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Potensi Ekstrak Kasar Teh Hitam (Camellia sinensis O.K. var. Assamica) sebagai Pewarna (Dye) pada Pembuatan Sela Surya Tersensitisasi (SSPT) Deskawi, Oki; Ningsih, Rachmawati; Avisena, Novi; Hastuti, Erna
ALCHEMY ALCHEMY (Vol.4, No.1
Publisher : Department of Chemistry, Faculty of Science and Technology UIN Maulana Malik Ibrahim Malan

Has done research on the manufacture of dye sensitized solar cells by utilizing the crude extract of black tea (Camellia sinensis var O.K. Assamica). This study aims to determine the potential of black tea extract as a dye in dye sensitized solar cell manufacturing. This study includes several stages: sample preparation of black tea, black tea sample extraction in a mixture of acetic acid: methanol: distilled water (4:25:21), analysis of the crude extract of black tea using UV-Vis, color density analysis using a color reader, testing DSSC obtained by measuring voltages and currents strong produced under conditions halogen lamp illuminated with a light intensity of 4.488 Watt/m2, the identification number of the crude extract of pigments by TLC analytical. The results of the characterization black tea extract is flavonoids. That it contains theaflavins shown with a maximum wavelength 273 nm. Color of black tea using a color reader testing showed reddish yellow (orange) with the color density reached 78,3%. Voltage maximum and maximum current strength produced by 107,3 mV and 2.13 x 10 -3 mA. The efficiency of the resulting solar cell system by 1,26 x 10 -2%. The results of the identification of the amount of pigment produced 8 spot with eluent ethyl acetate: formic acid: distilled water.Â Keywords: Dye sensitized solar cells, dye (dye), theaflavin

PENGARUH PENDOPINGAN Y2O3 TERHADAP STRUKTUR DAN RELAKSASI DIPOLE Ba0,95Sr0,05TiO3 Erna Hastuti; Suasmoro Suasmoro
Jurnal Sains Materi Indonesia Vol 7, No 2: FEBRUARI 2006
Publisher : Center for Science & Technology of Advanced Materials - National Nuclear Energy Agency

PENGARUH PENDOPINGAN Y2O3 TERHADAP STRUKTUR DAN RELAKSASI DIPOLE Ba0,95Sr0,05TiO3. Komposisi Ba0,95Sr0,05TiO3 disintesis melalui kalsinasi prekursor yang diperoleh melalui kopresipitasi oksalat. Bubuk didoping dengan Y2O3 dengan kadar % mol Y3+: 0; 0,2; 0,4 dan 0,6. Pengaruh doping Y3+ terhadap sampel dianalisis melalui difraksi sinar X, permitivitas, resistivitas dan konduktivitas. Diperoleh data bahwa sampel yang didoping mempunyai tetragonalitas yang lebih kecil dibandingkan dengan sampel tanpa doping. Tetragonalitas sampel tanpa doping 1,00910, sampel dengan doping Y3+ 0,4 % 1,0083 dan doping Y3+ 0,6%1,00846. Karakterisasi relaksasi dipole menunjukkan adanya dipole granuler pada sampel yang didoping akibat adanya muatan ruang disamping dipole kisi.

SINTESIS DAN KARAKTERISASI MATERIAL FOTOKATALIS HETEROJUNCTION Bi4Ti3O12/SrTiO3 DENGAN METODE SONIKASI Annisa Nur Illahi; Usman Ali Rouf; Hasal Maulidianingtyas; Erna Hastuti; Anton Prasetyo; Vina Nurul Istighfarini
Jurnal Kimia Riset Vol. 5 No. 1 (2020): Juni
Publisher : Universitas Airlangga

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20473/jkr.v5i1.20196

Bi4Ti3O12 dan SrTiO3 merupakan material semikonduktor yang berpeluang untuk digunakan sebagai fotokatalis. Namun, kedua material tersebut memiliki kekurangan karena hanya mampu bekerja pada daerah sinar UV dan memiliki laju rekombinasi yang cepat. Pembuatan material heterojunction merupakan salah satu upaya untuk mengatasi masalah ini. Riset ini bertujuan untuk mempelajari sifat fotokatalitik komposit Bi4Ti3O12/SrTiO3 yang disintesis dengan metode sonikasi. Hasil penelitian menunjukkan bahwa Bi4Ti3O12/SrTiO3 berhasil disintesis tanpa adanya pengotor. Mikrograf SEM menunjukkan bahwa Bi4Ti3O12 berbentuk plate-like sedangkan SrTiO3 berbentuk irregular spheres. Data UV-Vis DRS menunjukkan bahwa nilai energi celah pita Bi4Ti3O12/SrTiO3 dengan perbandingan mol (1/1), (1/2), (1/4), dan (1/6) berturut-turut adalah 3,178; 3,70; 3,137, dan 3,160 eV.

