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All Journal CHEMISTRY PROGRESS JURNAL LPPM BIDANG SAINS DAN TEKNOLOGI Communications in Science and Technology
Bonaventura, Ridho
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Chemistry Education Engineering

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Adsorpsi Simultan Ion Cd(II) pada Abu Dasar Batubara Teraktivasi Anwar, Chairil; Wijaya, Dwi Putra; Munandar, Nurharis; Bonaventura, Ridho; Hutagalung, Fajar Y.S.T.
JURNAL LPPM BIDANG SAINS DAN TEKNOLOGI Vol. 9 No. 2 (2024): JLPPM SAINTEK
Publisher : Universitas Sam Ratulangi

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35801/jlppmsains.9.2.2024.60653

Abstract

Telah dilakukan penelitian tentang adsorpsi simultan ion Cd(II) menggunakan abu dasar batubara teraktivasi. Penelitian dilakukan dengan mengaktivasi abu dasar batubara menggunakan HCl pekat. Karakterisasi abu dasar batubara teraktivasi dilakukan dengan menggunakan spektrofotometer infra merah dan difraktometer sinar-X. Parameter yang dipelajari meliputi pengaruh pH dan variasi waktu konta. Mekanisme adsorpsi diketahui melalui desorpsi dengan menggunakan pelarut aquades dan KNO3. Konsentrasi ion logam yang tersisa setelah adsorpsi dan desorpsi ditentukan dengan menggunakan spektrofotometer serapan atom. Hasil karakterisasi menunjukkan bahwa abu dasar batubara teraktivasi telah terbentuk dengan baik. Kondisi optimum adsorpsi ion logam Cd(II) abu dasar batu bara teraktivasi adalah pH 5 dan waktu kontak 60 menit. Parameter kinetika adsorpsi abu dasar terakteraktivasi mengikuti persamaan kinetika pseudo orde dua dengan nilai konstanta laju pada ion Cd (II) 0,209 dan 1,734 g.mg-1.min-1. Model isoterm adsorpsi mengikuti model isoterm Langmuir dengan konstanta kesetimbangan sebesar 13125,6 L.mol-1. Kapasitas adsorpsi sebesar 1,0433 x 10-5 dan melibatkan energi adsorpsi sebesar 23,49. Mekanisme adsorpsi simultan ion Cd(II) dipengaruhi oleh berbagai interaksi yaitu: mekanisme pemerangkapan (28,26), mekanisme pertukaran ion (23,06).
Synthesis of Cu Nanoparticles using Anredera cordifolia Extract and their Potential as Antidiabetic with Alpha Amylase Enzyme Inhibition Munandar, Nurharis; Aritonang, Henry F.; Bonaventura, Ridho; Wijaya, Dwi Putra
Communications in Science and Technology Vol 10 No 2 (2025)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.10.2.2025.1829

Abstract

This study reports a green synthesis of copper nanoparticle using binahong (Anredera cordifolia) leaf extract as both a bioreductant and a capping agent. The synthesis was optimized by varying the extract-to-precursor ratio (1:3, v/v) and the reaction pH (6–11) with pH 10 selected as the optimal condition for nanoparticle preparation. Nanoparticle formation was confirmed using UV–Vis spectroscopy, showing a strong absorption band at 325 nm, indicative of oxide-based copper nanostructures and/or surface oxidation during green synthesis. XRD patterns revealed Cu2O as the dominant crystalline phase, characterized by reflections at 2θ ≈ 29.6°, 36.4°, 42.3°, 61.3°, 73.5°, and 77.3°, with a possible minor contribution from metallic Cu due to peak overlap. FTIR spectra confirmed the presence of biomolecules (O–H and C–H bands, along with carbonyl/COO−-related bands) involved in nanoparticle stabilization, as well as Cu–O vibrations around 600–620 cm−1 consistent with Cu2O. PSA showed a dominant hydrodynamic size in the 60–70 nm range (average 65 nm), whereas SEM indicated aggregation into micrometer-scale clusters upon drying. In vitro α-amylase inhibition assays demonstrated concentration-dependent inhibition, with CuNPs (IC50 6.18 μg/mL) and the extract + CuNPs mixture (IC50 6.83 μg/mL) approaching that of acarbose (IC50 5.04 μg/mL) and exhibiting stronger activity than the extract alone (IC50 8.89 μg/mL). The key contribution of this work is the development of a simple, aqueous, environmentally friendly route that leverages local biological resources while producing Cu2O-rich nanoparticles with α-amylase inhibitory activity approaching that of acarbose. These findings highlight the promise of a low-cost antidiabetic candidate for postprandial glucose control and provide a basis for further investigations into nanoformulation and preclinical evaluation.
Investigasi DFT terhadap Stabilitas dan Perilaku Ionisasi Senyawa Kompleks [Ag(NH3)n] (n = 1–4): DFT Investigation of the Stability and Ionization Properties of Ag(NH3)n Complexes (n = 1–4) Bonaventura, Ridho; Maarebia, Rosalinda Z.; Wijaya, Dwi Putra; Munandar, Nurharis; Hutagalung, Fajar Y. S. T.
CHEMISTRY PROGRESS Vol. 19 No. 1 (2026)
Publisher : Sam Ratulangi University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35799/cp.19.1.2026.68092

