Oxygen Deficient TiO2−x with Dual Reaction Sites for Activation of H2O2 to Degrade Organic Pollutants

Photothermal-Enhanced Fenton-like Catalytic Activity of Oxygen-Deficient Nanotitania for Efficient and Safe Tooth Whitening

“…Oxygen vacancy (OV) is the key factor initiating the activation of Fenton-like reaction, so the OV of samples formed in the reduction process was detected by ESR measurements (Figure f) . No ESR signal was detected in the P25 sample, whereas strong OV signals were detected in all of the TiO 2– x samples and their intensities grew with the chemical reduction level . Besides the OV formation, TiO 2– x samples also acquired dramatically enhanced visible and NIR light absorption (Figure g), in which the BT15 exhibited relatively lower light absorption ability.…”

“…Furthermore, degradation results of high-concentration MB (80 ppm) and RhB (100 ppm) further confirmed the strong adsorption ability and Fenton-like activity of BT45 (Figure S3). Although OV serves as the “Fenton-catalytic” center, the Fenton-like catalytic performance of TiO 2– x is also influenced by the adsorption ability, which could facilitate the affinity to HP molecules and pollutants, resulting in faster • OH formation and organics degradation. , BT60 with the highest OV concentration performed inferior to the BT45 sample in Fenton-like catalytic performance, which could be explained by the decreased reaction sites caused by nanoparticles aggregation and weaker MB adsorption ability. Consequently, BT45 with the strongest adsorption capacity and Fenton-like activity in this study was chosen for the following experiments.…”

“…37 No ESR signal was detected in the P25 sample, whereas strong OV signals were detected in all of the TiO 2−x samples and their intensities grew with the chemical reduction level. 33 Besides the OV formation, TiO 2−x samples also acquired dramatically enhanced visible and NIR light absorption (Figure 2g), in which the BT15 exhibited relatively lower light absorption ability. The lifted NIR adsorption of TiO 2−x samples laid the foundation for NIRinduced photothermal conversion ability.…”

“…Titania has been widely applied in biomedicine owing to its chemical stability, biocompatibility, low cost, and adjustable properties. , Oxygen-deficient titania (TiO 2– x ), derived from titania and characterized with broadband optical absorbance from the near-infrared (NIR) to the ultraviolet, has acquired greatly extended application potential in biomedicine lately. , Recently, in advanced water treatment fields, TiO 2– x was used as a Fenton-like agent with a wider pH working window (pH = 2–9) compared to the traditional Fenton catalysts . Furthermore, the presence of more oxygen vacancy (OV) on TiO 2– x could efficiently strengthen its Fenton-like catalytic performance and dye adsorption capacity . Besides, TiO 2– x also acts as an excellent near-infrared responsive photothermal agent in tumor photothermal therapy .…”

“…13 Furthermore, the presence of more oxygen vacancy (OV) on TiO 2−x could efficiently strengthen its Fenton-like catalytic performance and dye adsorption capacity. 33 Besides, TiO 2−x also acts as an excellent nearinfrared responsive photothermal agent in tumor photothermal therapy. 32 According to classical thermodynamic molecular collision theory, a temperature increase may be a feasible method to promote the Fenton-like reaction, 34,35 potentially leading to greatly improved bleaching efficacy under an acceptable temperature of the dental pulp tissue.…”