2025-03-24 ノースカロライナ州立大学（NC State）
＜関連情報＞
- https://news.ncsu.edu/2025/03/24/tincone-for-co2-tech/
- https://pubs.acs.org/doi/10.1021/acsaem.4c02997
Si光電面のための光電気化学的に安定で効率的な電子輸送層としてのマイルドアニール分子層蒸着（MLD）ティンコン薄膜 Mild-Annealed Molecular Layer Deposition (MLD) Tincone Thin Film as Photoelectrochemically Stable and Efficient Electron Transport Layer for Si Photocathodes
Hyuenwoo Yang,Christopher J. Oldham,Carrie L. Donley,Renato N. Sampaio,John C. Dickenson,Pierpaolo Vecchi,K. Arun Joshi Reddy,Paul A. Maggard,Gerald J. Meyer,and Gregory N. Parsons
ACS Applied Energy Materials Published: February 22, 2025
DOI:https://doi.org/10.1021/acsaem.4c02997
Abstract
Metalcone thin films, composed of inorganic–organic hybrids, are synthesized using molecular layer deposition (MLD) through reactions between organometallic precursors (e.g., Sn, Al, and Ti) and organic reactants (e.g., ethylene glycol and glycerol). Despite their unique properties, metalcones exhibit significant vulnerability to water due to their organic components, limiting their potential in electrochemical applications. This study focuses on enhancing the photoelectrochemical stability of tincone thin films in aqueous electrolyte while preserving their hybrid characteristics through mild annealing in air at 250 °C. As-deposited and vacuum-annealed tincone thin films exhibited significant degradation under these conditions, while high-temperature-annealed (500 °C) tincone thin films offered improved stability with a significant decline in charge transfer efficiency. In contrast, mild annealing in air maintained the C–O bond at half level and improved the stability and charge transport without compromising the unique characteristics of tincone. This was confirmed by ellipsometry, X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FTIR). Mild-annealed tincone deposited on a lightly doped p-type silicon (p-Si) photocathode produced a 20-fold increase in CO volume compared to high-temperature annealed tincone in a CO2-saturated potassium bicarbonate (KHCO3) electrolyte with dispersed graphene oxide–cobalt phthalocyanine (GO-CoPc) under 1 sun illumination at 0.9 V vs reversible hydrogen electrode (RHE), while maintaining the faradaic efficiency for CO and H2. These results suggest that mild-annealed tincone thin films hold significant potential as protective charge transport layers on silicon photocathodes for the aqueous CO2 reduction reaction (CO2RR).
