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All Journal BERKALA FISIKA JURNAL KIMIA SAINS DAN APLIKASI Bulletin of Chemical Reaction Engineering & Catalysis Jurnal Ilmiah Arena Tekstil Indonesian Journal of Chemistry Molekul: Jurnal Ilmiah Kimia Jurnal Pengabdian Kepada Masyarakat (JPKM) Tabikpun Greensphere: Journal of Environmental Chemistry Bulletin of Chemical Reaction Engineering & Catalysis

Gunawan Gunawan

Chemistry Department, Faculty Of Sciences And Mathematics, Diponegoro University Jl. Prof. Soedarto, SH., Tembalang, Semarang

Author-ID : 3060613

Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Computer Science & IT Education Engineering Health Professions Industrial & Manufacturing Engineering Physics

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Pengaruh pH pada Penurunan Kadar Ion Sianida secara Elektrokimia dengan Elektroda PbO2/Grafit Byan Pratama; Didik Setiyo Widodo; Gunawan Gunawan
Jurnal Kimia Sains dan Aplikasi Vol 15, No 3 (2012): Volume 15 Issue 3 Year 2012
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Telah dilakukan penelitian mengenai pengaruh pH pada penurunan kadar ion sianida secara elektrokimia dengan elektroda PbO2/grafit. Tujuan dari penelitian ini adalah menurunkan kadar sianida dengan metode elektrolisis menggunakan elektroda PbO2/grafit dan mengkaji pengaruh pH terhadap penurunan kadar sianida dalam limbah artificial dengan elektroda PbO2/grafit. Logam PbO2 digunakan sebagai anoda dan grafit sebagai katoda. Elektrolisis dilakukan selama 8 jam disertai pengadukan dan variasi pH dengan potensial aplikasi sebesar 5,0 volt. Variasi pH yang digunakan adalah 7, 8, 9, 10, 11, 12, dan 13 yang diatur dengan penambahan H2SO4 atau NaOH. Analisis sianida dilakukan secara kuantitatif dengan metode spoktrofotometri UV-Vis, sedangkan analisis karbonat dan amoniak dilakukan secara kualitatif. Hasil penelitian menunjukkan bahwa metode elektrolisis dengan elektroda PbO2/grafit mampu menurunkan kadar sianida sampai 100% dan pada pH basa penurunan kadar sianida cenderung meningkat dengan peningkatan pH. Elektrolisis larutan sianida menghasilkan karbonat dan amoniak.

Penggunaan Bunga Rosela (Hibiscus Sabdariffa) sebagai Zat Warna pada Dye Sensitized Solar Cell Retno Adi Mawarti; Abdul Haris; Gunawan Gunawan
Jurnal Kimia Sains dan Aplikasi Vol 13, No 3 (2010): Volume 13 Issue 3 Year 2010
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Telah dilakukan penelitian tentang performansi Dye Sensitized Solar Cell pada kaca LCD dengan sensitizer dari bunga rosela (Hibiscus sabdariffa). Konstruksi sel surya yang digunakan adalah sistem sandwich. Elektroda lawan-grafit diletakkan di atas lapisan TiO2–pewarna bunga rosela dengan elektrolit terletak di antara kedua elektroda tersebut. Karakterisasi sel surya dilakukan dengan analisis serapan elektronik pada bunga pacar air merah, Scanning Electron Microscopy (SEM), difraksi sinar X, serapan inframerah, dan pengukuran potensial sel surya. Panjang gelombang maksimum pada bunga rosela sebesar 515 nm. Morfologi permukaan lapis tipis TiO2 pada perbesaran 20.000x dan 40.000x menunjukkan permukaan TiO2 yang beronggga-rongga dengan ukuran yang berkisar antara 0,1 - 13 nm. Tampang lintang lapis tipis TiO2 menunjukkan lapis-lapis homogen dengan ketebalan 3 nm. Pada difraktrogram lapis tipis TiO2 menunjukkan intensitas pola difraksi cukup tinggi dengan puncak utama pada 2θ yaitu 25,41°; 37,91°; 48,16°; 55,19° dan 62,83° dengan jarak antar bidang (d) sebesar 3,503 Å; 2,371 Å; 1,888 Å; 1,663 Å dan 1,478 Å sebagai kristal anatase dengan ukuran kristal sebesar 17,366 nm. Penelitian sistem sel surya dengan rosela sebagai zat warna dengan variasi waktu perendaman yaitu 24 jam dan 1 jam masing-masing menghasilkan harga efisiensi sebesar 0,00065% dengan arus 0,035.10-3 A, tegangan 0,509 V serta 0,00022% dengan arus 0,028.10-3 A dan tegangan 0,293 V.

