title: Synthesis of mesoporous sulfur-doped Ta2O5 nanocomposites and their photocatalytic activities.
abstract: Mesoporous sulfur (S)-doped Ta2O5 nanocomposites have been synthesized for the first time through the sol-gel reaction of tantalum chloride and thiourea in the presence of a F127 triblock copolymer as structure directing agent. The as-formed mesophase S-doped Ta2O5 hybrid gels were calcined at 700°C for 4h to obtain mesoporous S-Ta2O5 nanocomposites. The experimental results indicated that the surface area of the S-doped Ta2O5 was up to 50m(2)g(-1) and the pore diameter was controllable in the range of 3-7.7nm. The S-doped Ta2O5 nanocomposites behave as superior visible light-sensitive photocatalysts and the 1.5at.% S-doped Ta2O5 (S1.5) photocatalyst exhibited excellent photocatalytic activity of ∼92% for the photodegradation of methylene blue, identical to 80% TOC removal after three hours illumination under visible light. The photodegradation rate of S1.5 photocatalyst showed 3.4 times higher than the undoped Ta2O5 due to their narrow bandgap, large surface area, mesostructure and well crystalline state. The S1.5 photocatalyst could be recycled at least five times without an apparent decrease in its photocatalytic efficiency, indicating its high stability for practical applications. To the best of our knowledge, this is the first report that demonstrates one-step synthesis of mesoporous S-doped Ta2O5 nanocomposites as an efficient photocatalysts under visible light illumination.
authors.affiliation: Advanced Materials and Nano-Research Centre, Najran University, P.O. Box: 1988, Najran 11001, Saudi Arabia; Central Metallurgical Research and Development Institute (CMRDI), P.O. Box: 87 Helwan, Cairo 11421, Egypt. Electronic address: adelali141@yahoo.com.
authors.forename: Adel A
authors.initials: AA
authors.lastname: Ismail
authors.affiliation: Advanced Materials and Nano-Research Centre, Najran University, P.O. Box: 1988, Najran 11001, Saudi Arabia.
authors.forename: M
authors.initials: M
authors.lastname: Faisal
authors.affiliation: Advanced Materials and Nano-Research Centre, Najran University, P.O. Box: 1988, Najran 11001, Saudi Arabia; Central Metallurgical Research and Development Institute (CMRDI), P.O. Box: 87 Helwan, Cairo 11421, Egypt.
authors.forename: Farid A
authors.initials: FA
authors.lastname: Harraz
authors.affiliation: Advanced Materials and Nano-Research Centre, Najran University, P.O. Box: 1988, Najran 11001, Saudi Arabia; Department of Physics, College of Science and Arts, Najran University, Saudi Arabia.
authors.forename: A
authors.initials: A
authors.lastname: Al-Hajry
authors.affiliation: Research Center for Advanced Materials Science, King Khalid University, Abha, Saudi Arabia.
authors.forename: A G
authors.initials: AG
authors.lastname: Al-Sehemi
keywords: Mesoporous; Nanocomposites; Photocatalyst; S-doped Ta(2)O(5); Visible light