Journal of Chemical Engineering & Process Technology
Open Access
ISSN: 2157-7048
+44-77-2385-9429
ISSN: 2157-7048
+44-77-2385-9429
Jong-Sung Yu, Apurba Sinhamahapatra and Jong-Pil Jeon
Daegu Gyeongbuk Institute of Science and Technology, South Korea
Scientific Tracks Abstracts: J Chem Eng Process Technol
High efficiency with stable performance and utilization of visible light is a key challenge to sunlight-induced photochemical generation of H2, the cleanest energy carrier. Recently, black TiO2-x materials were achieved by creating oxygen vacancies and/ or defects at the surface using different methods. Fascinatingly, they exhibited an extended absorption in VIS and IR as well as UV light, along with a band gap decrease from 3.2 (anatase) to ~1 eV. However, despite the dramatic enhancement of optical absorption of black TiO2-x material, it fails to show expected visible light-assisted water splitting efficiency. Therefore, a new reduced TiO2 material with optimized properties would be highly desired for visible light photocatalysis. Herein, we report H-doped reduced TiO2-x nanoparticles prepared by a controlled reduction via the simultaneous presence of two active reducing species, [Mg] and [H] in a confined microenvironment at the surface of TiO2. This new material exhibits outstanding activity (31.4 mmolg-1h-1) and excellent stability after Pt deposition for photochemical H2 generation from methanol-water in simulated sunlight. The excellent photoactivity of H:TiO2-x is attributed to the oxygen vacancies and H doping at the TiO2 surface generated by [Mg] and [H]. The photocatalyst works at wavelengths <700 nm and exhibits reasonable visible-light activity with a quantum yield of 17.8, 7.62 and 3.72% at 400, 420 and 454 nm, respectively, along with an exceptionally high turnover number (238680) with respect to Pt. This outstanding activity can be correlated with the extended absorption of visible light, perfect band position, presence of an appropriate amount of Ti3+ and oxygen vacancy and slower charge recombination.
Jong-Sung Yu has earned his BSc in Chemistry from Sogang University in Seoul, South Korea and PhD from the University of Houston in 1990 before Postdoctoral work at Ohio State University. He was a Professor in South Korea University during 2008-2015 and then joined DGIST. Currently, he is a Supervisor for graduate students of Light, Salts and Water Research Lab and a Chairperson at Energy Systems Engineering Department of DGIST, where his research focuses on nanostructured materials, including nanoscale 0-3D materials and their composites and their energy applications for fuel cells, batteries, super-capacitors, sensors and photocatalytic systems.