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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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Degradation of Methylene Blue Using Cadmium Sulfide Photoanode in Photofuel Cell System with Variation of Electrolytes Gunawan Gunawan; Abdul Haris; Didik Setiyo Widodo; Linda Suyati; Wilman Septina
Indonesian Journal of Chemistry Vol 21, No 1 (2021)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.53131

Methylene blue degradation carried out using cadmium sulfide (CdS) photoanode in photofuel cell (PFC) had been done. CdS synthesized by chemical bath deposition (CBD) on the FTO substrate was used as anode and platinum as a cathode in photoelectrochemical studies. Characterization of CdS thin film was done using EDX, XRD, SEM, Raman, UV-Vis absorption spectrophotometer as well as photocurrent test of the CdS thin film under illumination using potentiostat with the three-electrode system. The EDX result indicated the presence of CdS with an elemental composition of Cd rich. XRD showed the appearance of CdS crystals in cubic and hexagonal formations. SEM image of CdS gave results in the form of crystals of less than 1 mm. Raman spectrum showed the appearance of CdS peaks. The bandgap of CdS was estimated to be 2.38 eV, and the photocurrent test confirmed that the film had a property of n-type semiconductor. Application of CdS thin film as a photoanode in the PFC system using 100 mg/L methylene blue solution showed degradation up to 48% for 2.5 h using a 4 cm2 photoanode, and the maximum potential of 0.8 V was obtained with a photoanode area of 1 cm2.

Synthesis, Characterization, and Study of Proton Exchange Polymer Membrane Properties of Sulfonated Copolymer Eugenol-diallyl Phthalate Ngadiwiyana Ngadiwiyana; Nor Basid Adiwibawa Prasetya; Gunawan Gunawan; Tutuk Djoko Kusworo; Heru Susanto
Indonesian Journal of Chemistry Vol 21, No 1 (2021)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.55353

Synthesis biopolymer of sulfonated copolymer eugenol-diallyl phthalate (PEGDAF), its characterization, and study of proton exchange polymer membrane properties had been done. This synthesis was conducted by eugenol and diallyl phthalate reaction to form PEGDAF, which is sulfonated using sulfuric acid. In addition, the functional groups of the PEGDAF and its sulfonated form were analyzed using FT-IR. Furthermore, the polymer properties were determined by measuring values of sulfonation degree, cation exchange capacity, proton conductivity, and water uptake. FT-IR spectra showed that the vinyl group had been added to the process of PEGDAF formation, while spectra deconvolution was used to confirm the occurrence of sulfonation reaction. The sulfonation of PEGDAF in 2 h optimum reaction time produces a black solid with a melting point of 133 °C in 16.55% yield. The highest proton conductivity, cation exchange capacity (CEC), and water uptake were 8.334 × 10–6 S cm–1, 0.44 meq/g, and 73.0%, respectively.

Synthesis of Graphite Paste/Molecularly Imprinted Polymer (MIP) Electrodes Based on Polyeugenol as a Glucose Sensor with Potentiometric Method Muhammad Cholid Djunaidi; Mei Dian Risda Afriani; Gunawan Gunawan; Miratul Khasanah
Indonesian Journal of Chemistry Vol 21, No 4 (2021)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.58964

Diabetes mellitus is a chronic disease in which the body is unable to metabolize carbohydrates, fats, and proteins. In this study, eugenol was polymerized and then contacted with glucose and crosslinked using polyethylene glycol diglycidyl ether (PEGDE). The resulted PE-Glucose-PEGDE was eluted using ethanol to form MIP-Glucose. It was then characterized by FTIR, SEM, electrodes using the Eutech 510 potentiostat and UV-Vis spectrophotometer. The result of polyeugenol synthesis is a reddish-brown powder with a yield of 99.90% and a molecular weight of 6318.033 g/mol. UV-Vis spectrophotometer analysis showed that the contacted glucose was 2152.505 ppm. SEM results showed differences in the surface morphology of the material, indicating the formation of cavities in MIP and ESM, while no cavities are found in NIP and ESN. The electrode optimization resulted in the best composition ratio of MIP 1 mol: paraffin: graphite, respectively of 20:35:45. The resulting electrode has a Nernst factor of 20.24 mV/decade with a measurement range of 10–5–10–1 M, a limit of detection value of 8.363 × 10–5 M, and the value of the selectivity coefficient (Kij) of the electrodes in a (10–5–10–1) M fructose solution was 0.3733; 0.23048; 0.17864; 0.12359; 0.1073.

