Rike Yudianti
Pusat Penelitian Fisika – LIPI

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THE EFFECT OF Pt LOADING ON ELECTROCHEMICAL PERFORMANCE OF CNT-BASED ELECTROCATALYST Yudianti, Rike; Onggo, Holia
Teknologi Indonesia Vol 37, No 3 (2014)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (16.051 KB) | DOI: 10.14203/jti.v37i3.230

Abstract

Pt loading on CNT surface as electrocatalyst support affects electrochemical performance of electrocatalyst and proton exchange membrane fuel cell stability. In some recent study, Pt-loaded electrocatalyst was a synthesis using poliol method, undergone by controling weight ratio of Pt percursor and CNT in order to find out the importance of appropriate Pt loading and configuration on electrochemical performance. According to the analysis, Pt-loaded electrocatalyst 23.4 and 36.3% show good material properties and electrochemical performance. Electrocatalyst 23.4% Pt loading was selected for preparing low Pt-loaded electrocatalyst layer by screen printing techniques. Nafion ionomer on electrocatalytic film plays an important role to determine the morphological electrocatalyst surface and performance in changing hydrophobicity and electrochemical properties. Nafion ionomer consequently causes reduction on electrochemical properties from 338.6 to 31.6 m2/g whereas the highest electrochemical surface area (ECSA) is achieved by Pt loading 23.4% in average particle size 3.7 nm, corresponding to Pt activity on hydrogen desorption.
PENGARUH PENAMBAHAN POLY(TETRAFLUOROETHYLENE) PADA KARAKTERISTIK KOMPOSIT BACTERIAL CELLULOSE/ MULTI-WALLED CARBON NANOTUBES Onggo, Holia; Yudianti, Rike
Teknologi Indonesia Vol 35, No 1 (2012)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (16.051 KB) | DOI: 10.14203/jti.v35i1.173

Abstract

In order to obtain new materials as alternative carbon paper, the bacterial cellulose/multi-walled carbon nanotube (BC/MWCNT) composites were made with and without PTFE by helping agarose, via heating process. The effect of PTFE addition on characteristic BC/MWCNT composite have been studied using thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and impedance bridge. The electrically conductivity of BC / MWCNT/ AG composite (without PTFE addition) is 15.1 x 10-2 S/cm (in-plane) and 0.3 x 10-2 S/cm (through plane). Above 150oC, the composite tends to be destroyed leading to electrical conductivity measurements cannot be performed. In the BC/MWCNT/AG/PTFE composite, heating from 150 to 330oC increased electrically conductivityfrom 4.5 to 24.5 x 10-2 S/cm (in-plane) while through-plane electrically conductivity tend to be stable (0.020.03x10-2 S/cm). After heating at 400oC, the composite was seen better thermal stability but the electrically conductivity was decrease because of carbon particles from AG and BC were decomposed and coating of MWCNT. The PTFE addition was not only for increasing the thermal stability but also as coating material of BC/MWCNT composites.
Optimization of Cu2O Thickness to Enhance Photocatalytic Properties of Electrodeposited Cu2O/FTO Photoanode Khasanah, Riza Ariyani Nur; Chien, Forest Shih-Sen; Prasetyowati, Rita; Yudianti, Rike
Bulletin of Chemical Reaction Engineering & Catalysis 2024: BCREC Volume 19 Issue 1 Year 2024 (April 2024)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.20081

Abstract

Currently, n-type cuprous oxide (Cu2O) is a promising material as photocatalyst because of its energy gap of 2 eV that absorbs visible light up to a wavelength of 600 nm. As a photoelectrode, the thickness of Cu2O is crucial, where the improper thickness may worsen the photocatalytic properties. This work aimed to enhance the photocatalytic properties of Cu2O electrodeposited on fluorine-doped tin oxide (FTO), called Cu2O/FTO, by optimizing the Cu2O thickness. The thickness of Cu2O was controlled by adjusting the deposition time in the electrochemical deposition of Cu2O/FTO. By changing the deposition time from 5 to 45 min, the morphology of Cu2O changed from a leaf-like shape to an irregular facet shape with highly dense coverage, and the average thickness increased from 370 to 1100 nm. The increasing Cu2O thickness resulted in the increasing light absorption. The Cu2O/FTO demonstrated anodic photocurrent, which increased with the Cu2O thickness up to a threshold value of 1000 nm (35 min deposition time). At a thickness of 1000 nm, Cu2O/FTO achieved the highest photocurrent (150 and 58 µA under irradiation of 365 and 470 nm, respectively) due to the highly dense morphology and high absorption. In addition, with a thickness of 1000 nm, the charge diffusion was still good. Further, the increase of Cu2O film thickness higher than 1000 nm caused low photocatalytic properties even though the morphology was highly dense, and the absorption was the highest. This condition could be due to the relatively too-high resistance of Cu2O that caused poor charge diffusion. Copyright © 2024 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).