Atomic Layer Deposition of Platinum Catalysts on Nanowire Surfaces for Photoelectrochemical Water Reduction

• Published in: Journal of the American Chemical Society Vol. 135; no. 35; pp. 12932 - 12935
• Main Authors: Dasgupta, Neil P, Liu, Chong, Andrews, Sean, Prinz, Fritz B, Yang, Peidong
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 04.09.2013
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja405680p

The photocathodic hydrogen evolution reaction (HER) from p-type Si nanowire (NW) arrays was evaluated using platinum deposited by atomic layer deposition (ALD) as a HER cocatalyst. ALD of Pt on the NW surface led to a highly conformal coating of nanoparticles with sizes ranging from 0.5 to 3 nm, allowing for precise control of the Pt loading in deep submonolayer quantities. The catalytic performance was measured using as little as 1 cycle of Pt ALD, which corresponded to a surface mass loading of ∼10 ng/cm2. The quantitative exploration of the lower limits of Pt cocatalyst loading reported here, and its application to high-surface-area NW photoelectrodes, establish a general approach for minimizing the cost of precious-metal cocatalysts for efficient and affordable solar-to-fuel applications.