{"title":"TiO2纳米结构的相变和带隙调制增强可见光活性和环境应用。","authors":"Rajwali Khan, Nasir Rahman, Adhimoorthy Prasannan, Khayriniso Ganiyeva, Sabyasachi Chakrabortty, Sambasivam Sangaraju","doi":"10.1038/s41598-025-07000-x","DOIUrl":null,"url":null,"abstract":"<p><p>Due to its wide-ranging applications in the climate and energy fields, enhancing the visible-light photoactivity of TiO<sub>2</sub> nanoparticles remains a crucial challenge in photocatalysis. Interestingly, this work examined the phase transition, structural, optical, and photocatalytic characteristics of TiO<sub>2</sub> nanoparticles doped with Al<sup>3</sup>⁺/Al<sup>2</sup>⁺ and S⁶⁺ ions. It was observed that the anatase phase (AP) dominates in pure TiO<sub>2</sub> (100%) nanoparticles, whereas the rutile phase (RP) content increases in doped samples, reaching 20 ± 2.1% for X1 (Al = 2%, S = 2%) and falling to 12 ± 1.2% in X4 (Al = 2%, S = 8%). The introduction of Al<sup>3</sup>⁺/Al<sup>2</sup>⁺ and S⁶⁺ induces oxygen vacancies (Ovs) and alters the phase stability, as evidenced by the reduction of transformation energy to - 0.033 eV, facilitating the AP to RP transition. The effective integration of dopants indicates that a redshift and intensity in the Photoluminescence spectrum reduced by X-series nanoparticles is due to band gap reductions (from 3.23 eV for pure TiO<sub>2</sub> to 1.98 eV for X4) and distortions in the lattice generated by Al/S doping. Raman spectroscopy results show peak broadening and shifts due to lattice strain from dopants, which validates dopant incorporation via peak shifts in Fourier-transform infrared spectroscopy. ESR study reveals paramagnetic centers in Ti<sup>3</sup>⁺-Ovs complexes, indicating defect-induced magnetic characteristics. When methylene blue (MB) dye is photocatalyzed under visible light exhibits increased activity and degradation efficiencies that are higher than pure TiO<sub>2</sub>. The pseudo-first-order kinetic results show that co-doping effectively improves photocatalytic activity. Rate constants of 0.017 min⁻<sup>1</sup> for X4 are found to be much higher than 7.28 × 10⁻<sup>4</sup> min⁻<sup>1</sup> for pure TiO<sub>2</sub> nanoparticles. Finally, anatase X-series samples degraded MB at a maximum rate of 96.4% in 150 min, outperforming undoped TiO<sub>2</sub> (15%) and rutile-TiO<sub>2</sub> nanoparticles (65% degradation). The fundamental mechanism explains that the photocatalytic characteristics of TiO<sub>2</sub> are modulated by co-doping, which is why these compounds are potential candidates for environmental remediation applications.</p>","PeriodicalId":21811,"journal":{"name":"Scientific Reports","volume":"15 1","pages":"20309"},"PeriodicalIF":3.9000,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12202806/pdf/","citationCount":"0","resultStr":"{\"title\":\"Phase transition and bandgap modulation in TiO<sub>2</sub> nanostructures for enhanced visible-light activity and environmental applications.\",\"authors\":\"Rajwali Khan, Nasir Rahman, Adhimoorthy Prasannan, Khayriniso Ganiyeva, Sabyasachi Chakrabortty, Sambasivam Sangaraju\",\"doi\":\"10.1038/s41598-025-07000-x\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>Due to its wide-ranging applications in the climate and energy fields, enhancing the visible-light photoactivity of TiO<sub>2</sub> nanoparticles remains a crucial challenge in photocatalysis. Interestingly, this work examined the phase transition, structural, optical, and photocatalytic characteristics of TiO<sub>2</sub> nanoparticles doped with Al<sup>3</sup>⁺/Al<sup>2</sup>⁺ and S⁶⁺ ions. It was observed that the anatase phase (AP) dominates in pure TiO<sub>2</sub> (100%) nanoparticles, whereas the rutile phase (RP) content increases in doped samples, reaching 20 ± 2.1% for X1 (Al = 2%, S = 2%) and falling to 12 ± 1.2% in X4 (Al = 2%, S = 8%). The introduction of Al<sup>3</sup>⁺/Al<sup>2</sup>⁺ and S⁶⁺ induces oxygen vacancies (Ovs) and alters the phase stability, as evidenced by the reduction of transformation energy to - 0.033 eV, facilitating the AP to RP transition. The effective integration of dopants indicates that a redshift and intensity in the Photoluminescence spectrum reduced by X-series nanoparticles is due to band gap reductions (from 3.23 eV for pure TiO<sub>2</sub> to 1.98 eV for X4) and distortions