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Synthesis of TiO2-Activated Carbon from Coffee Dregs by Hydrothermal Method for Photodegradation of Diazinon Haryati, Tanti; Zakaria, Helmy Ahmad; Sutisna, Sutisna; Suwardiyanto, Suwardiyanto; Sulistiyo, Yudi Aris; Andarini, Novita
Molekul Vol 20 No 1 (2025)
Publisher : Universitas Jenderal Soedirman

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20884/1.jm.2025.20.1.13714

Abstract

ABSTRACT. The photocatalytic activity of TiO₂ can be enhanced by binding it to materials with high adsorption capacity. The synthesis began with the mixture of 5 mL TTIP, 30 mL ethanol, and H₂O 30 mL stirred for 1 hour. Activated carbon made from coffee grounds in varying amounts (5 g, 10 g, and 15 g) was then added to the TTIP solution, and the mixture was stirred for 2 hours. The mixture was then placed in an autoclave, heated at 180°C for 12 hours, dried, and then calcined at 500°C for 3 hours. SEM morphological analysis showed that TiO₂ particles were attached to the surface of the activated carbon, which was further confirmed by EDX data showing the presence of Ti and O elements in the synthesized material. Furthermore, crystallinity and gap analyses demonstrated that the material was exclusively in the anatase phase. The largest surface area, 286.10 m²/g, was observed on titanium dioxide-activated carbon/10 (TiO₂-AC/10), exhibiting a mesoporous structure and microporous features. Photocatalytic tests for diazinon degradation demonstrated that TiO₂-AC/10 exhibited the most significant photocatalytic activity of 65.18%. The composite material's degradation capability diminished by 9-13% from the initial to the third cycle. The residual titanium elements within the composite material maintained stability, suggesting the integrity and durability of TiO₂ particles affixed to the surface of activated carbon. Keywords: TiO2-AC, Coffee Dregs, Diazinon, Photocatalysis, Reusability
One-Step Hydrothermal Synthesis of TiO2 Nanotubes and Photodegradation Activity towards Diazinon Haryati, Tanti; Diana, Alvina Nur; Sofiyah, Ovy; Nelumbium, Tusiana Putri; Andarini, Novita; Sulistiyo, Yudi Aris; Suwardiyanto, Suwardiyanto
Bulletin of Chemical Reaction Engineering & Catalysis 2023: BCREC Volume 18 Issue 4 Year 2023 (December 2023)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.20056

Abstract

The study aimed to analyze how variations in TiO2/NaOH mole ratio, stirring time, and washing pH affect the formation process of TiO2 nanotubes (TNT) through one-stage hydrothermal. TiO2 micro powder was mixed with 10M NaOH with the variation of TiO2/NaOH mole ratio (0.005:1, 0.015:1, and 0.025:1). The hydrothermal process was then conducted at 130 ℃ in an autoclave for 24 h with stirring time intervals of 10, 15, and 20 minutes/h. The samples underwent 1 M HCl washing to produce diverse pH variations (pH = 2, pH = 3, and pH = 4). Characterization of the synthesized TNT was conducted using SEM, TEM, XRD, SAA, and UV-Vis DRS. After analysis of the micrographs revealed the fiber shape of the particles, it was noted that TNT particle size increased due to smaller mole ratio variation, longer stirring, and lower pH. The synthesized TNT featured a tubular morphology with an inner diameter of 3.30 nm, an outer diameter of 6.15 nm, and a wall thickness of 1.64 nm. The increase in sodium titanate content of the sample results in an increase in surface area. Additionally, small pore size contributes towards an increase in both surface area and total pore size. The best result of the TNT photocatalytic test against diazinon can be observed in the fifth sample with a mole ratio of 0.025:1, stirring time of 20 minutes/h, and washing pH of 3. With an irradiation time of 210 min, diazinon degradation reached 90%. Copyright © 2023 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 
Response of mineral formulation towards different growth phases of arabica coffee in lowland Wulanjari, Distiana; Wijaya, Ketut Anom; Rosyady, Muhammad Ghufron; Suwardiyanto, Suwardiyanto; Meliala, Susan Barbara Patricia Sembiring; Setiyono, Setiyono; Farisi, Oria Alit
Jurnal Ilmu Pertanian Vol 9, No 1 (2024): April
Publisher : Faculty of Agriculture, Universitas Gadjah Mada jointly with PISPI

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ipas.76043

Abstract

Arabica coffee cultivation is limited by altitude, which affects its production. Some farmers in Jember Regency are innovating to grow arabica coffee in the lowland, but the potential for leaf rust disease is quite high. Plant natural resistance can be enhanced by adding minerals formulation (containing silica, iodine, and calcium). This research aimed to determine which phase is more effective for applying mineral formulation that induces plant resistance. The formulation was tested on arabica coffee plants grown at the lowland (460 masl) in Jember Regency on 12 years old (y.o) mature and 1 y.o immature plants. One formulation was dissolved in 14 L of water and applied by foliar feeding. The effect was analyzed using two-way T-test of two samples assuming unequal variances at 95% confidence level to determine the differences. The analysis showed that the plants supplemented with the formulation could increase the variables that supported the natural resistance of plants (both mechanically and through the production of chemical compounds), such as polyphenol content, flavonoids, antioxidant activity, total dissolved protein, vitamin C, reducing sugar, lignin, cellulose, hemicellulose, and iodine content in the plant. The response of the formulation application showed that the most resistance variables was better in 1 y.o immature plants than in 12 y.o mature plants. The application of mineral formulation in immature phase will have a better impact on increasing natural resistance, and it has the potential to be used as a supplement for arabica coffee plants cultivated in the lowland.