Abstract

ABSTRAK Pemahaman mengenai hubungan antara kestabilan dan proses ionisasi pada senyawa kompleks logam penting dalam pengembangan material fungsional dan sistem berbasis logam transisi. Penelitian ini bertujuan mengkaji pengaruh jumlah ligan NH3 terhadap kestabilan, sifat elektronik, dan karakteristik ionisasi kompleks [Ag(NH3)n] (n = 1–4) menggunakan metode Density Functional Theory (DFT). Optimasi geometri dilakukan untuk memperoleh struktur paling stabil, sedangkan analisis kestabilan dilakukan melalui energi pembentukan, energi stabilisasi, dan celah energi HOMO–LUMO. Karakteristik ionisasi dievaluasi menggunakan pendekatan AIP dan VIP dari hasil perhitungan optimasi dan frekuensi. Penelitian ini dilakukan secara komputasi dan perhitungan dilakukan dengan menggunakan basis set 6-3111++ G (d,p) untuk senyawa NH3, dan LANL2DZ ECP – B3LYP untuk unsur Ag & ion Ag+, dan untuk senyawa kompleks [Ag(NH3)n]+ (n=1-4) pada proses optimasi geometri. Sedangkan pada perhitungan opt+freq (optimasi dan frekuensi) untuk senyawa-senyawa kompleks [Ag(NH3)n] (n=1-4) dan [Ag(NH3)n]+ (n=1-4) digunakan basis set yang berbeda, yaitu SDD-ECP dengan fitting set DEF2SV. Hasil penelitian menunjukkan bahwa penambahan ligan NH3 meningkatkan kestabilan termodinamika kompleks, dengan [Ag(NH3)4] sebagai spesies paling stabil. Analisis HOMO–LUMO menunjukkan bahwa [Ag(NH3)2] memiliki kestabilan kinetik tertinggi. Nilai AIP dan VIP menurun secara bertahap seiring bertambahnya jumlah ligan, yang mengindikasikan peningkatan densitas elektron pada pusat logam Ag dan kemudahan pelepasan elektron. Hasil ini juga memberikan pemahaman yang lebih komprehensif mengenai peran ligan dalam mengatur kestabilan dan sifat elektronik kompleks perak–amonia, serta menjadi landasan teoritis bagi pengembangan material berbasis perak yang lebih efektif. ABSTRACT Understanding the relationship between stability and ionization processes in metal complexes is important for the development of functional materials and transition metal–based systems. This study aimed to investigate the effect of the number of NH3 ligands on the stability, electronic properties, and ionization characteristics of [Ag(NH3)n] complexes (n = 1–4) using Density Functional Theory (DFT). Geometry optimization was performed to obtain the most stable structures, while stability was evaluated through formation energy, stabilization energy, and HOMO–LUMO energy gap analyses. Ionization characteristics were assessed using Adiabatic Ionization Potential (AIP) and Vertical Ionization Potential (VIP) calculations based on optimized geometries and frequency analyses. Computational calculations were carried out using the 6-311++G(d,p) basis set for NH3 and the LANL2DZ effective core potential (ECP) combined with the B3LYP functional for Ag and Ag+ species during geometry optimization of the [Ag(NH3)n]+ complexes (n = 1–4). For geometry optimization and frequency calculations of neutral and ionized complexes, the SDD-ECP basis set with the DEF2SV fitting set was employed. The results showed that increasing the number of NH₃ ligands enhanced the thermodynamic stability of the complexes, with [Ag(NH3)4] exhibiting the highest stability. HOMO–LUMO analysis indicated that [Ag(NH3)2] possessed the greatest kinetic stability. Both AIP and VIP values decreased progressively with increasing ligand coordination, indicating higher electron density around the Ag center and a greater tendency for electron removal. These findings provide deeper insight into the role of ligands in governing the stability and electronic properties of silver–ammonia complexes and offer a theoretical basis for the development of more effective silver-based materials.
Co-Authors Chairil Anwar Dwi Putra Wijaya Henry Fonda Aritonang Hutagalung, Fajar Hutagalung, Fajar Y. S. T. Maarebia, Rosalinda Z. Munandar, Nurharis