SYNTHESIS OF MILL-SCALE DERIVED ?-FE2O3 AS POTENTIAL PHOTOANODE FOR HYDROGEN PRODUCTION IN WATER SPLITTING PROCESS

• Main Author: Wisely, Nick
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/70303
• Institution: Institut Teknologi Bandung

Hydrogen is the most superior energy storage medium in terms of energy capacity and length of storage time compared to other energy storage media. The process of hydrogen production can be realized, one of which is by using the method of separating water through a photoelectrochemical process. In the photoelectrochemical process, the help of semiconductor materials is needed to carry out charge transfer so that the water splitting process occurs. One of the interesting semiconductors to study is hematite. In this research, the process of utilizing hematite as an effective photoanode for water separation process originating from mill-scale processing is waste made from iron-rich elements. In the process of processing mill-scale into hematite, two approaches are carried out, namely direct combustion, selective oxidation, and dissolution with oxalic acid, oxalate precipitation. The two hematites from each process were characterized through X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Emission Dispersive X-ray Spectroscopy (EDX) tests. Based on the results obtained, it was observed that both methods produced two hematite pods that differed in morphology, color and crystalline size. The morphology of the selective oxidation method produces hematite which is easily agglomerated and produces a larger crystalline size than hematite resulting from oxalate precipitation. As a photoanode, hematite was deposited by the electrophoretic deposition method, with a growth time of 1 minute and a voltage variation. The thickness of the hematite can be adjusted through the magnitude of the growth stress in the electrophoretic deposition (EPD) process. It was observed that the oxalate precipitation hematite results much better in forming a layer as a photoanode. To date, this research is the first to conduct a study on mill-scale processing of photoanodes in a photoelectrochemical process. In its use as a photoanode, hematite has an active response to light in the on/off cycle test. The results of the Linear Sweep Voltametry (LSV) test observed that hematite gave an increase in photocurrent density compared to FTO substrate alone. The highest efficiency is obtained when the growth potential is given at 10 V within 1 minute of growth.