Facile One-Step Route for the Development of in Situ Cocatalyst-Modified Ti3+Self-Doped TiO2for Improved Visible-Light Photocatalytic Activity.
Development of visible-light-driven photocatalysts by employing a relatively simple, efficient, and cost-effective one-step process is essential for commercial applications. Herein, we report for the first time the synthesis of in situ Cu-ion modified Ti3+self-doped rutile TiO2by such a facile one-step solution precursor plasma spray (SPPS) process using a water-soluble titanium precursor. In the SPPS process, Ti3+self-doping on Ti4+of rutile TiO2is found to take place because of electron transfer from the created oxygen vacancies to Ti4+-ions. In situ Cu modification of the above Ti3+self-doped rutile TiO2by additionally introducing a Cu solution into plasma plume is also demonstrated. While the Ti3+self-doping induces broad absorption in the visible-light region, the addition of Cu ion leads to even broader absorption in the visible region owing to resulting synergistic properties. The above materials were evaluated for various self-cleaning photocatalytic applications under visible-light illumination. Cu-ion modified Ti3+self-doped rutile TiO2is noted to exhibit a remarkably enhanced visible-light activity in comparison with Ti3+self-doped rutile TiO2, with the latter itself outperforming commercial TiO2photocatalysts, thereby suggesting the suitability of the material for indoor applications. The broad visible-light absorption by Ti3+self-doping, the holes with strong oxidation power generated in the valence band, and electrons in Ti3+isolated states that are effectively separated into the high reductive sites of Cu ions upon visible-light irradiation, accounts for improved photocatalytic activity. Moreover, the synthesis process (SPPS) provides a valuable alternative to orthodox multistep processes for the preparation of such visible-light-driven photocatalysts.
Centre for Nanomaterials and ‡Centre for Engineered Coatings, International Advanced Research Centre for Powder Metallurgy and New Materials , Hyderabad 500005, India.
Raju
R
Kumar
Centre for Nanomaterials and ‡Centre for Engineered Coatings, International Advanced Research Centre for Powder Metallurgy and New Materials , Hyderabad 500005, India.
Sivakumar
S
Govindarajan
Centre for Nanomaterials and ‡Centre for Engineered Coatings, International Advanced Research Centre for Powder Metallurgy and New Materials , Hyderabad 500005, India.
Reddy Kunda
RK
Siri Kiran Janardhana
Centre for Nanomaterials and ‡Centre for Engineered Coatings, International Advanced Research Centre for Powder Metallurgy and New Materials , Hyderabad 500005, India.
Tata Narasinga
TN
Rao
Centre for Nanomaterials and ‡Centre for Engineered Coatings, International Advanced Research Centre for Powder Metallurgy and New Materials , Hyderabad 500005, India.
Shrikant Vishwanath
SV
Joshi
Centre for Nanomaterials and ‡Centre for Engineered Coatings, International Advanced Research Centre for Powder Metallurgy and New Materials , Hyderabad 500005, India.
Srinivasan
S
Anandan
cocatalyst; rutile TiO2; self-cleaning; self-doping; solution precursor plasma spray; visible-light