Prospects of electrochemically synthesized hematite photoanodes for photoelectrochemical water splitting: A review

• Published in: Journal of photochemistry and photobiology. C, Photochemistry reviews Vol. 33; pp. 54 - 82
• Main Authors: Phuan, Yi Wen, Ong, Wee-Jun, Chong, Meng Nan, Ocon, Joey D.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.12.2017; Elsevier Science Ltd
• Subjects: Annealing; Band gap; Design engineering; Electrodeposition; Electrodes; Energy gap; Hematite; Heterojunctions; Photoanodes; Photoelectrochemical; Reviews; Solar energy; Splitting; State-of-the-art reviews; Substrates; Surface treatment; Synthesis; Temperature; Water splitting; Hematite; Water splitting; Photoelectrochemical; Solar energy
• ISSN: 1389-5567; 1873-2739
• DOI: 10.1016/j.jphotochemrev.2017.10.001

[Display omitted] •Electrochemically synthesized hematite-based photoanodes are reviewed.•Principles and mechanisms of electrochemically synthesis of hematite are presented.•Important advancements on the modifications of hematite photoanodes are elucidated.•Future challenges and prospects for sustainable energy development are highlighted. Hematite (α-Fe2O3) is found to be one of the most promising photoanode materials used for the application in photoelectrochemical (PEC) water splitting due to its narrow band gap energy of 2.1eV, which is capable to harness approximately 40% of the incident solar light. This paper reviews the state-of-the-art progress of the electrochemically synthesized pristine hematite photoanodes for PEC water splitting. The fundamental principles and mechanisms of anodic electrodeposition, metal anodization, cathodic electrodeposition and potential cycling/pulsed electrodeposition are elucidated in detail. Besides, the influence of electrodeposition and annealing treatment conditions are systematically reviewed; for examples, electrolyte precursor composition, temperature and pH, electrode substrate, applied potential, deposition time as well as annealing temperature, duration and atmosphere. Furthermore, the surface and interfacial modifications of hematite-based nanostructured photoanodes, including elemental doping, surface treatment and heterojunctions are elaborated and appraised. This review paper is concluded with a summary and some future prospects on the challenges and research direction in this cutting-edge research hotspot. It is anticipated that the present review can act as a guiding blueprint and providing design principles to the scientists and engineers on the advancement of hematite photoanodes in PEC water splitting to resolve the current energy- and environmental-related concerns.