Decolorization of Artificial Waste Remazol Black B using Electrogenerated Reactive Spesies Didik Setiyo Widodo; Linda Suyati; Gunawan Gunawan; Abdul Haris
Jurnal Kimia Sains dan Aplikasi Vol 21, No 1 (2018): Volume 21 Issue 1 Year 2018
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Electrolysis method (electrodecolorization) coupled with ●OH radicals and chlorine generation has been performed in decolorizing of artificial waste of remazol black B (reactive black 5). The electrodecolorization as one of advanced oxidation process (AOP) shows its determinant potential in overcoming environmental problems due to dye contained waste as well as its green in desaign and efficiency. The project aim was to decolorize the RBB solution completely and effectively. The mission was completed by designing decolorizing reactor working with electrolytic system in tandem with electrogeneration of reactive species from HCl and NaCl electrolyte. Lead oxide, PbO2 was choosen as anode. The efficiency of decolorization process was comparated with those of Na2SO4 as electrolyte. Data of UV-Vis spectrometry, atomic absorption spectrophotometry and COD showed that the performance of electrolysis design was significantly enhanced with the reactive species generation process. Electrolysis of 100 mL sample of 200 mgL-1 RBB with reactive species generation was rearched almost two-fold faster in decolorizing the dye solution rather than in Na2SO4 one. The design rearchs more than 99 % in decoloriziation percentages, reducing COD more than 96 % indicating the potential and effectiveness of electroremediation process.

Pengaruh Substitusi Semen oleh Silika Abu Sekam Padi terhadap Kuat Tekan dan Suhu Reaksi Semen Portland Adi Darmawan; Dian Anggraini; Gunawan Gunawan
Jurnal Kimia Sains dan Aplikasi Vol 11, No 1 (2008): Volume 11 Issue 1 Year 2008
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Kebutuhan semen untuk bahan bangunan semakin meningkat, sehingga untuk meminimalisir penggunaan semen diperlukan agregat tambahan. Agregat tersebut adalah abu sekam padi yang di masyarakat belum dimanfaatkan secara optimal. Dengan penambahan abu sekam padi tersebut dapat memperbaiki kuat tekan dan suhu reaksi semen. Telah dilakukan penelitian pengaruh penambahan silika abu sekam padi terhadap kuat tekan dan suhu reaksi semen Portland. Penambahan silika abu sekam padi ke dalam semen Portland dilakukan dengan variasi komposisi silika abu sekam padi antara 0%-30% terhadap berat semen. Hasil penelitian menunjukkan bahwa kuat tekan semen dipengaruhi umur mortar dan komposisi silika. Mortar pada umur 7 hari memiliki kuat tekan yang lebih rendah daripada umur 28 hari. Kuat tekan meningkat antara 0-20% dan mengalami penurunan pada 20-30%. Kuat tekan yang paling optimal diperoleh pada penambahan silika abu sekam padi sebesar 3%, sedangkan suhu reaksi cenderung menurun dengan penambahan silika abu sekam padi.