Monitoring Profil Berkas Elektron Menggunakan Sensor Chatode Ray Tube Fajar Fanani; Farid Samsu Hananto; Erna Hastuti
Jurnal Health Sains Vol. 1 No. 2 (2020): Jurnal Health Sains
Publisher : Syntax Corporation Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.46799/jhs.v1i2.24

Telah dilakukan rancang bangun monitoring profil berkas elektron menggunakan chatode ray tube menggunakan metode bahan pendar. Variasi tegangan inputan dilakukan pada 203 V, 205 V, 208 V, 210 V, 212 V, 213 V, 215 V, 218 V dan 220 V. Tegangan inputan mempengaruhi perubahan pada diameter, intensitas iluminasi dan dosis serap berkas elektron yang ditunjukkan hasil pengukuran pada nilai diameter dan intensitas ilumninasi berkas elektron yang berbanding lurus dengan kenaikan tegangan input. Sedangkan hasil pengukuran nilai dosis serap berkas elektron terjadi kenaikan pada variabel tegangan 203 V hingga 210 V dan mengalami penurunan pada tegangan 212 V, Kemudian mengalami kenaikan yakni semakin tinggi tegangan inputan, semakin besar pula nilai dosis serap berkas elektron. Hasil akurasi data pengukuran nilai dosis serap berkas elektron pada cathode ray tube dengan data SNI radiasi untuk pengawetan bahan makanan, yaitu pada variabel tegangan 208 Volt, 215 Volt dan 220 Volt memenuhi syarat untuk radiasi pengawetan makanan, diantaranya dapat digunakan untuk menghambat pertunasan selama penyimpanan pada umbi lapis dan umbi akar, menunda pematangan dan memperpanjang masa simpan pada sayur dan buah segar selain umbi lapis dan umbi bakar. Dan terakhir, digunakan untuk perlakuan karantina dan membasmi serangga.

Uji Degradasi Pewarna Rhodamine B oleh Senyawa Aurivillius Lapis Dua SrBi2Ta2O9 Usman Ali Rouf; Erna Hastuti; Anton Prasetyo
Jurnal Kartika Kimia Vol 4 No 1 (2021): Jurnal Kartika Kimia
Publisher : Department of Chemistry, Faculty of Sciences and Informatics, University of Jenderal Achmad Yani

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26874/jkk.v4i1.76

Senyawa Aurivillius lapis dua SrBi2Ta2O9 dilaporkan berpotensi sebagai material fotokatalis sehingga dapat digunakan untuk mendegradasi limbah zat warna. Pada penelitian ini telah disintesis senyawa SrBi2Ta2O9 dengan metode reaksi keadaan padatan dan selanjutnya dilakukan uji kemampuan dalam mendegradasi zat warna rhodamine B. Difraktogram menunjukkan bahwa, telah terbentuk senyawa SrBi2Ta2O9 dengan grup ruang A21am dan tidak ditemukan adanya pengotor. Gambar scanning electron microscopy (SEM) menunjukkan bahwa partikel SrBi2Ta2O9 berbentuk plate-like dan teraglomerasi. Spektrum diffuse reflectance spectroscopy menunjukkan bahwa SrBi2Ta2O9 mempunyai energi celah pita sebesar 3,15 eV (~393,60 nm). Hasil uji degradasi larutan rhodamine B menunjukkan bahwa kemampuan SrBi2Ta2O9 dalam mendegradasi adalah 8,6% selama 80 menit. Kemampuan degradasi yang rendah dikarenakan ukuran partikel SrBi2Ta2O9 relatif besar dan dalam keadaan teraglomerasi. Kata kunci: aglomerasi, fotokatalis, rhodamine B, SrBi2Ta2O9, ukuran partikel.

Pengaruh Konsentrasi HCl Pada Proses Exfoliasi Graphene Oxide/Reduce Graphene Oxide (GO/rGO) Dari Karbon Bulu Ayam Erna Hastuti; Feny Fefiyanti; Muthmainnah muthmainnah
INDONESIAN JOURNAL OF APPLIED PHYSICS Vol 12, No 2 (2022): October
Publisher : Department of Physics, Sebelas Maret University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.13057/ijap.v12i2.56282

An increase in the consumption of chicken meat may have an impact on the waste of chicken feathers. Several efforts have been made to treat chicken feather waste, which is difficult to decompose and can pollute the environment. Chicken feathers are biomass with a high keratin content that has the potential to be used as a carbon material. In this study, chicken feathers were used in the chemical exfoliation method to produce reduced Graphene Oxide (rGO) material. Chicken feathers are heated in two stages, at temperatures of 250 and 400 ℃ in the air. The exfoliation procedure was carried out with varying concentrations of HCl (0, 0.5, 1, 1.5, and 2 M). The X-ray diffraction spectra revealed that the sample had a rGO type carbon phase, with the crystal size decreasing as the HCl concentration increased. The presence of functional groups C-O, C=C, and C-OH identified as GO/rGO was revealed by FTIR spectra. The HCl exfoliation process reduced the sample's conductivity and capacitance, with the highest values obtained in aquadest sample (GO-0 M), about 10-5 S/m and 10-7 F/m2.

