Modification of Ti‐doped Hematite Photoanode with Quasi‐molecular Cocatalyst: A Comparison of Improvement Mechanism Between Non‐noble and Noble Metals

Abstract

Loading of molecular catalyst on the surface of semiconductors is an attractive way to boost the water oxidation activity. As active sites, molecular water oxidation cocatalysts show increasing attraction and application possibility. In order to compare the advantages between molecular catalysts with non-noble and noble metals, the loading of the Fe(salen) and Ru(salen) as cocatalyst precursors on the surface of TiÀ Fe 2 O 3 was investigated Quasi-Fe(salen) and Ru(salen) improved the photocurrent density by 1.5 and 1.7 times compared to that of the original TiÀ Fe 2 O 3 photoanode, respectively. The quasi-Fe(salen) could improve the conductivity and reaction kinetics on the photoanode surface. By contrast, the notable advancements could be attributed to more reaction sites for quasi-Ru(salen) as cocatalysts. Thus, non-noble quasi-Fe(salen) is a promising cocatalyst to replace the noble metal salen, and further optimization can be expected with regard to the precise control of reaction sites.

Semiconductor‐based Photoanodes Modified with Metal‐Organic Frameworks and Molecular Catalysts as Cocatalysts for Enhanced Photoelectrochemical Water Oxidation Reaction

“…The Co−C−N ligands with porous structure is beneficial for exposing the metal sites as reaction sites thus improving the photo‐induced charge transfer and surface kinetics. We also compared the PEC performance of Ti‐Fe 2 O 3 with the modification of noble and unnoble metal‐based molecular catalysts [109] . The Fe(salen) and Ru(salen) were dropped on the surface of Ti‐Fe 2 O 3 followed by heat‐treatment at 200 °C in air.…”

How titanium and iron are integrated into hematite to enhance the photoelectrochemical water oxidation: a review

“…On the other hand, as a result of productive beneficial effects, Ti-modified hematite photoanodes have been extensively utilized as the starting material for post-treatment to obtain a higher PEC performance. 19–25 These increasing interests also stimulate an outline of recent advancements of Ti-based modifications to contribute to the further development of hematite-based PEC water splitting systems. Practically, the overview of Ti-modified hematite photoanodes has been involved in recent literature reports, 26–28 but there is a rare study to summarize the multiple beneficial effects of Ti-based modifications elaborately and comprehensively.…”

Robust Carbon Nitride Homojunction Photoelectrode for Solar-Driven Water Splitting

“…Photoelectrochemical (PEC) cells can convert solar light into clean chemical fuels, such as hydrogen, through redox chemical processes driven by photogenerated electrons and holes at the surfaces of photoelectrodes. − It is one of the most feasible solutions to solve the crises of energy shortage and environmental pollution. − In PEC water splitting systems, the structure and chemical properties of photoelectrode materials determine the water splitting pathway and energy conversion efficiency. Therefore, the construction of an eco-friendly, stable, and efficient photoelectrode has been a prerequisite and hotspot in PEC water splitting.…”