title: An overview on limitations of TiO2-based particles for photocatalytic degradation of organic pollutants and the corresponding countermeasures.
abstract: The pollutants classified as "persistent organic pollutants (POPs)", are being subject to high concern among the scientific community due to their persistence in the environment. TiO2-based photocatalytic process has shown a great potential as a low-cost, environmentally friendly and sustainable treatment technology to remove POPs in sewage to overcome the shortcomings of the conventional technologies. However, this technology suffers from some main technical barriers that impede its commercialization, i.e., the inefficient exploitation of visible light, low adsorption capacity for hydrophobic contaminants, uniform distribution in aqueous suspension and post-recovery of the TiO2 particles after water treatment. To improve the photocatalytic efficiency of TiO2, many studies have been carried out with the aim of eliminating the limitations mentioned above. This review summarizes the recently developed countermeasures for improving the performance of TiO2-based photocatalytic degradation of organic pollutants with respect to the visible-light photocatalytic activity, adsorption capacity, stability and separability. The performance of various TiO2-based photocatalytic processes for POPs degradation and the underlying mechanisms were summarized and discussed. The future research needs for TiO2-based technology are suggested accordingly. This review will significantly improve our understanding of the process of photocatalytic degradation of POPs by TiO2-based particles and provide useful information to scientists and engineers who work in this field.
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha, Hunan 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha, Hunan 410082, China. Electronic address: dongh@hnu.edu.cn.
authors.forename: Haoran
authors.initials: H
authors.lastname: Dong
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha, Hunan 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha, Hunan 410082, China.
authors.forename: Guangming
authors.initials: G
authors.lastname: Zeng
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha, Hunan 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha, Hunan 410082, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Tang
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha, Hunan 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha, Hunan 410082, China.
authors.forename: Changzheng
authors.initials: C
authors.lastname: Fan
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha, Hunan 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha, Hunan 410082, China.
authors.forename: Chang
authors.initials: C
authors.lastname: Zhang
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha, Hunan 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha, Hunan 410082, China.
authors.forename: Xiaoxiao
authors.initials: X
authors.lastname: He
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha, Hunan 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha, Hunan 410082, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: He
mesh_terms: D000327:Adsorption; D002384:Catalysis; D008027:Light; D009930:Organic Chemicals / Q000737:chemistry / Q000528:radiation effects; D055668:Photochemical Processes; D014025:Titanium / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000528:radiation effects; D018508:Water Purification / Q000379:methods*
chemical_list: D009930:Organic Chemicals; D014874:Water Pollutants, Chemical; C009495:titanium dioxide; D014025:Titanium
keywords: Adsorption; Particle separation; Persistent organic pollutants; Photodegradation; Surface modification