Plasmon-Enhanced Photoelectrochemical Water Splitting Using Au Nanoparticles Decorated on Hematite Nanoflake Arrays

• Published in: ChemSusChem Vol. 8; no. 4; pp. 618 - 622
• Main Authors: Wang, Lei, Zhou, Xuemei, Nguyen, Nhat Truong, Schmuki, Patrik
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01.02.2015; WILEY‐VCH Verlag; Wiley Subscription Services, Inc
• Subjects: Electrodes; Ferric Compounds - chemistry; Ferric Compounds - radiation effects; gold; Gold - chemistry; Gold - radiation effects; hematite; nanoflakes; Nanostructures - chemistry; Nanostructures - radiation effects; Oxidation; Oxidation-Reduction; Photochemical Processes; Photosensitizing Agents - chemistry; Photosensitizing Agents - radiation effects; plasmonic metal; Platinum - chemistry; Silver - chemistry; Sunlight; Water - chemistry; water splitting; gold; hematite; water splitting; nanoflakes; plasmonic metal
• ISSN: 1864-5631; 1864-564X
• DOI: 10.1002/cssc.201403013

Hematite nanoflake arrays were decorated with Au nanoparticles through a simple solution chemistry approach. We show that the photoactivity of Au‐decorated Fe2O3 electrodes for photoelectrochemical water oxidation can be effectively enhanced in the UV/Visible region compared with the bare Fe2O3. Au‐nanoparticle‐decorated Fe2O3 nanoflake electrodes exhibit a significant cathodic shift of the onset potential up to 0.6 V [vs. reversible hydrogen electrode (RHE)], and a two times increase in the water oxidation photocurrent is achieved at 1.23 VRHE. A maximum photocurrent of 2.0 mA cm−2 at 1.6 VRHE is obtained in 1 M KOH under AM 1.5 (100 mW cm−2) conditions. The enhancement in photocurrent can be attributed to the Au nanoparticles acting as plasmonic photosensitizers that increase the optical absorption. It′s not only gold that sparkles: We form 1D hematite nanoflake arrays that are decorated with plasmonic Au nanoparticles through a simple solution chemistry approach. We find a significant improvement of the solar water splitting performance due to increased light absorption. This can be attributed to the Au nanoparticles that act as plasmonic photosensitizers.