Ferrate(VI) Synthesis Using Fe(OH)3 from Waste Iron Electrolysis and Its Application for the Removal of Metal Ions and Anions in Water Gunawan Gunawan; Abdul Haris; Nor Basid Adiwibawa Prasetya; Eka Pratista; Azis Amrullah
Indonesian Journal of Chemistry Vol 21, No 6 (2021)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.64824

Ferrate(VI) salt is an effective oxidant and coagulant for water treatment and removal of metal ions. This study demonstrates a new approach to processing metal ions and anions in water by Fe(VI) through Fe(III) obtained from the electrolysis of waste iron transformer. The electrolysis was successfully carried out in the Na2SO4 electrolyte using waste iron and zinc plates as anode and cathode, respectively. Fe(III) electrolysis results through the characterization of FTIR and XRD indicate compliance with Fe(OH)3 standards. Synthesis of ferrate was carried out by adding Fe(III) from electrolysis with NaOCl in alkaline conditions. The formed ferrate solution shows a purple color with a typical maximum wavelength of 505 nm. Furthermore, the ferrate obtained is used to remove metal ions (Fe(III), Cu(II), Zn(II), Mg(II), Pb(II)) and anions (sulfate, nitrate, and carbonate) in water with pH variations. Ferrate treatment filtrate was analyzed using AAS for metal ions, while sulfate, nitrate, and carbonate anions used UV-Vis spectrophotometry, turbidimetry, and titration methods. The results showed that ferrate effectively eliminates metal ions and anions in water with optimum pH 6. The mechanism of heavy metal removal by ferrate(VI) can be explained by ionic bonding and adsorption.

Removal of Methylene Blue Using Used Paper Powder Ghina Labiebah; Gunawan Gunawan; Muhammad Cholid Djunaidi; Abdul Haris; Didik Setiyo Widodo
Jurnal Kimia Sains dan Aplikasi Vol 22, No 1 (2019): volume 22 Issue 1 Year 2019
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Methylene blue removal by adsorption method had been done in batch method using adsorbent of used paper powder. Adsorption parameters covering adsorbent doses, contact times, pH, adsorbate concentrations and adsorption isotherm as well as desorption study of the absorbed methylene blue were evaluated. The results showed the highest adsorption of methylene blue was obtained at an optimum adsorbent dose, for 30 min at pH > 9. The maximum adsorption capacity of 30.77 mg/g was obtained with Langmuir isotherm model. While the effective methylene blue desorption on the used paper powder adsorbent was obtained c.a. 0.27 mg/g at pH 1.

Ekstraksi Campuran Logam Berat dan Pemisahan Cr(VI) dari Cr(III) Menggunakan Teknik Membran Cair Berpendukung (SLM) Muhammad Cholid Djunaidi; Abdul Haris; Gunawan Gunawan
Jurnal Kimia Sains dan Aplikasi Vol 5, No 3 (2002): Volume 5 Issue 3 Year 2002
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Telah dilakukan penelitian tentang transport logam berat menggunakan SLM dengan senyawa pembawa. Pengukuran pH memperlihatkan ion hidrogen terlibat dalam transport ini. Penentuan konsentrasi logam berat menggunakan AAS dan spektrofotometer UV-Vis menunjukkan bahwa dalam larytan campuran, transport optimum logam berat dalam fasa penerima diperoleh dengan pembawa campuran 1:4 (TBP:D2EHPA 1M) dan pemisahan Cr(VI) dari Cr(III) dapat dilakukan dengan pembawa tunggal. Urutan transport logam berat dengan pembawa campuran 1:4 (TBP:D2EHPA) tersebut dalam larutan campuran dan limbah laboratorium adalah tCu(II) > tFe(III) > tNi(II. Pada pemisahan Cr dalam limbah penyamakan kulit, TBP dapat mengekstrak Cr(III) dan Cr(VI) sementara D2EHPA hanya mengekstrak Cr(III) sehingga Cr(III) dan Cr(VI) dapat dipisahkan

Preparation of thin layer CuO from Cu2O using the Spin Coating Method at Various Annealing Temperature and Number of Dripping for Photoelectrochemical Water Splitting Eka Pratista; Gunawan Gunawan; Didik Setiyo Widodo
Jurnal Kimia Sains dan Aplikasi Vol 23, No 11 (2020): Volume 23 Issue 11 Year 2020
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

A thin layer preparation of CuO from Cu2O powder using Fehling's solution for photoelectrochemical applications has been performed. The research was focused on studying the effect of annealing temperature and the number of drops on the performance of CuO thin layer semiconductors from Cu2O powder prepared by spin coating with a rotation rate of 500 rpm for 15 seconds. The thin layers were treated with annealing with temperature variations of 300°C, 400°C, and 500°C for 1 hour and variations in the number of drops of 10, 20, and 50 drops. The CuO thin layer was tested in a photoelectrochemical process as a photocathode to split water with a simulated light of 1.5 AM (100 mW/cm2). The process of splitting water as a method of producing hydrogen energy by photoelectrochemistry is assisted by semiconductors, such as CuO, in an electrolyte solution to capture photons and drive the water-splitting reactions. Copper (II) Oxide (CuO) is a p-type semiconductor with a band gap of 1.2-2.5 eV, which can be used as a photocathode. The optimum photoelectrochemical measurement results were obtained at an annealing temperature of 400°C and 50 drops with a current density of 0.584 mA/cm2 at a potential of 0.2 V versus the Reversible Hydrogen Electrode (RHE). The results of the Scanning Electron Microscopy (SEM) analysis show that the morphology of the oxide is spherical. Energy dispersive X-ray (EDX) analysis displays that the sample contained 51.46% and 48.54% of Cu and O, respectively. The X-ray diffraction pattern (XRD) analysis shows that the oxide grain size is 44.137 nm.

