High-performance SbS photoanode enabling iodide oxidation reaction for unbiased photoelectrochemical solar fuel production

• Published in: Energy & environmental science 2022-11, Vol.15 (11), p.4725-4737
• Main Authors: Park, Young Sun, Jin, Xiaoyan, Tan, Jeiwan, Lee, Hyungsoo, Yun, Juwon, Ma, Sunihl, Jang, Gyumin, Kim, Taehoon, Shim, Sang Gi, Kim, Kyungmin, Lee, Jeongyoub, Lee, Chan Uk, Hwang, Seong-Ju, Moon, Jooho
• Format: Article
• ISSN: 1754-5692; 1754-5706
• DOI: 10.1039/d1ee02940a

The traditional photoelectrochemical (PEC) tandem configuration of hydrogen evolution reaction and oxygen evolution reaction (OER) demands a considerable potential of 1.8 V due to theoretical water splitting potential as well as a large overpotential mainly derived by sluggish OER kinetics. The iodide oxidation reaction (IOR) is a promising alternative to OER due to its low thermodynamic energy and two-electron-involved fast reaction kinetics. Herein, we report a high-performance catalyst-modified Sb 2 S 3 photoanode to drive IOR. A compact thin-film-type Sb 2 S 3 absorber is fabricated via solution processing based on a thorough understanding of the molecular interaction in the precursor ink state. Moreover, the deposition of a multilayered catalyst RuO 2 nanosheet and polydiallyldimethylammonium chloride not only efficiently enhances the charge transfer kinetics but also passivates the surface defects of the Sb 2 S 3 absorber. The resulting photoanode exhibits an efficient photocurrent density of 10 mA cm −2 at 0.54 V compared to the normalized hydrogen electrode in hydroiodic acid. In conclusion, we demonstrate a bias-free PEC tandem device based on a RuO 2 -modified Sb 2 S 3 photoanode paired with a silicon photocathode, yielding an operation current density of 4 mA cm −2 . The Sb 2 S 3 -based photoanode is combined with a silicon photocathode for implementing a bias-free photoelectrochemical tandem device driving hydrogen evolution reaction coupled with IOR, affording operation current density of 4 mA cm −2 .