Nitrogen doping into graphene was carried out by heating Graphene Nano Sheets (GNS) in ammonia to produce N‐doped graphene (N−G). The N−G was used as a support material for Pt catalyst as well as a catalyst itself for half‐cell cathode reaction of hydrogen fuel cell (H2FC). It is found that the Oxygen Reduction Reaction (ORR) electro catalytic activity for N−G 900 (0.63 V versus RHE) is higher than GNS. It indicates that the incorporation of nitrogen in N−G may affect the ORR activities. XPS results exhibit the pyridinic N is the majority in N−G, where the pyridinic N refers to N atom bonds with two C atoms at the edges or defects of graphene. Interestingly, the Pt subnano‐clusters were formed on all of Pt/N−G catalysts with Pt particle size (0.7–1.0 nm). It clearly indicates that the doping of nitrogen significantly influence π–d hybridization in terms of electronic structures.

Since graphene was first isolated in 2004, it has become an attractive material on electrochemical energy storage devices. The purpose of this study is to compare Mg/graphite and Mg/graphene electrodes to commercial primary battery cathodes. This research is an experimental laboratory research. Graphene was synthesized with Hummer's method modified. Electrodes cathode of primary battery (Mg/graphite and Mg/graphene) were prepared using impregnation method. Graphene and electrodes cathode were analyzed with X-Ray Diffraction (XRD), Scanning Electron Microscope-Energy Dispersive X-Ray (SEM-EDX) and conductivity, respectively. The XRD data of graphene show that there is a weak and sharp peak on 2θ ¼ 26,5 o , indicating graphene is formed. The peaks shape of 2θ ¼ 35 o are totally different for Mg/graphite and Mg/graphene. At Mg/graphite, the sharp and narrow peak appears on 2θ ¼ 35 o . It means Mg is well deposited on graphite. Interestingly, Mg/graphene has narrow and weak peak on 2θ ¼ 35 o , indicating the Mg was deposited on graphene and properties of Mg has been changed by graphene. This data is also well confirmed by EDX data. Mg atoms exist on graphene (1.47 wt%) (EDX data). SEM images of Mg/graphite and Mg/graphene are significantly different, probably support material effect. The properties of Mg/graphite and Mg/graphene comparing to commercial primary battery cathode were evaluated using conductivity. The conductivity of Mg/graphene (1080 μS/cm) is highest among Mg/graphite (90 μS/cm) and commercial battery cathode (10 μS/cm). All of data show that the Mg/graphene is potentially used as a primary battery cathode.

Synthesis of silica gel base on Mount Sinabung's volcanic ash taken from different villages, was carried out. The purposes of this research are to synthesis and characterized by silica gel which was generated base on ash. The method of this research is a sol-gel method. T h e silica gel w as characterized by Fourier Transform Infra Red (FTIR), X-Ray Diffraction (XRD), and Barret Emmet Teller (BET) respectively. The silica gel consists of Si-O-Si and Si-OH groups. XRD data also shows that silica is amorphous. BET data show that the surface area of silica gel is 374.994 m²/g. A fix bed Column of silica gel was used for the removal of Cd(II). The adsorption column used has a diameter of 1.7cm and is filled with 0.5g of silica. the optimum adsorption capacity is: flow rate 4mL / min (21,194 mg / g). The initial optimum concentration is 24 ppm (21.632 mg / g). The optimum pH is pH 6, (21.848 mg / g). The experiment result showed silica adsorbent effective for removal Cadmium

No abstract

Essential oils are volatile oils with different compositions according to their source of production and comprise a mixture of substances having different chemical and physical properties. One of the plants containing essential oil is Eucalyptus grandis grown at PT Toba Pulp Lestari (Indonesian company). The purpose of this work is to know the chemical contents and physical properties of essential oil from Eucalyptus grandis as well as to utilize unused leaves at PT. Toba Pulp Lestari to serve as an essential oil. The essential oil of Eucalyptus grandis leaves was extracted using hydrodistillation method, then essential oil is analyzed by GC-MS. The essential oil of Eucalyptus grandis leaves was obtained 0.4 %. The physical properties test with determination of density and refractive index of essential oil respectively were obtained at 0.9143 and 1.4653 nD at 29.4 ºC. The results of GC-MS analysis of essential oil showed 12 components viz. α-pinene (45.21 %), camphene (1.38 %), β-pinene (1.11 %), camphogen (0.74 %), 1,8-cineole (36.55 %), α-campholene aldehyde (0.73 % ), pinocarvone (0.83 %), α-terpineol (8.87 %), β-caryophyllene (1.72 %), spathulenol (0.84 %), elemol (0.85 % ) and 1-nonadecene (1.17 %).