A novel solar radiation absorption enhancement of TiO2 nanomaterial by a simple hydrogenation method

• Published in: Journal of materials research 2021-05, Vol.36 (10), p.2118-2131
• Main Authors: Abdelmaksoud, M. K., Sayed, Abderrahman, Sayed, Sarah, Abbas, M.
• Format: Article
• Language: English
• Subjects: Anatase; Applied and Technical Physics; Biomaterials; Chemistry and Materials Science; Crystallites; Hydrogenation; Inorganic Chemistry; Low temperature; Materials Engineering; Materials research; Materials Science; Nanomaterials; Nanotechnology; Photoelectrons; Photomicrographs; Radiation; Radiation absorption; Raman spectra; Solar radiation; Spectrum analysis; Titanium; Titanium dioxide; X ray photoelectron spectroscopy
• ISSN: 0884-2914; 2044-5326
• DOI: 10.1557/s43578-021-00263-w

Black titanium dioxide is produced by straightforward hydrogenation of its Anatase white counterpart at a relatively low temperature of 325 °C. X-ray measurements show that the average crystallite size is reduced by 37% due to the hydrogenation process. This decline in crystallite size is further confirmed by the Raman spectra of the inspected samples. Instead, the micrographs of the transmission electron microscope indicate that the average particle size of the black and white titanium dioxide is about 126 ± 45 nm and 109 ± 32 nm, respectively. Moreover, the optical bandgap drops as a result of the hydrogenation, which is explained by the presence of the localized states of Ti 3+ ions and/or oxygen vacancies in hydrogenated TiO 2 as verified by the X-ray photoelectron spectroscopy (XPS) measurements. The black oxide shows significant photothermal properties and a considerable maximum attainable temperature under a continuous solar illumination. Most importantly, the hydrogenated oxide enhances the solar radiation absorption considerably near the optimum solar intensity. Graphic abstract