Dec 4, 2024
8:15am - 8:30am
Hynes, Level 3, Room 300
Young Sun Park1,Hyungsoo Lee1,Juwon Yun1,Gyumin Jang1,Chang-seop Jeong1,Jooho Moon1
Yonsei University1
The unassisted solar fuel photosynthesis using photoelectrochemical (PEC) configuration composed of photocathode and photoanode has emerged as a promising technology to solve both of energy crisis and environmental contamination. However, the lack of competitive photoanodes, which is ascribed to inferior light harvesting and suboptimal charge separation/injection characteristics of photoabsorbers constituting photoanodes, has been paramount barrier for efficient unbiased solar fuel production system. The one-dimensional (1D) nanostructured photoabsorber can be rational methodology to improve light absorption
via complex morphological property that allow light scattering as well as superior electron-hole separation ability by employing the favorable crystallographic direction. Along with these beneficial optoelectronic capabilities, the mesoporous 1D nanostructure promotes charge carrier injection to electrolyte
via large surface area, and the passivation strategy that alleviate surface trap states further elevates the extraction of photo-induced holes from photoelectrode to electrolyte by repressing charge carrier recombination.
Herein, we demonstrate solution-processed 1D Sb
2S
3 nanorod arrays deposited on substrate modified by Au seed layer. This Au seed layer modulate the interaction between molecules in precursor solution and substrate, resulting in self-orientated crystalline structure. Moreover, the (NH
4)
2WS
4 treatment was performed on the surface of Sb
2S
3 nanorod-based absorber, resulting in formation of WS
x layer which passivates surface states distributed on surface of photoabsorber. The resulting photoanode (denoted as WS-1D Sb
2S
3) was used to enable an iodide oxidation reaction (IOR), a prominent alternative to sluggish oxygen evolution reaction, revealing a photocurrent density of nearly 10 mA cm
–2 at 0.6 V versus the reversible hydrogen electrode. Afterwards, by coupling WS-1D Sb
2S
3 photoanode with perovskite-based photocathode in a parallel illumination configuration, the unbiased solar-to-hydrogen conversion device was afforded, exhibiting a solar to hydrogen conversion efficiency of 2.95% without external bias along with the stability of 2 h. Our study demonstrates the feasibility of unbiased solar fuel generation device using IOR on Sb
2S
3-based photoanode with facile morphology control and a surface passivation process.