One-Step Hydrothermal Synthesis of Anatase TiO2 Nanotubes for Efficient Photocatalytic CO2 Reduction

Khaled Alkanad; Abdo Hezam; Nabil Al-Zaqri; Mohammed Abdullah Bajiri; Gubran Alnaggar; Qasem Ahmed Drmosh; Hanadi A Almukhlifi; Lokanath Neratur Krishnappagowda

doi:10.1021/acsomega.2c04211

One-Step Hydrothermal Synthesis of Anatase TiO₂ Nanotubes for Efficient Photocatalytic CO₂ Reduction

ACS Omega. 2022 Oct 18;7(43):38686-38699. doi: 10.1021/acsomega.2c04211. eCollection 2022 Nov 1.

Authors

Khaled Alkanad¹, Abdo Hezam², Nabil Al-Zaqri³, Mohammed Abdullah Bajiri⁴, Gubran Alnaggar⁵, Qasem Ahmed Drmosh⁶, Hanadi A Almukhlifi⁷, Lokanath Neratur Krishnappagowda¹

Affiliations

¹ Department of Studies in Physics, University of Mysore, Manasagangotri, Mysuru570 006, India.
² Leibniz Institute for Catalysis at the University of Rostock, 18059Rostock, Germany.
³ Department of Chemistry, College of Science, King Saud University, PO Box 2455, Riyadh11451, Saudi Arabia.
⁴ Department of Studies and Research in Industrial Chemistry, School of Chemical Sciences, Kuvempu University, Shankaraghatta577 451, India.
⁵ Department of Studies in Chemistry, University of Mysore, Manasagangotri, Mysuru570006, India.
⁶ Interdisciplinary Research Center for Hydrogen and Energy Storage, King Fahd University of Petroleum and Minerals, Dhahran31261, Saudi Arabia.
⁷ Department of Chemistry, Faculty of Science, University of Tabuk, P.O. Box 741, Tabuk47512, Saudi Arabia.

Abstract

The hydrothermal dissolution-recrystallization process is a key step in the crystal structure of titania-based nanotubes and their composition. This work systematically studies the hydrothermal conditions for directly synthesizing anatase TiO₂ nanotubes (ATNTs), which have not been deeply discussed elsewhere. It has been well-known that ATNTs can be synthesized by the calcination of titanate nanotubes. Herein, we found the ATNTs can be directly synthesized by optimizing the reaction temperature and time rather than calcination of titanate nanotubes, where at each temperature, there is a range of reaction times in which ATNTs can be prepared. The effect of NaOH/TiO₂ ratio and starting materials was explored, and it was found that ATNTs can be prepared only if the precursor is anatase TiO₂, using rutile TiO₂ leads to forming titanate nanotubes. As a result, ATNTs produced directly without calcination have excellent photocatalytic CO₂ reduction than titanate nanotubes and ATNTs prepared by titanate calcination.