Pemurnian Garam NaCl melalui Metode Rekristalisasi Garam Krosok dengan Penambahan Na2CO3, NaOH dan Polialuminium Klorida untuk Penghilangan Pengotor Ca2+ dan Mg2+ Akustika Gemati; Gunawan Gunawan; Khabibi Khabibi
Jurnal Kimia Sains dan Aplikasi Vol 16, No 2 (2013): Volume 16 Issue 2 Year 2013
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Telah dilakukan penelitian tentang pemurnian garam NaCl melalui metode rekristalisasi garam krosok dengan penambahan Na2CO3, NaOH dan polialuminium klorida untuk penghilangan pengotor Ca2+ dan Mg2+. Tujuan penelitian ini adalah untuk menentukan pengaruh penambahan Na2CO3 dan NaOH terhadap konsentrasi kadar Mg2+ dan Ca2+ pada garam krosok serta untuk mengetahui efektivitas penambahan flokulan polialuminium khlorida (PAC) dalam reaksi pengendapan CaCO3 dan Mg(OH)2 dengan metode rekristalisasi modifikasi spray. Metode yang dilakukan pada penelitian ini dengan cara menambahkan bahan pengikat pengotor yang harganya lebih murah seperti Na2CO3 dan NaOH serta flokulan PAC yang dapat mengendapkan ion pengotor pada garam yaitu ion Ca2+ dan Mg2+ kemudian dilakukan rekristalisasi dengan modifikasi model spray untuk mendapatkan kristal NaCl yang lebih murni dengan lahan yang tidak begitu luas dan rekristalisasi meja kristalisasi penguapan. Hasil pemurnian garam krosok diperoleh kadar NaCl 98,53%, Ca2+ 0,0600%, dan Mg2+ 0,0288% dengan penambahan Na2CO3 20% w, NaOH0,1 N dan PAC 10 ppm sebanyak 3 mL, yang telah sesuai standar industri Indonesia (SII).

Evaluation of Novel Integrated Dielectric Barrier Discharge Plasma as Ozone Generator Muhammad Nur; Ade Ika Susan; Zaenul Muhlisin; Fajar Arianto; Andi Wibowo Kinandana; Iis Nurhasanah; Sumariyah Sumariyah; Pratama Jujur Wibawa; Gunawan Gunawan; Anwar Usman
Bulletin of Chemical Reaction Engineering & Catalysis 2017: BCREC Volume 12 Issue 1 Year 2017 (April 2017)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.12.1.605.24-31

This paper presents a characterization of an integrated ozone generator constructed by seven of reactors of Dielectric Barrier Discharge Plasma (DBDP). DBDP a has spiral-cylindrical configuration. Silence plasma produced ozone inside the DBDP reactor was generated by AC-HV with voltage up to 25 kV and maximum frequency of 23 kHz. As a source of ozone, dry air was pumped into the generator and controlled by valves system and a flowmeter. We found ozone concentration increased with the applied voltage, but in contrary, the concentration decreased with the flow rate of dry air. It was also found that a maximum concentration was 20 mg/L and ozone capacity of 48 g/h with an input power of 1.4 kW. Moreover, in this generator, IP efficiency of 8.13 g/kWh was obtained at input power 0.45 kW and air flow rate of 9 L/min. Therefore, be the higher ozone capacity can be produced with higher input power; however, it provided lower IP efficiency. The effect of dry air flow rate and applied voltage on ozone concentrations have been studied. At last, spiral wire copper was very corrosive done to the interaction with ozone, and it is necessary to do a research for finding the best metals as an active electrode inside of the quartz dielectric.

Improving the Electrical Conductivity of the Composite Comprising Bismuth Oxide, Activated Carbon, and Graphite for Use as a Battery Anode Yayuk Astuti; Faradina Azahra Zaqia; Aulia Zahra Ekaningsih; Gunawan Gunawan; Adi Darmawan
Indonesian Journal of Chemistry Vol 23, No 6 (2023)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.74155

This research is concerned with the synthesis and characterization of a composite material that may be used as a battery electrode. Bismuth oxide (Bi2O3) was synthesized from Bi(NO3)3·5H2O, Na2SO4, and NaOH mixed with commercial activated carbon and graphite. The composite formation process was carried out using the hydrothermal method at 110 °C for 5 h. The characterization data indicated the composites produced contained Bi2O3 with a monoclinic crystal system, and Bi2O3 particles were evenly distributed in the composite. The composites were characterized to be mesoporous, with the electrical conductivity reaching 10−1 S m−1. The development of this composite material has potential applications in the field of energy storage, particularly in the development of battery anode.