Nitrogen-doped Carbon Dots Derived from Green Algae and Ammonia as Photocatalyst Material Erna Hastuti; Mutiara; Kurniati; Hikmah
Jurnal Sains Materi Indonesia Vol. 25 No. 2 (2024): Jurnal Sains dan Materi Indonesia
Publisher : BRIN Publishing (Penerbit BRIN)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55981/jsmi.2024.2552

Carbon dots are a novel carbon-based material with the appealing properties of inexpensive nanomaterials, low toxicity, environmental tolerance, abundance, photostability, and simplicity of synthesis. Carbon dots (CDs) have effectively distinguished themselves from other materials due to their superior properties, such as ultra-small size, good photostability, excellent biocompatibility, and tunable fluorescence properties. This study synthesized carbon dots from green algae using a hydrothermal method at 180 °C and doped with nitrogen. Green algae contain carbohydrates, proteins, and poly-unsaturated fatty acids, allowing them to produce more carbon and be used as a precursor in synthesizing carbon dots. The FT-IR and UV-Vis spectra reveal the distinct functionalization and energy gap between the surface states of CDs and N-CDs. The carbon nanoparticles were then used as photocatalysts to degrade methyl red. The results indicate that nitrogen doping is superior for reducing methyl red and has tremendous potential for environmental applications.

Crystal Structure Parameter Analysis of Reduced Graphene Oxide (rGO) from Coconut Shell Charcoal Hikmah, Utiya; Azizah, Aghea Tahta Wahyu; Hastuti, Erna
Jurnal Fisika Flux: Jurnal Ilmiah Fisika FMIPA Universitas Lambung Mangkurat Vol 21, No 2 (2024): Jurnal Fisika Flux: Jurnal Ilmiah Fisika FMIPA Universitas Lambung Mangkurat
Publisher : Lambung Mangkurat University Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20527/flux.v21i2.17135

In this research, reduced graphene oxide (rGO) material from coconut shell charcoal was synthesized using the modified Hummer method. The reduction process of Graphene Oxide (GO) to rGO uses the reducing agent L-Ascorbic Acid (LAA) and is assisted by microwave radiation. The samples obtained were then characterized using XRD to analyze the crystal structure parameters of the rGO samples obtained. Based on the XRD results, the data obtained was then analyzed using the Scherrer and modified Scherrer equations to determine the crystal size in the sample. In addition, the Williamson-Hall equation is also used to analyze crystal size and lattice strain. This article also analyzes XRD data using the Rietveld method using Rietica software. The output from the Rietica software obtained lattice parameter values a ≠ b ≠ c and angle α = β = γ = 90° which indicates an orthorhombic crystal lattice structure. In the refinement process, Rietica's software affects the suitability parameters in the form of R and GOF indicator values. The sample obtained was also measured for the electrical conductivity value of the rGO sample using an LCR meter.

Molten Salt Synthesis of Photocatalyst Material SrBi4Ti4O15 for Methylene Blue Degradation al-Abror, Muhammad Lathif; Hastuti, Erna; Prasetyo, Anton
Jurnal Rekayasa Kimia & Lingkungan Vol 17, No 2 (2022): Jurnal Rekayasa Kimia & Lingkungan (December, 2022)
Publisher : Chemical Engineering Department, Syiah Kuala University, Banda Aceh, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23955/rkl.v17i2.25288

The four-layered Aurivillius SrBi4Ti4O15 compound has been reported to be potentially used as a photocatalyst material. In this research, SrBi4Ti4O15 was prepared by the molten salt method using NaCl/KCl and then used to degrade methylene blue. The analysis of sample diffractogram indicated that the SrBi4Ti4O15 was obtained but there was still the impurities of Bi4Ti3O12. The micrograph showed that particle shape of SrBi4Ti4O15 is plate-like (sheets) with a lot of agglomeration. The band gap energy of SrBi4Ti4O15 is 3.14 eV (394.85 nm), according to the Kubelka-Munk calculation from the spectrum of reflectance. The photocatalytic test results showed that SrBi4Ti4O15 degraded methylene blue to 47.8% in 120 minutes.

Nitrogen-doped Carbon Dots Derived from Green Algae and Ammonia as Photocatalyst Material Erna Hastuti; Mutiara; Kurniati; Hikmah
Jurnal Sains Materi Indonesia Vol. 25 No. 2 (2024): Jurnal Sains dan Materi Indonesia
Publisher : BRIN Publishing (Penerbit BRIN)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55981/jsmi.2024.2552

Carbon dots are a novel carbon-based material with the appealing properties of inexpensive nanomaterials, low toxicity, environmental tolerance, abundance, photostability, and simplicity of synthesis. Carbon dots (CDs) have effectively distinguished themselves from other materials due to their superior properties, such as ultra-small size, good photostability, excellent biocompatibility, and tunable fluorescence properties. This study synthesized carbon dots from green algae using a hydrothermal method at 180 °C and doped with nitrogen. Green algae contain carbohydrates, proteins, and poly-unsaturated fatty acids, allowing them to produce more carbon and be used as a precursor in synthesizing carbon dots. The FT-IR and UV-Vis spectra reveal the distinct functionalization and energy gap between the surface states of CDs and N-CDs. The carbon nanoparticles were then used as photocatalysts to degrade methyl red. The results indicate that nitrogen doping is superior for reducing methyl red and has tremendous potential for environmental applications.

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