Multifunctional TiO2/g-C3N4/Ag nanorod array film as a powerful substrate for surface-enhanced Raman scattering detection and green degradation

Organic pollutants in wastewater have attracted much interest due to their potential threats to the environment and human health. Herein, a reasonably designed multifunctional TiO2/g-C3N4/Ag (TCA) film with the intrinsic Raman signals has been exploited, which exhibits prominent surface-enhanced Raman scattering (SERS) sensitivity, photocatalytic activity, and photoelectrochemical (PEC) conversion performance. For Rhodamine 6G (R6G) as probe molecules, the detection limit of TCA reaches 10-12 M and the SERS enhancement factor is up to 4.94 x 105. The relative standard deviation (RSD) of Raman vibration near 1650 cm-1 is about 6.79%, which proves the good uniformity of the TCA substrate. Meanwhile, the TCA film exhibits excellent photocatalytic and PEC performance with the largest photodegradation rate of 64.95% and the biggest transient photocurrent of 225.89 mu A/cm2 compared with other samples. In addition, TCA also showed good self-cleaning and reusable performance under simulated sunlight irradiation. The excellent multifunction of TCA mainly originates from the synergistic effect of TiO2, g-C3N4, and Ag, including the increased specific surface area, enhanced active sites, and promoted photogenerated charge separation and transportation. These facts manifest that the TCA film can be used for quantitative monitoring and facile decomposing of R6G.