Surface treatment study of hematite photoanode with atomic layer deposited zirconium(IV) oxide ultrathin film for water splitting applications

• Main Author: Low, Shu Han
• Other Authors: Alfred Tok Iing Yoong
• Format: Final Year Project
• Language: English
• Published: 2018
• Subjects: DRNTU::Engineering
• Online Access: http://hdl.handle.net/10356/74344
• Institution: Nanyang Technological University

This project sought to study the effect of enhancing photoelectrochemical cell (PEC) performance for water splitting applications through atomic layer deposition (ALD) surface treatment of ZrO2 on hematite photoanode. An introduction which includes the background information, objective and scope of this project would first be given. Next, a comprehensive and cogent review of previous works would be written, providing the reader with more information pertaining to the working principles of a PEC, strategies to enhance the overall PEC performance and the capabilities of the ALD method. Subsequently, this report will cover the experimental methodology which includes materials characterization, materials and methods used. Following the experimental methodology is the results section, whereby it showed that ALD ZrO2 coated hematite has demonstrated an overall positive impact on the PEC performance. The number of ALD deposition cycles can be fine-tuned to yield greater photocurrent density, thereby enhancing the PEC performance. The results showed that the photocurrent increases with increasing number of ALD deposition cycles. At 0.6 V vs. Ag/AgCl, the photocurrent density increases from 0.09 mAcm-2 at 0 ALD deposition cycle, to 0.13 mAcm-2 at 30 ALD deposition cycles, to 0.16 mAcm-2 at 60 ALD deposition cycles, and to 0.22 mAcm-2 at 90 ALD deposition cycles. PEC performance is best enhanced at 90 ALD deposition cycles, which yielded the highest photocurrent density of 0.22 mAcm-2. The improvement of PEC performance is mainly attributed to the improved charge transfer on hematite surface through the increased surface states. Lastly, a conclusion is made with further recommendations to improve on the current study for the benefit of ensuing research work in this field.