in the lattice generated by Al/S doping. Raman spectroscopy results show peak broadening and shifts due to lattice strain from dopants, which validates dopant incorporation via peak shifts in Fourier-transform infrared spectroscopy. ESR study reveals paramagnetic centers in Ti<sup>3</sup>⁺-Ovs complexes, indicating defect-induced magnetic characteristics. When methylene blue (MB) dye is photocatalyzed under visible light exhibits increased activity and degradation efficiencies that are higher than pure TiO<sub>2</sub>. The pseudo-first-order kinetic results show that co-doping effectively improves photocatalytic activity. Rate constants of 0.017 min⁻<sup>1</sup> for X4 are found to be much higher than 7.28 × 10⁻<sup>4</sup> min⁻<sup>1</sup> for pure TiO<sub>2</sub> nanoparticles. Finally, anatase X-series samples degraded MB at a maximum rate of 96.4% in 150 min, outperforming undoped TiO<sub>2</sub> (15%) and rutile-TiO<sub>2</sub> nanoparticles (65% degradation). The fundamental mechanism explains that the photocatalytic characteristics of TiO<sub>2</sub> are modulated by co-doping, which is why these compounds are potential candidates for environmental remediation applications.</p>\",\"PeriodicalId\":21811,\"journal\":{\"name\":\"Scientific Reports\",\"volume\":\"15 1\",\"pages\":\"20309\"},\"PeriodicalIF\":3.9000,\"publicationDate\":\"2025-06-26\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12202806/pdf/\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Scientific Reports\",\"FirstCategoryId\":\"103\",\"ListUrlMain\":\"https://doi.org/10.1038/s41598-025-07000-x\",\"RegionNum\":2,\"RegionCategory\":\"综合性期刊\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"MULTIDISCIPLINARY SCIENCES\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Scientific Reports","FirstCategoryId":"103","ListUrlMain":"https://doi.org/10.1038/s41598-025-07000-x","RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MULTIDISCIPLINARY SCIENCES","Score":null,"Total":0}
Phase transition and bandgap modulation in TiO2 nanostructures for enhanced visible-light activity and environmental applications.
Due to its wide-ranging applications in the climate and energy fields, enhancing the visible-light photoactivity of TiO2 nanoparticles remains a crucial challenge in photocatalysis. Interestingly, this work examined the phase transition, structural, optical, and photocatalytic characteristics of TiO2 nanoparticles doped with Al3⁺/Al2⁺ and S⁶⁺ ions. It was observed that the anatase phase (AP) dominates in pure TiO2 (100%) nanoparticles, whereas the rutile phase (RP) content increases in doped samples, reaching 20 ± 2.1% for X1 (Al = 2%, S = 2%) and falling to 12 ± 1.2% in X4 (Al = 2%, S = 8%). The introduction of Al3⁺/Al2⁺ and S⁶⁺ induces oxygen vacancies (Ovs) and alters the phase stability, as evidenced by the reduction of transformation energy to - 0.033 eV, facilitating the AP to RP transition. The effective integration of dopants indicates that a redshift and intensity in the Photoluminescence spectrum reduced by X-series nanoparticles is due to band gap reductions (from 3.23 eV for pure TiO2 to 1.98 eV for X4) and distortions in the lattice generated by Al/S doping. Raman spectroscopy results show peak broadening and shifts due to lattice strain from dopants, which validates dopant incorporation via peak shifts in Fourier-transform infrared spectroscopy. ESR study reveals paramagnetic centers in Ti3⁺-Ovs complexes, indicating defect-induced magnetic characteristics. When methylene blue (MB) dye is photocatalyzed under visible light exhibits increased activity and degradation efficiencies that are higher than pure TiO2. The pseudo-first-order kinetic results show that co-doping effectively improves photocatalytic activity. Rate constants of 0.017 min⁻1 for X4 are found to be much higher than 7.28 × 10⁻4 min⁻1 for pure TiO2 nanoparticles. Finally, anatase X-series samples degraded MB at a maximum rate of 96.4% in 150 min, outperforming undoped TiO2 (15%) and rutile-TiO2 nanoparticles (65% degradation). The fundamental mechanism explains that the photocatalytic characteristics of TiO2 are modulated by co-doping, which is why these compounds are potential candidates for environmental remediation applications.
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