Bio-organic Molecules Assisted Synthesis Of Nano-oxide And Functionalization Of Graphenes

In this paper, several oxides were synthesized using biomolecule-assisted hydrothermal/solvothermal approaches, and both the organic and inorganic functionalizations of graphene were studied. The obtained products wre characterized by XRD, SEM, TEM, HRTEM, AFM, FT-IR, Raman, XPS and PL. Their properties of were also investigated, and their applications in the energy field were prospected. The main contributions are presented as follows.Monodisperse MoO3nanowires with length above60μm were synthesized using a novel L-aspartic acid-assisted hydrothermal approach. The ultra-long MoO3wires exhibit a good cyclability when used as a active electrode material in pseudocapacitors.Monodisperse superparamagnetic Fe3O4nanocubes with the edge length up to approximately16nm were synthesized by using an L-serine-assisted solvothermal approach. The Fe3O4nanocubes were characterized by XRD, Raman, FT-IR, TEM, and HRTEM. The magnetic properties of the Fe3O4nanocubes were studied by zero-field cooling (ZFC) and field cooling (FC) procedures, i.e., M-T and M-H curves. The electrochemical behavior of the Fe3O4nanocubes was tested in lithium ion batteries, which presents a high specific capacitance of695.1mAh/g at0.2C, much higher than that of commonly used graphite electrode (372mAh/g), as well as excellent coulombic efficiency of above95%after the11th cycle.Three dimensional SnO2-based nanocomposites, i.e., SnO2nanoparticles anchored on polyaniline nanoplates@reduced graphene (SPG) via π-π stacking, present excellent cyclability and high capacity with a reversible storage capacity of573.6mAh/g accompanied by coulombic efficiency of99.26%over50cycles when used as an anode in a lithium ion battery.N-doping of graphene was performed through a congo red acylation reaction with GOC1from graphene oxide (GO), leading to the formation of nanocomposite, i.e., congo red-modified graphene oxide (termed as CMG), which belongs to N-type electronic doping graphene. The nanosheets were characterized by FT-IR, Raman, XPS, TGA, UV-vis, PL, TEM, and AFM. The CMG nanocomposite can be used as electrode materials in supercapacitors with excellent cyclability evaluated by continuous charge/discharge measurements over2000cycles with the retention efficiency over88%, as well as specific capacitance of156F/g, energy density of3.5Wh/kg, and power density of81W/kg at a discharge current density of200mA/g, presenting enhanced electrochemical behavior over GO electrode material.