Fig. 1. Experimental flowchart

Fig. 2. SEM images under different UV irradiation time. (a) 5 min; (b) 10 min; (c) 15 min; (d) 20 min; (e) 30 min

Fig. 3. XRD diffraction peaks of TiO₂/Ag and TiO₂

Fig. 4. XPS spectra of TiO₂/Ag and TiO₂. (a) Survey; (b) Ag3d; (c) Ti2p; (d) O1s

Fig. 5. UV-VIS absorption spectra of TiO₂/Ag and TiO₂

Fig. 6. SERS spectra of TiO₂/Ag. (a) SERS spectra under different illumination time; (b) detection results of different R6G concentrations under 10 min of UV irradiation; (c) large-area multi-point Raman spectroscopy test results; (d) RSD at 611 cm^-1; (e) comparison of Raman signals of 10^-6 mol/L R6G under different substrates; (f) comparison of Raman signals of 10^-6 mol/L CV under different substrates

Fig. 7. SERS spectra of TiO₂/Ag. (a) SERS spectra of R6G with 5 self-cleaning cycles at concentration of 10^-6 mol·L^-1; (b) Raman intensity at 1650 cm^-1 during self-cleaning cycle

Fig. 8. Schematic of electromagnetic field simulation of different structures. (a) Electromagnetic effects between individual titanium dioxide and silver; (b) electromagnetic effect between two titanium dioxide

Fig. 9. Schematic of charge transfer process of TiO₂/Ag structure