TY - JOUR
T1 - Significantly enhanced cocatalyst-free H2 evolution from defect-engineered Brown TiO2
AU - Babu, S. Jagadeesh
AU - Rao, V. Navakoteswara
AU - Murthy, Dharmapura H.K.
AU - Shastri, Mahesh
AU - M, Murthy
AU - Shetty, Manjunath
AU - Raju, K. S.Anantha
AU - Shivaramu, Prasanna D.
AU - Kumar, C. S.Ananda
AU - Shankar, M. V.
AU - Rangappa, Dinesh
N1 - Funding Information:
This work is partially supported by the Dept. of IT, BT & ST, Govt. of Karnataka under grant No. VGST/CESEM/2012-13/182. The authors would like to thank Y. Gambe, I. Honma, Tohoku University, Japan, CeNs Bangalore, CeNSE, IISc Bangalore for INUP program, SAIF Cochin, and SAIF IIT Madras for providing characterization facilities.
Publisher Copyright:
© 2020 Elsevier Ltd and Techna Group S.r.l.
PY - 2021/5/15
Y1 - 2021/5/15
N2 - 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/Ti3+ 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−1g−1cat 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.
AB - 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/Ti3+ 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−1g−1cat 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.
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U2 - 10.1016/j.ceramint.2020.10.026
DO - 10.1016/j.ceramint.2020.10.026
M3 - Article
AN - SCOPUS:85094580154
SN - 0272-8842
VL - 47
SP - 14821
EP - 14828
JO - Ceramics International
JF - Ceramics International
IS - 10
ER -