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All Journal JURNAL KIMIA SAINS DAN APLIKASI Jurnal Ilmu Kimia Universitas Brawijaya Physics Student Journal Natural B The Journal of Pure and Applied Chemistry Research JURNAL INTEGRASI PROSES Jurnal Kimia dan Kemasan Journal of Geoscience, Engineering, Environment, and Technology Chimica et Natura Acta Molekul: Jurnal Ilmiah Kimia JKPK (Jurnal Kimia dan Pendidikan Kimia) JPPM (Jurnal Pengabdian dan Pemberdayaan Masyarakat) Fullerene Journal of Chemistry Acta Chimica Asiana Jurnal Kimia dan Kemasan ARRUS Journal of Engineering and Technology Makara Journal of Science Indonesian Journal of Fundamental Sciences Indonesian Mining Journal
Rachmat Triandi Tjahjanto
Chemistry Department, Faculty Of Mathematics And Natural Sciences, University Of Brawijaya, Jl. Veteran 65145 Malang, Indonesia
Agriculture, Biological Sciences & Forestry Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Civil Engineering, Building, Construction & Architecture Computer Science & IT Earth & Planetary Sciences Electrical & Electronics Engineering Energy Engineering Environmental Science Immunology & microbiology Industrial & Manufacturing Engineering Library & Information Science Materials Science & Nanotechnology Mechanical Engineering Medicine & Pharmacology Physics Public Health Social Sciences Other

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Extraction of Manganese Ore from East Nusa Tenggara-Indonesia for Production of Mn(II)-Terephthalate and Mn(II)-Tartrate Coordination Polymers Abi, Faustina De Yesu Prisila; Tjahjanto, Rachmat Triandi; Prananto, Yuniar Ponco
Journal of Geoscience, Engineering, Environment, and Technology Vol. 10 No. 02 (2025): JGEET Vol 10 No 02 : June (2025)
Publisher : UIR PRESS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25299/jgeet.2025.10.02.21556

Abstract

Pyrolusite, a manganese ore from East Nusa Tenggara (Indonesia), was explored and utilized in the production of crystalline Mn(II) based coordination polymers materials, namely Mn(II)-terephthalate and Mn(II)-tartrate. The pyrolusite was extracted into Mn(II) sulfate by acid method in the presence of hydrogen peroxide. The Mn(II) sulfate, characterized by X-ray fluorescence (XRF), infrared spectroscopy (IR), and X-ray powder diffraction (PXRD), was then used as a precursor in the production of crystalline Mn(II) based coordination polymers materials using a solution method at room temperature. Two ligands, terephthalate and tartrate, were used separately, in which the terephthalate complex was prepared using a layered solution technique, while the tartrate complex was made using a direct mixing technique. The synthesized Mn(II) coordination polymers were then characterized by FTIR and PXRD. This study finds that the manganese ore was extracted as MnSO4 compounds with purity of 96.88% and average crystallite size of 103 nm. The MnSO4 was successfully converted into crystalline Mn(II) coordination polymers materials. Based on IR and PXRD analyses, the crystalline products were identified as Mn(II)-aqua-terephthalato and Mn(II)-aqua-tartrato hydrate complexes, in which the former complex display 3D networks and the latter complex display 2D sheets of polymeric structures.
The Influence of Fe and Cr Dopant in the Synthesis of Ca3Co4O9 Thermoelectric Material on Crystal Structure, Crystal Size, Thermal Conductivity, and Electrical Conductivity Rahman, Imam Syafrudin; Tjahjanto, Rachmat Triandi; Masruroh, Masruroh
JKPK (Jurnal Kimia dan Pendidikan Kimia) Vol 9, No 3 (2024): JKPK (Jurnal Kimia dan Pendidikan Kimia)
Publisher : Program Studi Pendidikan Kimia FKIP Universitas Sebelas Maret

