Chemistry and Materials

Decorating Cu2O with Copper Metal (Cu) through Facile Electrochemical Deposition for Methylene Blue Degradation

Shyla Noureen Zahra — 2024-10-31

A cuprous oxide (Cu₂O) thin film was decorated with copper metal (Cu) using a simple electrochemical deposition method on a substrate of indium tin oxide at a potential of -0.3 V vs. Ag/AgCl and a temperature of 60 °C. This study aimed to investigate the role of Cu as a co-catalyst. The structure, phase, and morphology of Cu₂O/Cu were characterized by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy, respectively. The electrocatalytic performance of Cu₂O/Cu was recorded using linear sweep voltammetry and electrochemical impedance spectroscopy techniques. The X-ray diffraction and scanning electron micrograph show that Cu was successfully deposited covering Cu₂O. The current density of Cu₂O/Cu increased by 2.70 mA/cm²confirming the lower charge current resistance of 2.48 kΩ. The Cu-decorated Cu₂O demonstrated an improved photocatalytic activity, as shown by increased MB degradation from 46.33% to 50.87%. It was believed from characterizations that Cu deposition leads to more dense carriers and charge transfer, hence higher photocatalytic activity towards MB degradation than bare Cu₂O thin film.

Electrodeposition of Thin Film Cu-Zn-Sn Alloy for Water Splitting Application

Reinardo Ramawijaya Widakusuma — 2024-10-31

An energy transition to renewable energy sources is necessary due to the scarcity of fossil fuels and their detrimental effects on the environment. Water splitting process is one of the practical and effective way that does not occur spontaneously. This study investigates catalytic activity of Cu-Zn-Sn (CZT) photocatalyst in hydrogen evolution and oxygen evolution reaction. The CZT deposited with varied electrolyte’s pH of 6 and 9 on indium tin oxide substrate at the room temperature for 600 seconds. According to the X-ray diffraction patterns, there were Cu₆Sn₅, Cu₅Zn₈, and Sn metal phases with monoclinic, cubic, and cubic crystal systems. The scanning electron microscopy technique results of all CZT alloy sample showed a dense, non-uniform, and polycrystalline surface structure. The CZT alloys were found to have an average particle size of 0.35 μm. CZT alloys can produce a photocurrent density of 0.19 mA/cm² at a potential of 1.29 V vs RHE. the charge transfer resistance of CZT synthesized at pH 6 is lower (21.48 Ω) compared to pH 9 (28.36 Ω). The Tafel slope of HER for pH 9 CZT was -133 mV/dec, which was lower than that of pH 6 CZT (-88 mV/dec), indicating faster H₂ production and corrosion resistance on pH 9 CZT.

Additive-free Electrodeposition of SnCoNi Trimetallic Catalysts for Ethanol Electrooxidation

Qori'atun Ni'mah Salsabila — 2024-10-31

SnCoNi catalysts were synthesized via electrodeposition, with and without citric acid, to assess their ethanol electrooxidation performance. The additive-free catalyst exhibited superior properties, including lower charge transfer resistance and a smaller Tafel slope compared to the citric acid-modified catalyst. Chronoamperometry testing further revealed better electrochemical stability for the additive-free catalyst, with less current loss over time. Cyclic voltammetry confirmed the enhanced ethanol oxidation activity with a relatively high current density. The improved performance is attributed to better mass transport, active site exposure, and the synergistic effects of Sn, Co, and Ni in the additive-free catalyst, making it more efficient for ethanol electrooxidation. These findings suggest that the additive-free catalyst exhibits more favorable properties for ethanol electrooxidation compared to its citric acid-modified counterpart.

Synthesis of Copper(I) Oxide Thin Film Through Potentiostatic Electrodeposition as an Antioxidant Film

Muhammad Adya Raihan — 2024-10-31

Research on metal-based nanoparticles, such as silver, gold, and copper(I) oxide (Cu₂O), has drawn considerable attention due to their potential applications in catalysis, antioxidants, antimicrobials, and anticancer fields. In this study, we successfully deposited Cu₂O antioxidant films on indium tin oxide substrates through potentiostatic electrodeposition. The X-ray diffraction characterization revealed distinct peaks at 2θ value of 36.32°, 42.21°, and 61.30°, indicating the crystal structure of Cu₂O thin film. The scanning electron microscopy image showed the three-sided pyramid morphology of Cu₂O particles with average size of 316.18 nm. The energy dispersive X-ray spectrum confirmed the purity of the thin film, which is composed only of Cu and O elements without any impurities. The photoelectrochemical showed that the deposited Cu₂O has a maximum photocurrent density of 8.37 mA/cm² under visible light irradiation and 1.40 mA/cm² without irradiation. In addition, this study also found that the highest inhibition values of DPPH (2,2-diphenyl-1-picrylhydrazyl) radicals were observed when ascorbic acid was added.

The Effect of Saccharin on SnNi Alloy: the Electrodeposition and its Electrocatalytic Activity in Ethanol Oxidation Reaction

Rinda Mulmeyda — 2024-10-31

The development of Direct Ethanol Fuel Cell (DEFC) has attracted much attention, as alternative energy sources due to its various advantages. However, among its various advantages, DEFC has several problems, such as the kinetics of the ethanol oxidation reaction. Transition metal-based catalysts such as nickel and tin are considered as potential catalysts for DEFC due to their oxophilic properties that can improve catalytic activity. In this study, the effect of saccharin on SnNi bimetallic alloy catalyst synthesized by electrodeposition method on copper wire substrate was investigated. SnNi samples were characterized by several techniques, including X-ray diffraction, Scanning electron microscopy, and energi dispersive X-ray spectrocopy. Saccharin addition had a significant effect on the morphology, crystallite size, and composition of the catalyst. The presence of saccharin causes the formation of more uniform particles and has a smaller size. The sample with the addition of saccharin had a smaller charge transfer resistance value 4.82 Ω, lower tafel slope by 115 mV/dec, and show higher j_f/j_b ratio by 0.55. Furthermore, as the current density decreases, the SnNi catalyst with saccharin has a slow decrease rate and higher stability than the SnNi catalyst without saccharin.