Fabrikasi Dye-Sensitized Solar Cell Menggunakan Fotosensitizer Ekstrak Bunga Rosela (Hibiscus sabdariffa L) dan Elektrolit Padat Berbasis PEG (Polyethylene Glycol) Mustaqim Mustaqim; Abdul Haris; Gunawan Gunawan
Jurnal Kimia Sains dan Aplikasi Vol 20, No 2 (2017): Volume 20 Issue 2 Year 2017
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Telah dibuat Dye-Sensitized Solar Cell (DSSC) menggunakan dye alami ekstrak bunga Rosela dan elektrolit padat berbasis PEG yang mengandung pasangan redoks I-/I3-. Dye-Sensitized Solar Cell dikonstruksi dengan struktur sandwich menggunakan fotoelektrode TiO2 yang dideposisi pada kaca Transparent Conductive Oxide (TCO) dengan elektrode lawan grafit. Dye ekstrak bunga rosela dimaserasi dalam campuran metanol, asam asetat dan air selama 24 jam dan digunakan untuk perendaman fotoelektroda TiO2 selama 1 jam dan 24 jam. Dye dikarakterisasi menggunakan FT-IR dan UV-Vis dan TiO2 menggunakan X-RD dan SEM. Kinerja sel surya diuji di bawah sinar matahari selama 1 jam pada jam 12:15-13:15 dengan suhu atmosfir 39°C. Spektra UV-Vis dan FT-IR larutan dye menunjukkan adanya kandungan antosianin pada panjang gelombang maksimum 530 nm dan diperkuat dengan munculnya gugus hidroksil, benzena dan karbonil pada serapan inframerah. Hasil karakterisasi XRD dan SEM menunjukkan TiO2 memiliki fase kristalin anatase dengan ukuran kristal sebesar 41,56 nm dan morfologi permukaan dengan ukuran rongga sekitar 94,11nm dan ketebalan penampang lintang sekitar 39,05. Dye-Sensitized Solar Cell yang dibuat menghasilkan potensial rangkaian terbuka (VOC) sebesar 0,124 V dan 0,127 V , arus rangkaian pendek (ISC) 0,084 mA dan 1,275 mA, serta efisiensi 0,00098 % dan 0,01883 % masing-masing untuk perendaman fotoelektroda TiO2 1 jam dan 24 jam.

Synthesis, Characterization of Cu, S doped TiO2 and Its Photocatalytic Activity for Degradation of Remazol Black B Abdul Haris; Gunawan Gunawan; Didik Setiyo Widodo; Rahmad Nuryanto; Retno Ariadi Lusiana; Mei Viantikasari
Jurnal Kimia Sains dan Aplikasi Vol 22, No 2 (2019): Volume 22 Issue 2 Year 2019
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Copper and sulfur modified TiO2(Cu-S-TiO2) photocatalyst was successfully synthesized using TiCl4, Cu(NO3)2.3H2O and H2SO4 as precursors by the sol-gel method andcalcination at 450°C for 4 hours. The synthesized photocatalyst was characterized by X-Ray Diffraction (XRD), Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS), Diffuse Reflectance Spectroscopy (DRS), Brunauer Emmett Teller (BET) method. The XRD results showed that the Cu-S-TiO2 photocatalyst had an anatase phase with a crystal grain size of 17.54 nm. However, the SEM image of the modified TiO2 showed inhomogeneous phase due to the crystal clustering of imperfect homogenization during the synthesis and sintering processes. The patterns of EDSof Cu-S-TiO2depicted the elements of Ti, O, Cu and S with doping of Cu and S c.a. 7 and 1%, respectively. Analysis using DRS UV-Vis showed Cu-S-TiO2 was able to shift the absorption of the TiO2 photocatalyst wavelength to the visible region with a band energy gap of 1.9 eV. The BET analysis results showed that the specific surface area (SBET), pore volume (Vp) and average pore volume radius (Dp) were measured from large Cu-S-TiO2, therefore Cu-S-TiO2 had good physicochemical and photocatalytic properties. The photocatalytic activity of 0.1 g Cu-S-TiO2 with 15 Watt tungsten light irradiation for 4 h was able to degrade 50 mL remazol black B 10 mg/L c.a. 92.60 %.

