Dataset for Probing the structure of D2O ice layers on ALD-grown ZrO2, Al2O3 and TiO2 thin films by sum frequency generation (SFG) spectroscopy

This dataset contains relevant raw and processed data supporting the paper entitled:"Probing the structure of D2O ice layers on ALD-grown ZrO2, Al2O3 and TiO2 thin films by sum frequency generation (SFG) spectroscopy".Faraday Discussions, 2026, DOI: 10.1039/D5FD00152H

Abstract

Sum frequency generation (SFG) spectroscopy was applied to investigate D2O adsorption on atomic layer deposition (ALD)-grown Al2O3, ZrO2, and TiO2 films at 94 ± 1 K. Film composition and thickness were characterized by ellipsometry and X-ray photoelectron spectroscopy (XPS). Additional SFG measurements were conducted on the SiO2/Si wafer and on a CoO film prepared by oxidizing Co foil. At D2O exposure below 3000 L, the spectra were dominated by interfacial features originating from the ice–oxide interface. These spectra exhibited a weak, broad O–D stretching band (OD3) centered at 2650 cm−1, tentatively attributed to (dissociated) water molecules hydrogen-bonded to the oxide surface; this assignment was supported by the absence of the OD3 feature on the SiO2/Si substrate. A sharp peak at 2730 cm−1 was also observed and assigned to the “free” O–D stretch (non-hydrogen-bonded with any neighboring molecule) of surface D2O molecules pointing into the vapor phase. Upon increasing D2O exposure, both the OD3 and “free” OD bands decreased in intensity and were replaced by weakly hydrogen-bonded OD2 and strongly hydrogen-bonded OD1 modes associated with the ice–vapor interface. As the exposure increased further, the OD2 and OD1 bands shifted to lower wavenumbers (2310 to 2284 cm−1) and became stronger, with the OD1 mode exhibiting a larger red shift and more pronounced intensity enhancement. No significant differences in water structure were observed on the Al2O3, ZrO2, and CoO films at the ice–vapor interfaces, apart from an approximately fivefold reduction in intensity on CoO, which is attributed to signal scattering from the rough CoO film/Co foil surface. However, when D2O exposure reached ≥30000 L, the OD1 band on the TiO2 surfaces decreased substantially in intensity and shifted to much lower wavenumbers (2065 cm−1 at 30000 L; 2030 cm−1 at 102000 L) than on Al2O3 (2283 cm−1 at 90000 L), ZrO2 (2293 cm−1 at 30000 L), and CoO (2284 cm−1 at 900000 L), indicating specific hydrogen-bonding interactions on the TiO2 surface.

The dataset contains files, as described below:

Sum frequency generator spectroscopy data - contains results of SFG spectroscopic data acquired for ALD-grown ZrO2, Al2O3, TiO2 thin films, and SiO2 reference under various conditions: SFG intensity (a.u.) and wavenumber (cm-1). These raw results were used to generate Figures 2-10 and S3, and S9, as follows:

Figure 2_ppp-SFG spectra under UHV.txt

Figure 3_ppp-SFG spectra of oxide films at 100 K under UHV in the range of 3000–3800 cm-1.txt

Figure 4_ppp-SFG spectra of D2O adsorption.txt

Figure 5_ppp-SFG spectra of D2O adsorbed on a Si wafer with increasing D2O exposure at 93–95 K.txt

Figure 6_ppp-SFG spectra in the O–D stretching region of D2O adsorbed on an ALD-grown Al2O3 film on Si wafer with increasing D2O exposure at 93–95 K.txt

Figure 7_ssp-SFG spectra in the O–D stretching region of D2O adsorbed on an ALD-grown Al2O3 film on Si wafer with increasing D2O exposure at 93–95 K.txt

Figure 8_ppp-SFG spectra in the O–D stretching region of D2O adsorbed on an ALD-grown ZrO2 film on Si wafer with increasing D2O exposure at 93–95 K.txt

Figure 9_ppp-SFG spectra in the O–D stretching region of D2O adsorbed on an ALD-grown TiO2 film on Si wafer with increasing D2O exposure at 93–95 K.txt

Figure 10_ppp-SFG spectra in the O–D stretching region of D2O adsorbed on CoO film/unpolished Co foil with increasing D2O exposure at 93–95 K.txt

Figure S3_ppp-SFG spectra of blank Si at 100 and 295 K under UHV in the range of 3000-3800 cm-1.txt

Figure S9_ppp-SFG spectra of D2O adsorption on CoO/Co foil (unpolished) at 93-95 K in the range of 3000-3800 cm-1.txt