Significantly enhanced cocatalyst-free H2 evolution from defect-engineered Brown TiO2. Issue 10 (15th May 2021)

• Record Type: Journal Article
• Authors: Babu, S. Jagadeesh; Rao, V. Navakoteswara; Murthy, Dharmapura H.K.; Shastri, Mahesh; M, Murthy; Shetty, Manjunath; Raju, K.S. Anantha; Shivaramu, Prasanna D.; Kumar, C.S. Ananda; Shankar, M.V.; Rangappa, Dinesh
• Is Part Of: Ceramics international. Volume 47:Issue 10(2021)Part B
• Page Start: 14821
• Page End: 14828
• Publication Date: 2021-05-15
• Subjects: Brown TiO2 -- Defects -- Photocatalyst -- Oxygen vacancy -- Solar hydrogen generation; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2020.10.026
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: TiO2 is the extensively investigated materials for various photocatalytic reforming and water splitting. Superior stability towards photo-corrosion, appropriate band energy levels driving most photocatalytic reactions, and low-cost production are promising features of TiO2 . However, a primary limitation with TiO2 is that it only absorbs ultraviolet light constituting less than 5% of the solar spectrum. In this work, we use a facile, low temperature, vacuum-free, and solution-route synthesis approach to rationally induce oxygen vacancy/Ti 3+ defects to reduce the bandgap of TiO2 to 2.0 eV (3.2 eV for pristine white TiO2 ) to form brown TiO2 with enhanced visible-light absorption. The mechanism of defect formation is systematically deduced from the detailed investigation through Raman spectroscopy, spin-sensitive technique, high-resolution microscopy, and surface analysis. The brown TiO2 yielded 8.1 mmol h −1 g −1 cat H2 evolution without any cocatalyst under natural sunlight, which is a factor two higher than pristine (white) TiO2 . To the best of our knowledge, the observed H2 evolution rate is the highest reported value under natural sunlight for any TiO2 -based photocatalyst. This work demonstrates the applicability of brown TiO2 to fabricate large-area photocatalyst panels for the cost-effective production of solar H2 .