Optimization of Chitosan-Carboxymethyl Chitosan Membrane Modification with PVA to Increase Creatinine and Urea Permeation Efficiency Riska Nurfirda Annisa; Retno Ariadi Lusiana; Gunawan Gunawan; Hasan Muhtar
Jurnal Kimia Sains dan Aplikasi Vol 27, No 4 (2024): Volume 27 Issue 4 Year 2024
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jksa.27.4.189-196

Polyvinyl alcohol (PVA) modified chitosan-carboxymethyl chitosan (CMC) membrane has been successfully fabricated and used as a dialysis membrane. This research aims to examine the manufacturing process, characterization, and dialysis performance of CMC and PVA-modified chitosan membranes. The membrane used the phase inversion method in acetic acid solvent with 5 CS:CMC: PVA dope compositions. Based on FTIR data, the modification process did not produce new spectra. Furthermore, the interaction produces a membrane with higher physical characteristics in terms of porosity, swelling, water uptake, hydrophilicity, and pH resistance values, which increase by 1.5–115%. Meanwhile, chitosan modification makes the membrane structure different from the original, requiring a longer degradation time. The modification also increased the permeation ability of urea by 17–65% and creatinine permeation by 20–62%. Membranes have the ability to be used more than once.

Co-Authors Abdul Haris Abdul Haris Abdul Haris Ade Ika Susan Adi Darmawan Akustika Gemati Aloysius, Mudji Triatmo Melkias Andi Wibowo Kinandana Andi Wibowo Kinandana Anwar Usman Aris Supriati Aulia Zahra Ekaningsih Azis Amrullah Aziz Amrullah Byan Pratama Desriana Chrisyanti Devi Maryani Dewi Anggia Murni Diah Lestari Pangestuti Dian Anggraini Didik Setiyo Widodo Doddy Bestyan Dyah Hari Setyaningrum Eka Pratista Eka Pratista Fajar Arianto Fajar Arianto Faradina Azahra Zaqia Ghina Labiebah Hasan Muhtar Heru Susanto Iis Nurhasanah Ira Fibriari khabibi Khabibi Khabibi Khabibi Kharisma Luthfiaratri Rahayu Linda Suyanti Linda Suyati Linda Suyati Mei Dian Risda Afriani Mei Viantikasari Miratul Khasanah Mohammad Munir Mudji Triatmo Melkias Aloysius Muhammad Cholid Djunaidi Muhammad Nur Muhammad Nur Muhammad Nur Muhammad Nur Mustaqim Mustaqim Nabila Nurdiantika Ngadiwiyana M.Si. S.Si. Noni Ika Rahmawati Nor Basid Adiwibawa Prasetya Nor Basid Adiwibawa Prasetya Nur Athikoh Pratama Jujur Wibawa Rahayu, Arianti Rahmad Nuryanto Retno Adi Mawarti Retno Ariadi Lusiana Riska Nurfirda Annisa Riyanti, Ani Dwi Rum Hastuti Sri Handayani Suhartana Suhartana Sumariyah Sumariyah Suryadi, Joko Tutuk Djoko Kusworo Wahyu Adi Kristanto Wilman Septina Yayuk Astuti Zaenul Muhlisin Zaenul Muhlisin

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