Article Per Year (5 Year)
p-Index From 2021 - 2026
0.444
P-Index
This Author published in this journals
All Journal Molluca Journal of Chemistry Education (MJoCE) International Journal of Renewable Energy Development
Semuel Unwakoly
Chemistry Education Study Program, Universitas Pattimura, Ambon
Chemistry Control & Systems Engineering Earth & Planetary Sciences Education Electrical & Electronics Engineering Energy Engineering

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

Found 2 Documents
Search

 1 
PROFILING CHEMISTRY STUDENTS’ SYSTEMS THINKING SKILLS IN RESPONDING TO 21ST-CENTURY CHALLENGES Nadia Amida; Semuel Unwakoly
Molluca Journal of Chemistry Education (MJoCE) Vol 15 No 2 (2025): MJoCE
Publisher : Program Studi Pendidikan Kimia, FKIP, Universitas Pattimura (Chemistry Education Study Program, Faculty of Teacher Training and Educational Sciences, Pattimura University)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30598/MJoCEvol15iss2pp68-73

Abstract

This study analyzes the profile of chemistry students’ systems thinking skills as a key competency for addressing the complex challenges of the 21st century. Systems thinking is essential for understanding the dynamic interrelationships among components within a system in an integrated and holistic manner. A descriptive quantitative approach was employed involving 108 chemistry education students from seven universities across Indonesia, consisting of 58 from rural areas and 50 from urban areas. Data were collected using the Dorani Systems Thinking Skills Test (D-STST), which was adapted to the higher education chemistry context. The results showed that students from urban areas achieved a higher mean score (M = 38.5) than those from rural areas (M = 34.91), indicating differences in systems thinking proficiency based on students’ residential backgrounds. These disparities are likely influenced by learning environments, access to educational resources, and academic experiences. The findings underscore the importance of implementing contextual, inquiry-based, and student-centered learning strategies to strengthen systems thinking skills and better prepare students for the demands of 21st-century education and global challenges.
Effect of solution pH and concentration of Dewandaru fruit extract as a natural dye on optical characteristics and performance of dye-sensitized solar cells Dadi Rusdiana; Eka Cahya Prima; Muhammad Nurul Ikhsan; Andhy Setiawan; Endi Suhendi; Arip Nurahman; Semuel Unwakoly; Arramel Arramel
International Journal of Renewable Energy Development Vol 15, No 5 (2026): September 2026
Publisher : Center of Biomass & Renewable Energy (CBIORE)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.61435/ijred.2026.61666

Abstract

Given growing global energy demand and the need for sustainable solutions, solar energy is a promising alternative. Dye-sensitized solar cells (DSSC) are a cost-effective photovoltaic technology, and natural dyes as sensitizers have significant potential to improve their efficiency. This study explores the use of a natural dye from the Dewandaru fruit (Eugenia uniflora) in DSSCs by varying pH and concentration. Natural dyes offer an environmentally friendly, sustainable alternative to synthetic dyes, which are often expensive and less eco-friendly. In this research, Dewandaru fruit extract was used to sensitize TiO2 photoanodes, and the effects of varying pH (1.00, 1.66, 2.27, and 3.00) and dye concentrations (2.5, 5.0, 7.5, and 10%) on optical properties and performance were analyzed. UV-Vis spectroscopy, FTIR, cyclic voltammetry, and J-V measurements were used to assess absorbance, energy levels, and efficiency. Optical characterization results showed that changes in pH and concentration can affect the dye’s absorbance and energy band gap. The dye achieved optimal DSSC performance at pH 3.00, yielding a Voc of 0.425 V, Jsc of 0.053 mA/cm², a fill factor of 68.7%, and an efficiency of 0.01548%. The best dye concentration was 10%, achieving a Voc of 0.45 V, a Jsc of 0.105 mA/cm², a fill factor of 69.0%, and an efficiency of 0.0322%. The statistical analysis indicates that pH has a substantial positive effect on DSSC efficiency and band gap energy. Moreover, dye concentration significantly affects DSSC efficiency, light-harvesting efficiency, Jsc, and fill factor, with the most substantial effects on efficiency and Jsc. However, concentration appears to have a smaller effect on dye absorbance, band gap energy, and HOMO/LUMO values. The study indicates that Dewandaru fruit extract has potential as a natural dye for DSSCs, with performance varying with pH and concentration. 
Co-Authors Andhy Setiawan Arip Nurahman Arramel Arramel Dadi Rusdiana Eka Cahya Prima Endi Suhendi Muhammad Nurul Ikhsan Nadia Amida