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PEMBUATAN LAPISAN TIPIS MANGAN OKSIDA DAN LITIUM-MANGAN OKSIDA PADA SUBSTRAT KACA DENGAN METODA DIP-COATING MELALUI PROSES SOL-GEL Warda Ningsih, Sherly Kasuma
Sainstek Vol5, No 1, 2010
Publisher : Jurnal Sainstek

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (46.965 KB)

Abstract

Preparation of manganese oxide and lithium-manganese oxide thin layer on glass substrate by dip-coating method via sol-gel process have been investigated. Manganese (II) nitrate tetrahidrate and lithium chloride were used as precursors, isopropanol as solvent and DEA as additive. Dip-coating process have been done on glass substrate at 6 times with dipping time around 2 minutes for each layer process and dried at 110-120 oC around 15 minutes. Dried samples heated at 400 oC, 500oC and 600oC during 120 minutes. Black thin layer were obtained as products. The products were characterized by X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The XRD pattern was shown manganese oxide thin layer were obtained Mn2O3 only. Crystal structure of Mn2O3 was orthorombic with crystallite size around 13.0 nm (JCPDS No. 24-0508). SEM image (at 500oC) showed uniform and smooth surfaces with grain size around 0,01 m. The XRD patterns showed that lithium-manganese oxide thin layer were obtained LiMn2O4 and small amount of Mn2O3. Crystal structure of LiMn2O4 was spinnel with crystallite size around 16.86 nm (JCPDS No. 35-0782). SEM images (at 400 and 500oC) showed fiber form were produced generally and spheric form at 600oC. Key words : lithium-manganese oxide, dip-coating, sol-gel, fiber, spheric,
Deteksi Formaldehida Menggunakan Glassy Carbon Electrode (GCE) Modifikasi Lapisan Tipis Emas secara Voltametri Siklik Maharani, Indah Kemala; Sari, Trisna Kumala; Dewata, Indang; Warda Ningsih, Sherly Kasuma; Yamesa Away, Romy Dwipa
Periodic Vol 13, No 1 (2024): PERIODIC
Publisher : Departemen Kimia FMIPA UNP

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/periodic.v13i1.124526

Abstract

The formaldehyde was found as one of the toxic and mutagenic products. Long-term exposure will harm the health of the human body. This study aims to detect formaldehyde developed on an electrochemical sensor using Glassy Carbon Electrode (GCE) modified with a thin layer of gold as the working electrode by cyclic voltammetry. Electrode modification was carried out by electrodeposition of Au potential-sweeping on electrodes known as Au/GCE electrodes. The resulting electrode has high conductivity and excellent catalytic activity because it is able to provide a large peak current response. In this study, the optimum conditions will be determined based on variations in the electrodeposition cycles of gold thin films and variations in the supporting electrolyte. The optimum cycle of gold thin film electrodeposition was obtained, namely one cycle and 0.1 M KOH as the optimum supporting electrolyte. The peak current obtained is sharper, the sensitivity and stability are also better due to the electrocatalytic properties produced by the high gold thin layer.
Effect Type of Desorption Eluent and Concentration in Desorption of Zn2+ Cation from Sulfonate Modified Silica Gel-GPTMS (Glycydoxypropyltrimethoxysilane) Adsorbent Hafis, Muhamad; Oktavia, Budhi; Alizar, Alizar; Warda Ningsih, Sherly Kasuma
Indonesian Journal of Chemical Science and Technology (IJCST) Vol 7, No 2 (2024): JULY 2024
Publisher : Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24114/ijcst.v7i2.62256

