“…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.…”
Section: Resultsmentioning
confidence: 99%
“…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.…”
Section: Resultsmentioning
confidence: 99%
“…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.…”
Section: Resultsmentioning
confidence: 99%
“…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 .…”
Section: Introductionmentioning
confidence: 99%
“…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.…”
The
growing demand for charming smiles has led to the popularization
of tooth bleaching procedures. Current tooth bleaching products with
high-concentration hydrogen peroxide (HP, 30–40%) are effective
but detrimental due to the increased risk of enamel destruction, tooth
sensitivity, and gingival irritation. Herein, we reported a less-destructive
and efficient tooth whitening strategy with a low-concentration HP,
which was realized by the remarkably enhanced Fenton-like catalytic
activity of oxygen-deficient TiO2 (TiO2–x
). TiO2–x
nanoparticles
were synthesized with a modified solid-state chemical reduction approach
with NaBH4. The Fenton-like activity of TiO2–x
was optimized by manipulating oxygen vacancy (OV)
concentration and further promoted by the near-infrared (NIR)-induced
photothermal effect of TiO2–x
.
The TiO2–x
sample named BT45 was
chosen due to the highest methylene blue (MB) adsorption ability and
Fenton-like activity among acquired samples. The photothermal property
of BT45 under 808 nm NIR irradiation was verified and its enhancement
on Fenton-like activity was also studied. The BT45/HP + NIR group
performed significantly better in tooth whitening than the HP + NIR
group on various discolored teeth (stained by Orange II, tea, or rhodamine
B). Excitingly, the same tooth whitening performance as the Opalescence
Boost, a tooth bleaching product containing 40% HP, was obtained by
a self-produced bleaching gel based on this novel system containing
12% HP. Besides, negligible enamel destruction, safe temperature range,
and good cytocompatibility of TiO2–x
nanoparticles also demonstrated the safety of this tooth bleaching
strategy. This work indicated that the photothermal-enhanced Fenton-like
performance of the TiO2–x
-based
system is highly promising in tooth bleaching application and can
also be extended to other biomedical applications.
“…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.…”
Section: Resultsmentioning
confidence: 99%
“…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.…”
Section: Resultsmentioning
confidence: 99%
“…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.…”
Section: Resultsmentioning
confidence: 99%
“…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 .…”
Section: Introductionmentioning
confidence: 99%
“…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.…”
The
growing demand for charming smiles has led to the popularization
of tooth bleaching procedures. Current tooth bleaching products with
high-concentration hydrogen peroxide (HP, 30–40%) are effective
but detrimental due to the increased risk of enamel destruction, tooth
sensitivity, and gingival irritation. Herein, we reported a less-destructive
and efficient tooth whitening strategy with a low-concentration HP,
which was realized by the remarkably enhanced Fenton-like catalytic
activity of oxygen-deficient TiO2 (TiO2–x
). TiO2–x
nanoparticles
were synthesized with a modified solid-state chemical reduction approach
with NaBH4. The Fenton-like activity of TiO2–x
was optimized by manipulating oxygen vacancy (OV)
concentration and further promoted by the near-infrared (NIR)-induced
photothermal effect of TiO2–x
.
The TiO2–x
sample named BT45 was
chosen due to the highest methylene blue (MB) adsorption ability and
Fenton-like activity among acquired samples. The photothermal property
of BT45 under 808 nm NIR irradiation was verified and its enhancement
on Fenton-like activity was also studied. The BT45/HP + NIR group
performed significantly better in tooth whitening than the HP + NIR
group on various discolored teeth (stained by Orange II, tea, or rhodamine
B). Excitingly, the same tooth whitening performance as the Opalescence
Boost, a tooth bleaching product containing 40% HP, was obtained by
a self-produced bleaching gel based on this novel system containing
12% HP. Besides, negligible enamel destruction, safe temperature range,
and good cytocompatibility of TiO2–x
nanoparticles also demonstrated the safety of this tooth bleaching
strategy. This work indicated that the photothermal-enhanced Fenton-like
performance of the TiO2–x
-based
system is highly promising in tooth bleaching application and can
also be extended to other biomedical applications.
The journey of ceramics in medicine has been synchronized with an evolution from the first generation—alumina, zirconia, etc.—to the third —3D scaffolds. There is an up‐and‐coming member called oxygen‐deficient or colored bioceramics, which have recently found their way through biomedical applications. The oxygen vacancy steers the light absorption toward visible and near infrared regions, making the colored bioceramics multifunctional—therapeutic, diagnostic, and regenerative. Oxygen‐deficient bioceramics are capable of turning light into heat and reactive oxygen species for photothermal and photodynamic therapies, respectively, and concomitantly yield infrared and photoacoustic images. Different types of oxygen‐deficient bioceramics have been recently developed through various synthesis routes. Some of them like TiO2−x, MoO3−x, and WOx have been more investigated for biomedical applications, whereas the rest have yet to be scrutinized. The most prominent advantage of these bioceramics over the other biomaterials is their multifunctionality endowed with a change in the microstructure. There are some challenges ahead of this category discussed at the end of the present review. By shedding light on this recently born bioceramics subcategory, it is believed that the field will undergo a big step further as these platforms are naturally multifunctional.
Hydrogen peroxide (H2O2) as a green oxidizing agent is widely used in various fields. Electrosynthesis of H2O2 has gradually become a hotspot due to its convenient and environmentally friendly features. Single‐atom‐site catalysts (SASCs) with uniform active sites are the ideal catalyst for the in‐depth study of the reaction mechanism and structure‐performance relationship. In this review, we summarize the outstanding achievements of SASCs in the electrosynthesis of H2O2 through 2e− oxygen reduction reaction (ORR) and 2e− water oxygen reaction (WOR) in recent years. Firstly, the elementary steps of the two pathways and the roles of key intermediates (*OOH and *OH) in the reactions are systematically discussed. Next, the influence of the size effect, electronic structure regulation, the support/interfacial effect, the optimization of coordination microenvironments, and the SASCs‐derived catalysts applied in 2e− ORR are systematically analyzed. Besides, the developments of SASCs in 2e− WOR are also overviewed. Finally, the research progress of H2O2 electrosynthesis on SASCs is concluded, and an outlook on the rational design of SASCs is presented in conjunction with the design strategies and characterization techniques.This article is protected by copyright. All rights reserved
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