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/jkpk.v9i3.93818

Abstract

In this work, we study, by sol-gel method, CCO doped with Fe and Cr dopants, the implications for the aspects, crystal structure, crystal size, thermal conductivity, and electrical conductivity. Nevertheless, CCO has low thermoelectric efficiency and thus still longs for optimization in response to the performance, stability, and ecological environment requirement, which needs improvement. Dope would enhance the concentration of charge carriers without modifying the material structure itself. X-ray diffraction (XRD) to characterize the crystal structure and the Williamson–Hall (WH) method to calculate the crystal size were performed. SEM-EDS analyses provide surface morphology, particle size distribution, and elemental composition. The results show that the dopants change, among others, crystal size, microstrain, crystallinity index, and thermal and electrical conductivity, but no change in the crystal structure itself for any of these dopants. Fe doping increased the crystal size of CCO to 144.816 nm (versus 143.382 nm for pure CCO). Compared to Cr doping, the crystal's size was reduced to 65.232 nm. Where the estimated thermal conductivity increased for both dopants, attaining a value of 1.985967 W/mK for CCO-Fe and 1.952233 W/mK for CCO-Cr, concerning the value of 1.740633 W/mK of undoped CCO. Electrical conductivity also expanded (14.50 S/cm for CCO; 14.67 S/cm for CCO-Fe; 14.83 S/cm for CCO-Cr). These improvements highlight the potency of Fe and Cr dopants to fine-tune the CCO for thermoelectric usage.
Co-Authors A.A. Ketut Agung Cahyawan W Abd. Rahman Abdul Rahman Afida, Laely Nur Agus Farid Fadli Agustina Mogi Ahmad Fudhail  Majid Ahmad Naufal Hasti Eka Putra Akhmad Sabarudin Alfina, Bulan Tahta Alfita Safitri Andi Nafis An Naafi Angga Fami Rayendra Anggriana Novitasari, Anggriana Ani Mulyasuryani Anjani, Ryzki Martha Anna Safitri Ardhi, Tunjung Nourman Sasono Asrianda Asrianda Barlah Rumhayati Barlah Rumhayati Christiana Adi Damayanti Danar Purwonughroho Danar Purwonugroho Danar Purwonugroho Darjito Darjito Darjito, Darjito Dhesy Galuh R. Dhesy Galuh Ratnawati Diah Mardiana Diana Eka Pratiwi Diana Eka Pratiwi Didik Pramana Dita Anggarini Eko Waluyo Elvina Dhiaul Iftitah Elvina Dhiaul Iftitah Elvina Dhiaul Iftitah Erica Marista Rosida Ernesta Wae Faisal Maulana Malik Ibrahim Faustina De Yesu Prisila Abi Finisia, Yenni Herinda Sensustania Hidayat, Rusdhi Nur I Wayan Adi Suarya I Wayan Wira Yuda Iftitah, Elvina Dhiaul Ika Oktavia Wulandari Imam Fathoni Isnaini, Yulia Nur Johnson N Naat Khoirun Nisyak Khoirun Nisyak Kiky Frederika Rumapar Lapailaka, Titus Layta Dinira Lidya Rosnita Masruroh Masruroh Masruroh Masruroh Masruroh Masruroh Masruroh MASRUROH Masruroh Masruroh Masruroh Masruroh Meirawati, Dian Mohammad Abdul Ghofur Mohammad Farid Rahman Mohammad Misbah Khunur Muchammad Zainul Anwar Muhammad Misbah Khunur Muhlis Muhlis Nafikah, Fifi Nik Matul Ula Nisyak, Khoirun Oktaria Ardika Pratama, Oky Yoga Purwonugroho, Danar Rahman, Imam Syafrudin Rendrahadi, Randhy Dwi Riska Yudhistia Asworo Rizky Arief Shobirin Roosdiana, Anna Rosmawati, Angelina Rosyida, Firdania Firdaus S.J. Iswarin Siti Mariyah Ulfa Sri Wardhani Suriati Eka Putri Ulfa Andayani Ulfa Anggraini Uswatun Hasanah Utomo, Edi Priyo Vita Valiana Widyasari, Elok Nuri Yuniar Ponco Prananto Zaemi, Haris ZAINUL ABIDIN Zulfikar, Mochammad Abrianto