Pemulihan (Recovery) dan Pemisahan Selektif Logam Berat (Zn, Cu dan Ni) dengan Pengemban Sinergi Menggunakan Teknik SLM Muhammad Cholid Djunaidi; Mudji Triatmo Melkias Aloysius; Gunawan Gunawan
Jurnal Kimia Sains dan Aplikasi Vol 6, No 3 (2003): Volume 6 Issue 3 Year 2003
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Telah dilakukan pemisahan logam berat (Zn Cu, Ni) dengan menggunakan pengemban/pembawa sinergi yaitu campuran TBP (tributil fosfat) dan D2EHPA (asam di-2 etil heksil fosfat) dengan perbandingan 1:4 (1 M) dalam alat pemisahan SLM selama 4 jam. Analisa dilakukan dengan mengukur konsentrasi logam di fasa umpan dan penerima menggunakan AAS dan konsentrasi ion hidrogen menggunakan pH meter. Hasil analisa disimpulkan bahwa transport logam dari fasa umpan ke fasa penerima dipengaruhi oleh konsentrasi ion hidrogen (pH) dan ion tanding. Transport sangat dipengaruhi oleh selektifitas pengemban/pembawa terhadap masing-masing logam. Pengemban TBP: D2EHPA 1:4 (1 M) cukup selektif untuk pemisahan logam berat dari limbahnya dengan urutan selektifitas adalah sebagai berikut : Zn>Cu>>Ni.

Metode Elektrokoagulasi Sistem Fe(S)| Cd(II)(aq), NaCl(aq) || H2O(l)|C untuk Pengambilan Kadmium(II) Nabila Nurdiantika; Linda Suyati; Gunawan Gunawan
Greensphere: Journal of Environmental Chemistry Vol 1, No 1 (2021): Volume 1 Issue 1 tahun 2021
Publisher : Universitas Diponegoro

Telah dilakukan penelitian mengenai metode elektrokoagulasi sistem Fe | Cd(II), NaCl || H2O | C untuk pengambilan Cd(II). Besi hidroksi hasil elektrolisis adalah agen koagulasi yang sangat baik. Tujuan dari penelitian ini menentukan kondisi optimum dalam proses pengambilan Cd(II) membandingkan elektrokoagulasi dengan koagulasi, mengetahui morfologi permukaan elektroda besi sebelum dan sesudah elektrokoagulasi, serta menentukan kinetika elektrokoagulasi pengambilan Cd(II). Beberapa kondisi proses elektrokoagulasi yang divariasikan meliputi pengaruh rapat arus, konsentrasi awal Cd(II), pH larutan, dan waktu proses elektrokoagulasi. Analisis konsentrasi Cd(II) setelah proses elektrokoagulasi menggunakan instrumen Spektrofotometer Serapan Atom (SSA) dan karakterisasi permukaan eletroda besi dengan SEM. Hasil penelitian menunjukkan pengambilan Cd(II) dicapai pada rapat arus 36 µA/cm2, konsentrasi awal Cd(II) 9 mg/L, pH larutan 7, dan waktu proses elektrokoagulasi selama 120 menit dengan hasil yang dicapai sebesar 99,5%. Pengambilan Cd(II) lebih efektif dengan metode elektrokoagulasi dibandingkan dengan metode koagulasi. Morfologi permukaan besi yang semula tampak halus setelah proses elektrokoagualasi menjadi kasar akibat adanya sebagian besi di permukaan elektroda yang larut dalam produksi besi hidroksida. Kinetika elektrokoagulasi pengambilan Cd(II) mengikuti reaksi pseudo orde dua, dengan k = 17,80 x 10-2 g.mg-1menit-1.Kata Kunci: Elektrokoagulasi, Pengambilan Cd(II), Fe(OH)3.

The Effect of Cu Ohmic Contact on Photoelectrochemical Property of S-CuO Thin Film Photocathodes Aziz Amrullah; Gunawan Gunawan; Nor Basid Adiwibawa Prasetya
Jurnal Kimia Sains dan Aplikasi Vol 22, No 6 (2019): Volume 22 Issue 6 Year 2019
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

The development of semiconductor materials as photocathodes that have excellent performance is significant for the photoelectrochemical reaction of hydrogen evolution. The thin film of sulfur-doped Copper (II) oxide (S-CuO) was successfully synthesized using the cyclic voltammetry method. Investigation of photoelectrochemical properties of S-CuO photocathodes, including current density, onset potential, applied photon to current efficiency (ABPE), and bandgap had been carried out. It was reported that the Cu ohmic contact affected the photoelectrochemical properties and the stability of the thin film. The presence of Cu ohmic contact can improve the performance of S-CuO thin film photocathodes. The S-CuO TU 20 mM thin film has the best response with a current density of -0.923 mA/cm2, an onset potential of 0.59 V, and ABPE of 0.21%. Stability occurred at pH 7 in 0.2M NaH2PO4. The optical analysis showed S-CuO TU 20 mM bandgap of 1.7 eV.

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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