Oxalic acid-assisted preparation of LTO-carbon composite anode material for lithium-ion batteries.

This study presents an oxalic acid-assisted method for synthesizing spinel-structured lithium titanate (Li4Ti5O12; LTO)/carbon composite materials. The Ag-doped LTO nanoparticles (NPs) are synthesized via flame spray pyrolysis (FSP). The synthesized material is used as a precursor for synthesizing the LTO-NP/C composite material with chitosan as a carbon source and oxalic acid as an additive. Oxalic acid improves the dissolution of chitosan in water as well as changes the composition and physical and chemical properties of the synthesized LTO-NP/C composite material. The oxalic acid/chitosan ratio can be optimized to improve the electrochemical performance of the LTO-NP/C composite material, and the electrode synthesized with a high mass loading ratio (5.44 mg cm-2) exhibits specific discharge capacities of 156.5 and 136 mAh g-1at 0.05 C- and 10 C-rate currents, respectively. Moreover, the synthesized composite LTO-NP/C composite material exhibits good cycling stability, and only 1.7% decrease in its specific capacity was observed after 200 charging-discharging cycles at 10 C-rate discharging current.

Aerosol processing technique for the synthesis of mixed-phase copper on carbon catalyst: insights into CO2adsorption and photocatalytic activity.

In this study, spray pyrolysis; an aerosol processing technique was utilized to produce a mixed-phase copper on carbon (Cu/CuxO@C) catalyst. The catalyst production was performed via chemical reduction of copper nitrate by a reducing sugar, i.e. glucose, using aqueous solution. The physical and chemical properties of the produced particles was assessed using various characterization techniques. The synthesis temperature had pronounced effect on the final particles. Since CO2adsorption onto the catalyst is an important step in catalytic CO2reduction processes, it was studied using thermogravimetric and temperature programmed desorption techniques. Additionally, photocatalytic activity of the particles was evaluated by gas-phase oxidation of acetylene gas which revealed excellent activity under both UV and visible light irradiation indicating the possible use of wider range of the solar spectrum.

A comparative study of magnetic chitosan (Chi@Fe3O4) and graphene oxide modified magnetic chitosan (Chi@Fe3O4GO) nanocomposites for efficient removal of Cr(VI) from water.

Magnetic chitosan (Chi@Fe3O4) nanocomposite was synthesized and modified with graphene oxide (Chi@Fe3O4GO) and the potential of both materials as adsorbents was assessed for the removal of chromium (Cr(VI)) from water. The physico-chemical characteristics of magnetic nanocomposites were studied by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), x-ray diffraction (XRD), Raman spectroscopy and Brunauer-Emmett-Teller (BET). The synthesized adsorbents exhibited varied Cr(VI) removal efficiency at solution pH 2. The reaction kinetics correlated well with the pseudo-second-order model. The maximum adsorption capacity was found to be 142.32 and 100.51 mg g-1 for Chi@Fe3O4 and Chi@Fe3O4GO, respectively. Analysis of thermodynamic parameters suggested that the reaction occurred spontaneously and was endothermic in nature. Reusability studies showed that the adsorbents can be reused for up to four cycles of regeneration. Fixed bed column experiments revealed that the adsorption performance of Chi@Fe3O4 was affected by the flow rate, adsorbent loading and influent metal ion concentration. The results suggest that the prepared adsorbents have the potential to be used in removing Cr(VI) ions from contaminated water.