High-performance Sb₂S₃ photoanode enabling iodide oxidation reaction for unbiased photoelectrochemical solar fuel production

Abstract

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...

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

“…The photocurrent density of our device maintained 92% of its initial value after 2 h, which was superior to our previous work. [ 13 ] The XRD and Raman measurements confirm that the Sb 2 S 3 phase of WS‐Sb 2 S 3 photoanode was unchanged after chronoamperometric test (Figure S19, Supporting Information). Moreover, the average FE of hydrogen generated by the cathodic electrode under mode P dual illumination of 1 sun was calculated as ≈96% based on a gas chromatography analysis (Figure S20, Supporting Information).…”

“…The iodide oxidation reaction (IOR) has been regarded as a promising anodic reaction due to its fast reaction kinetics (associated with the facile two‐electron‐transfer step) and the simultaneous formation of valuable by‐products (i.e., iodine) in the hygiene industry. [ 13 ] In addition, the IOR can be actively driven in acidic electrolytes, where the photocathode optimally operates the hydrogen evolution reaction (HER). In contrast, the photocathode generally sacrifices HER efficiency in neutral and/or alkaline electrolytes.…”

“…Moreover, Sb 2 S 3 n ‐type semiconductors possess a suitable bandgap of 1.6–1.8 eV for light harvesting in the entire visible wavelength, a superior light absorption coefficient (>10 5 cm −1 ), and a long carrier diffusion length of ≈900 nm. [ 13,16 ] In addition, it has recently been reported that solution‐processable Sb 2 S 3 polycrystalline‐based thin films are readily achievable without forming any secondary/impurity phase. [ 13 ] The resulting Sb 2 S 3 absorber was passivated by RuO 2 nanosheets, demonstrating high iodide oxidation capability as well as the feasibility of creating an efficient bias‐free hydrogen production device (i.e., with an operating current density of 4 mA cm −2 ) when OER was replaced by IOR.…”

“…[ 13,16 ] In addition, it has recently been reported that solution‐processable Sb 2 S 3 polycrystalline‐based thin films are readily achievable without forming any secondary/impurity phase. [ 13 ] The resulting Sb 2 S 3 absorber was passivated by RuO 2 nanosheets, demonstrating high iodide oxidation capability as well as the feasibility of creating an efficient bias‐free hydrogen production device (i.e., with an operating current density of 4 mA cm −2 ) when OER was replaced by IOR. However, considering their inferior optoelectrical factors and limited surface area (caused by the planar thin film of a polycrystalline with various facets), the IOR activity of Sb 2 S 3 ‐based photoanodes could be further improved if the absorber nanorods were vertically oriented.…”

Atomically isolated and unsaturated Sb sites created on Sb2S3for highly selective NO electroreduction to NH3

“…The EXAFS fitting data (Fig. 1g and Table S1 †) reveal the average coordination number (CN) of Sb 2 S 3 to be 4.2, much smaller than the crystallographic value of Sb 2 S 3 (CN = 5), 45 corroborating the existence of plentiful unsaturated Sb sites in Sb 2 S 3 . These XAS results reveal that the prepared Sb 2 S 3 naturally contains abundant atomically isolated and unsaturated Sb (Sb AIU ) sites, which are considered to be catalytically active towards NORR.…”