title: Tricrystalline TiO2 with enhanced photocatalytic activity and durability for removing volatile organic compounds from indoor air.
abstract: It is important to develop efficient and economic techniques for removing volatile organic compounds (VOCs) in indoor air. Heterogeneous TiO2-based semiconductors are a promising technology for achieving this goal. Anatase/brookite/rutile tricrystalline TiO2 with mesoporous structure was synthesized by a low-temperature hydrothermal route in the presence of HNO3. The obtained samples were characterized by X-ray diffraction and N2 adsorption-desorption isotherm. The photocatalytic activity was evaluated by photocatalytic decomposition of toluene in air under UV light illumination. The results show that tricrystalline TiO2 exhibited higher photocatalytic activity and durability toward gaseous toluene than bicrystalline TiO2, due to the synergistic effects of high surface area, uniform mesoporous structure and junctions among mixed phases. The tricrystalline TiO2 prepared at RHNO3=0.8, containing 80.7% anatase, 15.6% brookite and 3.7% rutile, exhibited the highest photocatalytic activity, about 3.85-fold higher than that of P25. The high activity did not significantly degrade even after five reuse cycles. In conclusion, it is expected that our study regarding gas-phase degradation of toluene over tricrystalline TiO2 will enrich the chemistry of the TiO2-based materials as photocatalysts for environmental remediation and stimulate further research interest on this intriguing topic.
authors.affiliation: Department of Environmental Science, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou 310058, China.
authors.forename: Kunyang
authors.initials: K
authors.lastname: Chen
authors.affiliation: Department of Environmental Science, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou 310058, China. Electronic address: zlz@zju.edu.cn.
authors.forename: Lizhong
authors.initials: L
authors.lastname: Zhu
authors.affiliation: Department of Environmental Science, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou 310058, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Yang
mesh_terms: D000393:Air Pollutants / Q000302:isolation & purification* / Q000528:radiation effects; D016902:Air Pollution, Indoor / Q000032:analysis*; D002384:Catalysis; D003460:Crystallization; D052918:Environmental Restoration and Remediation; D010084:Oxidation-Reduction; D055668:Photochemical Processes; D014025:Titanium / Q000737:chemistry*; D014050:Toluene / Q000302:isolation & purification; D014466:Ultraviolet Rays; D055549:Volatile Organic Compounds / Q000302:isolation & purification* / Q000528:radiation effects
chemical_list: D000393:Air Pollutants; D055549:Volatile Organic Compounds; C009495:titanium dioxide; D014050:Toluene; D014025:Titanium
keywords: Gaseous; Mesoporous; Nanomaterials; Photocatalysis; Tricrystalline TiO(2); VOC