energy barrier of the interface between the solid surface and solution , to facilitate nucleation and growth along the [010] direction of layered V 2 O 5 . With the hydrothermal reaction being prolonged, these vanadium species self-assemble to form nanobelts with the δ-Na x V 2 O 5 · n H 2 O phase, followed by trapping of water molecules and Na + between the bilayers of V 2 O 5 .…”

Advances in Subcritical Hydro‐/Solvothermal Processing of Graphene Materials

“…Other complex oxides which have high electrochemical activity such as Li 4 Ti 5 O 12 , NiMoO 4 , CdFe 2 O 4 , and CuFe 2 O 4 were also coupled with graphene through solvothermal crystallization route. Similarly metal oxide semiconductors such as Co 3 O 4 , MoO 3 SnO 2 , MnO 2 , Mn 3 O 4 , VO 2 , RuO 2 , Fe 3 O 4 , Cu 2 O, Bi 2 O 3 , Cr 2 O 3 , and WO 3 , V 2 O 5 , metal sulfides such as ZnS, NiS, CuS, CdS, Ni 3 S 2 , MoS 2 , VS 2 ,Ce doped SnS 2 , CuInS 2 , and Co 9 S 8 , metal nanoparticles such as Ni, were successfully integrated into graphene through solvothermal routes. The combination of metal oxide or metal sulfides with graphene resulted in the excellent capacitance activity and long cycling stability of the resultant composites.…”

Active vanadium(iv) species synthesized at low-temperature facilitate excellent performance in low-temperature NOx-catalytic removal

“…The binding energies for V 2P 3/2 and 2P 1/2 agree well with those of V 5+ and V 4+ , respectively. 29,30 We also tabulated (Table 1) the percentage of V-species associated with the V 2P spectral peak. The comprehensive analysis of the results of 51 V NMR and V 2P XPS shows that the proportion of V 4+ and V 5+ in the bulk phase of V 260°C is close to 1 : 1, and the ratio on the surface is close to 3 : 7.…”