MAGNETIC REDUCED GRAPHENE OXIDE AS ADVANCED MATERIALS FOR ADSORPTION OF METAL IONS

MAGNETIC REDUCED GRAPHENE OXIDE AS ADVANCED MATERIALS FOR ADSORPTION OF METAL IONS. Magnetite (Fe₃O4) Reduced Graphene Oxide (MRGO) is graphene-based material that modified by introducing of Fe₃O4 nanoparticles onto the surface of graphene oxide (GO). MRGO exhibit some unique and advanced properties and characteristic including high surface area, superparamagnetic characteristics and adsorption ability against ions and molecules. In this research, GO was prepared by the Hummers method, followed by reacting FeCl₂.4H₂O and FeCl₃.6H₂O through co-precipitation method for the formation of magnetite nanoparticles on the graphene surface. MRGO was prepared with various composition of ferrochloride tetrahydrate (FeCl₂.4H₂O). Furthermore, the resultant of MRGO was characterized by Scanning Electron Microscope (SEM), Fourier-transform Infrared (FTIR) Spectroscopy, X-ray diffraction (XRD) and Atomic Adsorption Spectroscopy (AAS). Adsorption characteristics test was conducted against electroplating waste-based metal ion.  The SEM results showed that GO exhibited the layered structure meanwhile MRGO exhibit as a Fe₃O4-modified GO layered surfaces. Furthermore, MRGO made by different ferrochloride tetrahydrate differed in the Fe₃O4 nanoparticles formation on the surface of GO. Increasing the composition of ferro chloride tetrahydrate increased the formation of Fe₃O4. MRGO developed as a superparamagnetic material which could easily interact during the external magnetic field applications and this character will easily disappears when the magnetic field is removed. Moreover, MRGO (FeCl₂.4H₂O 0.0064M) is successfully applied as nickel metal ion (Ni2+) adsorbents with the adsorption ability of 78,24%. This results showed that MRGO have a potential prospect as an effective and efficient adsorbent advanced material candidate

Study of Reduced Graphene Oxide addition on the Electrical Conductivity and Flexural Strength of Metakaolin-based Geopolymer

Geopolymer with reduced Graphene Oxide (rGO) composite obtanined through Hummers method. This material is a substitute option for graphene because the nature of rGO is easier to produce in large quantities. In theory, it is expected that rGO can increase the flexural strength and electrical conductivity of geopolymer. The rGO composition used varies from 0-1 wt%. Geopolymer and their constituents were characterized by the Three Point Bending, EIS, SEM, FTIR, XRD, and XRF tests. Fly ash-based geopolymers have a flexural strength of 5.2 MPa at a composition of 0.5 wt% rGO, while metakaolin-based geopolymers with an addition of 0.25% rGO produce the highest flexural strength of 5.53 MPa. A frequency of 100,000 Hz tends to facilitate greater electrical conductivity, on fly ash-based geopolymers found electrical conductivity of 5.08 x 10-3 S / m, while for metakaolin-based geopolymers the electrical conductivity is higher ie 1.01 x 10-1 S / m.

Preparation and characterization of biomass-derived advanced carbon materials for lithium-Ion battery applications

In this study, carbon-based advanced materials for lithium-ion battery applications were prepared by using soybean waste-based biomass material, through a straightforward process of heat treatment followed by chemical modification processes. Various types of carbon-based advanced materials were developed. Physicochemical characteristics and electrochemical performance of the resultant materials were characterized systematically. Scanning electron microscopy observation revealed that the activated carbon and graphene exhibits wrinkles structures and porous morphology. Electrochemical impedance spectroscopy (EIS) revealed that both activated carbon and graphene-based material exhibited a good conductivity. For instance, the graphene-based material exhibited equivalent series resistance value of 25.9 Ω as measured by EIS. The graphene-based material also exhibited good reversibility and cyclic performance. Eventually, it would be anticipated that the utilization of soybean waste-based biomass material, which is conforming to the principles of green materials, could revolutionize the development of advanced material for high-performance energy storage applications, especially for lithium-ion batteries application