Co2SiO4 nanostructures: New simple synthesis, characterization and investigation of optical property

Abstract

Herein, a new and simple method for the synthesis of Co 2 SiO 4 nanostructures at low temperature is reported. The nanostructures are obtained by the solvothermal reaction of Co(CH 3 COO) 2 .4H 2 O with tetraethyl orthosilicate (TEOS) in methanol solvent at 120-150 ˚C for 8−12 h, follows by calcination at 700 ˚C for 5 h. The effects of using polymer, mole ratio of Co:Si, reaction time and temperature have been optimized to achieve the best products on morphology and purity. It is the first time that optical property of cobalt orthosilicates and also effect of polymer on them are investigated. At the temperature of 150 ˚C for a 12 h period of time, when the molar ratio of Co:Si is 1:1, the product is rod-shape Co 2 SiO 4 with diameters of 20−40 nm. A mixture of the rod-shape and spherical structures of Co 2 SiO 4 , with diameters of 20−40 nm, is obtained by making use of ratio of 2:1 of Co:Si at 150 ˚C for 12 h. With a decreasing reaction time to 10 h, spherical clusters of Co 2 SiO 4 is prepared. The Co 2 SiO 4 nanostructures are characterized by XRD, SEM and TEM to analyze their structure and morphology. The optical and magnetic properties of the nanostructures are investigated.

Template-Free Synthesis of Cobalt Silicate Nanoparticles Decorated Nanosheets for High Performance Lithium Ion Batteries

“…XRD pattern of Co 2 SiO 4 nanoparticles decorated nanosheet calcined at 1100 °C is shown in Figure a. It is well-known that Co 2 SiO 4 prepared by the hydrothermal method is usually amorphous or low crystalline. ,,, And the amorphous Co 2 SiO 4 can be transformed into crystalline Co 2 SiO 4 by high temperature calcination. Here, 900 and 1100 °C were used as the calcination temperatures.…”

“…However, high temper-ature (above 900 °C) will lead to the aggregation of the materials during the solid-state reactions. 35,36 On the other hand, template is required for the preparation of Co 2 SiO 4 through hydrothermal reactions, which complicates the synthetic procedure. 27,31,37−40 Herein, a one-pot template-free hydrothermal method is presented for the first time to prepare hierarchical amorphous high specific surface area (161.7 m 2 g −1 ).…”

“…Transition metal silicates, such as nickel silicate, − manganese silicate, − copper silicate, cobalt silicate, , etc., have recently been explored as a special kind of electrode materials for LIBs. − Among them, Co 2 SiO 4 is particularly promising due to its high theoretical capacity (∼1500 mAh g –1 ), good stability as well as facile preparation. − At present, solid-state reaction and hydrothermal reaction are usually applied to synthesize Co 2 SiO 4 . However, high temperature (above 900 °C) will lead to the aggregation of the materials during the solid-state reactions. , On the other hand, template is required for the preparation of Co 2 SiO 4 through hydrothermal reactions, which complicates the synthetic procedure. ,,− …”

Photothermal Catalytic Reduction of CO2 by Cobalt Silicate Heterojunction Constructed from Clay Minerals

“…The Si 2p of Co2SiO4 is located at the binding energy of 102.75. The Si 2p characteristic peaks of Co2SiO4/Co3O4 composites exhibit lower binding energy and weaker peaks than Co2SiO4, which may be due to the formation of Si-O-Co bonds on the surface [23].…”

Correlation between degree of crystallinity and bluing of Zn1–Co Al2O4 (0≤x≤1) nanopowders prepared by soft chemistry route

“…Their absorption properties are governed by the degree of oxidation of the transition metal and by its environment in the crystal lattice [1][2][3][4]. Usually the main source of the blue colour is the cobalt that can be introduced in different structures, such as Co 2 SiO 4 (olivine) [5], (Co, Zn) 2 SiO 4 (willemite) [6,7] and CoAl 2 O 4 (cobalt spinel) [8]. Admittedly, the use of cobaltbased blue pigments in the ceramic industries leads to a more intense shade, after treatment at high temperature, but this metal is expensive which increases the manufacturing cost.…”