## 2 Materials and Methods  
FS samples with a thickness of 1 mm were selected as glass substrates. Prior to mechanical tests, the glass substrates were ultrasonically cleaned sequentially in acetone and ethanol solutions for 5 min, and finally rinsed with deionized water before drying with nitrogen gas. To prepare various concentration of H2O2 solutions, the H2O2 solution of 30 wt% (purchased from Chengdu cologne chemicals Co., Ltd., Chengdu, China) was mixed with pure water, and the final concentrations of H2O2 solutions were set as 0 wt%, 5 wt%, 10 wt%, and 20 wt%, where the 0 wt% was prepared as the deionized water only for comparison. The glass samples were immersed in various solutions for 3 h, and then taken out and dried with nitrogen gas for the subsequent experiments. The chemical composition of treated glass samples was detected by Raman spectroscopy. Using a contact angle tester, the water contact angle of glass surfaces was detected in humid air (RH = 40%); all water contact angle tests were repeated independently at least five times to ensure the repeatability of the experiments. In order to compare the distribution of hydroxyl groups on various FS surfaces, vibrational sum frequency generation (SFG) spectroscopy was employed. The details of the experimental setup of the SFG spectrometer were described elsewhere [16]. Visible pulses (532 nm) and tunable IR pulses (2.5-10 um) generated with an EKSPLA laser system were spatially and temporally overlapped at the glass surface. The incident angles of visible and IR pulses were 60\({}^{\circ}\) and 56\({}^{\circ}\), respectively. The visible and IR pulse energies of the samples were 3 mJ and 1.5 mJ, respectively. The polarization combination for the spectra collected was \(s\) for SFG signal, \(s\) for visible beam, and \(p\) for IR beam (ssp). All the spectra were collected at room temperature with an RH of \(\sim\)50%. Nanoindentation tests were performed with a nanoindentation instrument having a Berkovich tip on a nanoindenter at ambient conditions of 22 \({}^{\circ}\)C and 40% RH. The nanoindentation tests were carried out with a continuous stiffness measurement, and the maximum penetration depth was set as 50 nm. More than 20 individual nanoindentation tests at diffident positions were carried out, and the average value and standard error were used to ensure the reproducibility of experiments results. Using an atomic force microscope (AFM), the nanowear tests were conducted with a spherical diamond probe with a curvature radius of 0.54 um and elastic constant of 254 N/m. During the whole tests, the room temperature and humidity were controlled at 22 \({}^{\circ}\)C and 40% RH, respectively. The applied normal load was 60 uN, the sliding speed and distance were 2 um/s and 4 um, respectively, and the reciprocating sliding cycles were set as 100. After the nanowear tests, the nanowear marks were in situ imaged with a silicon nitride tip with a radius of curvature of 10 nm in the tapping mode. The force constant of the tip cantilever was 20 N/m, and the scan area was 3 um \(\times\) 3 um. In order to ensure the repeatability of the experiments, all the wear tests were repeated at least 5 times independently. The Vickers indentation tests were performed using a Vickers hardness tester (HXD-1000 TMC/LCD, Shanghai Taiming Optics Co., Ltd., Shanghai, China). The normal load was set as 0.1 N. The loading time, holding time, and unloading time were 5 s, 15 s, and 5 s, respectively. The room humidity and temperature were 40% RH and 22 \({}^{\circ}\)C, respectively. The Vickers hardness (HV) of various FS surfaces was calculated by [17]:  
\[H_{V}=\frac{(1.8544)(0.102)F}{d^{2}} \tag{1}\]  
where \(d\) is the diagonal length of the residual imprint indentation under a given applied normal load \(F\). To reveal the indentation-induced subsurface damage of FS, all the glass samples after Vickers indentation tests were annealed at 0.9 \(\times\)\(T_{\text{g}}\) (K) for 4 h, and the Vickers indentation marks were re-imaged with AFM.