Harsasi Setyawati

Affordable dye sensitizer by waste

The development of dye sensitizer is growing in line with the increasing demand for renewable energy. A research to obtain a dye sensitizer that is economical, safe, and produces a great value of DSSC efficiency is a challenge unresolved. On the other hand, the efforts for waste reduction are also intensively conducted to create better environment. In this paper, the variation of synthetic dye wastes from batik industries have been successfully applied as dye sensitizer and fabricated on DSSC cells. Congo red (1.0133%) yielded higher efficiency than rhodamine B (0.0126%), methyl orange (0.7560%), and naphthol blue black (0.0083%). The divergence of the efficiency of DSSC is very dependent upon the chromophore group owned by dye. This study has proven that the more chromophore group possessed by dye, the higher the efficiency of DSSC generated. This research concludes that the dye wastes have a bright future to be implemented as dye sensitizer on solar cells.

Synthesis and characterization of Zn doped magnesium hydroxyfluoride, Mg1−xZnxFOH

A series of Zn-Doped Magnesium Hydroxyfluoride, Mg1−xZnxFOH) samples with 0 to 0.15 of x were prepared using a sol–gel synthesis and dried with vacuum technique. XRD characterization of the samples indicated the amorphous phase of Mg1−xZnxFOH similarity with MgF2. The Zn doped in magnesium hydroxyfluoride did not affected on the basic structure of magnesium hydroxyfluoride. The FTIR spectra showed the samples had a broad band at 3000-3700 cm−1 and 1620 cm−1 was indicated of adsorbed H2O molecules and a bridging hydroxyl groups, respectively. The intensity of the 460, and 550 cm−1 bands correlates to Mg-F and Mg-O vibrations. The Zn-O stretching vibration of Zn-doped magnesium hydroxyfluoride appeared at 1634 and 621 cm−1.

Characterization of a series nickel doped magnesium hydroxyflouride Mg1−xNixFOH with XRD and FTIR

A series nickel doped magnesium hydroxyfluoride, Mg1−xNixFOH has been prepared by fluorolytic sol-gel method. The x values in these series were from 0 to 0,15. The samples structure was obtained as amorphous phase from XRD characterization. The XRD patterns showed any peaks like the mixing between magnesium fluoride (selllaite) and magnesium hydroxide (brucite). The IR spectra from FTIR characterization of Mg1−xNixFOH samples indicated the peaks of OH bridging at 3630-3000 cm−1, Ni-OH vibration around 660-650 cm−1 Mg-O vibration around 550 cm−1, and Mg-F vibration at 460 cm−1.

The influence of dicarboxylic acids: Oxalic acid and tartaric acid on the compressive strength of glass ionomer cements

Glass ionomer cement (GIC) has limitation on the mechanical properties especially compressive strength. The change of compressive strength of GIC by adding oxalic acid and tartaric acid has been investigated. Oxalic acid and tartaric acid was added to the liquid components at concentrations of 0 – 15% (w/w). Powder component of GIC was made from optimum experimental powder glass SiO2-Al2O3-CaF2. GIC was characterized by compressive strength test, SEM-EDX and FTIR. The addition of tartaric acid to GIC has greater improvement than addition of oxalic acid. The addition of tartaric acid at 10 % (w/w) to GIC has greatest value of compressive strength.

Potential complex of rhodamine B and copper (II) for dye sensitizer on solar cell

A complex from copper(II) and rhodamine B as ligand was synthesized, characterized and applied as potential dye sensitizer on solar cell. A complex was synthesized from the reaction of copper(II) salts and rhodamine B with mole ratio 1:3. A complex showing Metal Ligand Charge Transfer (MLCT) phenomenon at 260 nm. Metal-ligand bonding through carbonyl (CO) groups at 617.22 cm-1 and methoxy (CH3O) groups at 339.47 cm-1. Electrical conductivity analysis confirms that the complex was ionic compound. The complex was applied as potential dye sensitizer with open circuit voltage 0.48775 V, short circuit current 0.01025 mA/cm2 and efficiency 0.0039 %.