Abstract

Silica has silanol groups contained in it which have low binding ability because it has low acidity, resulting in low absorption effectiveness on silica. In order to improve the properties and to expand the field of utilization, a modification process is carried out on silica gel using GPTMS bridging compounds and sulfonate salts as modifiers. The study explains that CaCl2.2H2O with a desorption percent of 97.25% has a greater ability than NaCl which is only 83.93% in the desorption of Zn2+ cations. The study also explains that the optimum concentration of CaCl2.2H2O eluent in the desorption of Zn2+ cations is at 1mmol/L where the desorption yield is 93.74%.
PEMBUATAN Dye (Zat Warna) BERBAHAN DASAR KUBIS MERAH (Brassica Oleracea L.) DENGAN METODE MASERASI Wardah Nabila Putri; Sherly Kasuma Warda Ningsih
Jurnal Crystal : Publikasi Penelitian Kimia dan Terapannya Vol. 7 No. 2 (2025): Literasi Artikel Penelitian Kimia
Publisher : Program Studi Kimia, Fakultas MIPA, Universitas PGRI Banyuwangi

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.36526/jc.v7i2.6149

Abstract

DSSC fabrication using expensive and difficult to obtain synthetic dye sensitizers can be overcome by utilizing natural dyes from red cabbage. Dye or dye functions as a compound that absorbs sunlight. This study aims to explore the characteristics of anthocyanin pigments extracted from natural materials, namely red cabbage (Brassica Oleracea) as a dye-sensitizer in Dye Sensitized Solar Cell (DSSC) type solar cells. Anthocyanin pigments were chosen because of their ability to absorb light in a broad spectrum, their environmentally friendly nature, and their abundant availability in nature. Pigment extraction was carried out using 70% ethanol solvent and characterization was carried out using Fourier Transform Infrared Spectroscopy (FTIR) and UV-Visible (UV-Vis). The results of the FTIR analysis showed anthocyanin. UV-Vis analysis showed an absorption peak at a wavelength of 323 nm. The results of this study indicate that anthocyanin pigments from natural materials have the potential as effective and environmentally friendly dye-sensitizers in the development of DSSC
ANALISIS SPEKTROFOTOMETRI EKSTRAK BUNGA TELANG BERDASARKAN VARIASI WAKTU MASERASI SEBAGAI KANDIDAT SENSITIZER PADA DYE SENSITIZED SOLAR CELL (DSSC) Fadia Mutiara Putri; Sherly Kasuma Warda Ningsih
Jurnal Crystal : Publikasi Penelitian Kimia dan Terapannya Vol. 7 No. 2 (2025): Literasi Artikel Penelitian Kimia
Publisher : Program Studi Kimia, Fakultas MIPA, Universitas PGRI Banyuwangi

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.36526/jc.v7i2.6221

Abstract

Increasing population growth causes an increase in energy demand, which causes global warming and climate change. Therefore, a renewable energy source is needed, namely solar energy. DSSC offers the potential for lower production costs compared to conventional solar cells. However, currently the commonly used sensitizer is ruthenium-based which is expensive and harmful to the environment. Therefore, a natural sensitizer is sought, namely from butterfly pea flowers which contain anthocyanin pigments that can absorb light and convert it into electrons. The purpose of this study was to determine the functional groups of butterfly pea flowers and determine the effect of maceration time on the maximum wavelength of butterfly pea flower extract as a sensitizer candidate in DSSC. The method used was maceration of butterfly pea flower powder using 70% ethanol solvent with variations in maceration time, namely 24 hours, 48 hours and 72 hours. Spectrophotometric analysis was carried out using FTIR to determine the functional groups contained in butterfly pea flowers and UV-Vis to determine the maximum wavelength in butterfly pea flower extract. The result is that there is a strong absorption band at a wave number of 3279.96 cm-1 indicating the presence of O-H group stretching which indicates that the butterfly pea flower is rich in anthocyanins. The maximum wavelength of the butterfly pea flower is that there are 2 peaks at 576 nm and 621 nm. Variations in maceration time do not affect the maximum wavelength of the butterfly pea flower but affect the absorbance, the lowest absorbance is 24 hours of maceration time followed by 48 hours of maceration time and the highest is 72 hours of maceration time. The conclusion is that the main compound contained in the butterfly pea flower is anthocyanin and 72 hours of maceration time shows the highest absorbance so it can be used as the most optimal sensitizer candidate.