Article Per Year (5 Year)
p-Index From 2020 - 2025
0.408
P-Index
This Author published in this journals
All Journal JURNAL KIMIA SAINS DAN APLIKASI
Gunawan Gunawan
Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University, Jl. Prof. Soedarto, SH., Tembalang, Semarang 50271|Diponegoro University|Indonesia
Chemical Engineering, Chemistry & Bioengineering Chemistry Engineering

Published : 2 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 2 Documents
Search

 1 
Synthesis, Characterization of Ag2s from AgCl Waste of Argentometry Titration with Heating Temperature Variations and Its Application as a Temperature Sensor Based on Negative Temperature Coefficient (NTC) Gunawan Gunawan; Sarahtrinita Glikeria Like Megawati; Nor Basid Adiwibawa Prasetya; Roni Adi Wijaya
Jurnal Kimia Sains dan Aplikasi Vol 25, No 8 (2022): Volume 25 Issue 8 Year 2022
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jksa.25.8.292-299

Abstract

Synthesis of Ag2S from AgCl waste of argentometric titration with heating temperature variations as a temperature sensor has been done. This study aims to synthesize Ag2S and examine the effect of heating temperature on crystal quality and electrical characteristics as a temperature sensor based on the Negative Temperature Coefficient (NTC). Ag2S synthesis was carried out by precipitation in a water bath with various heating temperatures of 40°C, 60°C, and 80°C. The success of the synthesis was confirmed by X-Ray Diffraction (XRD) with a typical peak of 2θ from Ag2S standard at 29.07°, 31.60°, 36.97°, 37.81°, and the highest crystallinity was obtained at a heating temperature of 60°C. Meanwhile, UV-Vis Diffuse Reflectance Spectroscopy (DRS UV-Vis) showed a band gap corresponding to Ag2S (0.9-1.05 eV). Furthermore, the Ag2S powder was made into pellets and applied as a temperature sensor. Then the resistance value and the electrical characteristics of the resulting sensor were measured. The best resistance was obtained from Ag2S synthesized at a temperature of 60°C with constant (B) and sensitivity (α) values of 2974 K and −3.35%, respectively. This indicated that Ag2S had been successfully synthesized, and the best sensor quality was obtained from Ag2S heated at a temperature of 60°C.
Effect of Ascorbic Acid Concentration on Cu2O Production for Photoelectrochemical Water Splitting on Photocathode Thin Films Kharisma Luthfiaratri Rahayu; Abdul Haris; Gunawan Gunawan
Jurnal Kimia Sains dan Aplikasi Vol 25, No 12 (2022): Volume 25 Issue 12 Year 2022
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jksa.25.12.442-449

Abstract

Hydrogen energy has great potential as a renewable energy source. Electrochemical water-splitting can be employed to obtain hydrogen by converting solar energy into hydrogen. In this study, Cu2O thin film electrodes have been successfully synthesized using ascorbic acid using the spin coating method. This study aimed to determine the effect of ascorbic acid in manufacturing Cu2O semiconductors as photocathodes and their activity for electrochemical water-splitting. The results indicated that ascorbate affected the photon current and onset potential of the Cu2O semiconductor. The synthesis results found that Cu2O at C1 (lower concentration than Cu2+) yielded 95.69%, and the yield for Cu2O at C2 (concentration equal to Cu2+) was 96.2%. The yield for Cu2O at C3 (concentration greater than Cu2+) was 99.82%. The photon currents generated by adding 3%, 6%, and 9% ascorbate solution were 1.18, 1.69, and 1.78 mA/cm2, respectively, at 0.3 V vs. RHE (Reversible Hydrogen Electrode). X-ray diffraction analysis revealed that the sample consisted of Cu2O C3 with an average grain size of 17.55 nm. Meanwhile, Cu2O C1 and Cu2O C2 had average grain sizes of 38.99 nm and 36.42 nm, respectively. SEM analysis showed the presence of Cu2O with a cuboid and flower-like morphology. EDX analysis showed that the samples contained elements of Cu: O, 73.97%: 26.03%; 79.89%: 20.11% and 98.43%: 1.57% respectively.
Co-Authors Abdul Haris Kharisma Luthfiaratri Rahayu Nor Basid Adiwibawa Prasetya Roni Adi Wijaya Sarahtrinita Glikeria Like Megawati