Surface‐Passivated Vertically Oriented Sb2S3 Nanorods Photoanode Enabling Efficient Unbiased Solar Fuel Production

• Published in: Advanced energy materials 2023-08, Vol.13 (29), p.n/a
• Main Authors: Park, Young Sun, Lee, Juwon, Lee, Hyungsoo, Yun, Juwon, Jang, Gyumin, Lee, Jeongyoub, Son, Sanguk, Lee, Chan Uk, Jeong, Chang‐Seop, Moon, Subin, Lee, Soobin, Kim, Hyoung‐il, Moon, Jooho
• Format: Article
• Language: English
• Subjects: antimony trisulfide; Arrays; Crystallography; Fuel production; Fuels; Hydrogen; Hydrogen evolution reactions; Hydrogen production; iodide oxidation reaction; Nanorods; nanorod‐based photoanodes; Optoelectronics; Orientation effects; Oxidation; Perovskites; Photoanodes; Photocathodes; Photoelectric effect; photoelectrochemical hydrogen production; Substrates; unbiased solar to hydrogen conversion
• ISSN: 1614-6832; 1614-6840
• DOI: 10.1002/aenm.202301166

The lack of highly efficient photoanodes presents a significant challenge to implementing the promising strategy of unbiased solar‐to‐fuel conversion. To achieve high‐performance photoanodes, improving their light harvesting and charge separation/injection capabilities is indispensable. Herein, solution‐processed vertically oriented Sb2S3 nanorod arrays on substrate are obtained via a Au seed layer, resulting in improved optoelectronic properties (due to the light scattering effect) and favorable crystallographic orientation of the 1D nanostructure. Moreover, the (NH4)2WS4 treatment caps the surface of the nanorods with an amorphous WSx layer and passivates the sulfur vacancy of Sb2S3, resulting in boosted charge extraction to the reactants. The resulting photoanode is employed to drive an iodide oxidation reaction (IOR), which is a prominent alternative to sluggish water oxidation reactions, exhibiting a high photocurrent density of 13 mA cm−2 at 0.6 V versus the reversible hydrogen electrode. Subsequently, an unassisted hydrogen generation device is demonstrated by combining an Sb2S3 nanorod array‐based photoanode for IOR and a perovskite‐based photocathode for the hydrogen evolution reaction, achieving an efficient hydrogen production current density of 5.7 mA cm−2 without any external bias. A vertically oriented Sb2S3 nanorod is developed by modulating the interaction of precursor ink with an Au‐seeded substrate. The vertically oriented Sb2S3 nanorods are treated with (NH4)2WS4 to alleviate recombination centers. The resulting WSx‐capped Sb2S3 photoanode x is connected with a perovskite‐based photocathode to implement unassisted hydrogen production, achieving a photocurrent density of 5.7 mA cm−2 without any external bias.