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

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.

The Photocatalytic Conversion of Carbon Dioxide to Fuels Using Titanium Dioxide Nanosheets/Graphene Oxide Heterostructure as Photocatalyst

“…To our knowledge, we are the first to report acetone vapor as a product of gas–phase CO 2 photoreduction. Alkanad and his team [ 23 ] synthesized anatase TiO 2 nanotubes using a one–step hydrothermal technique and utilized them for CO 2 photoreduction. The nanotubes were illuminated by a 300 Watts Xenon lamp (Xe), yielding only methane at an unprecedented production rate of 47 mol g cat −1 h −1 .…”

“…A hard template synthesis involves using rigid porous materials that control the growth of the nanostructures, while a soft template synthesis utilizes chemicals that provide intermolecular interactions with a precursor. Various soft templates, such as sodium hydroxide (NaOH), potassium hydroxide (KOH) and hydrofluoric acid (HF), were demonstrated for the synthesis of TiO 2 nanorods [ 22 ], nanotubes [ 23 ], nanoribbon [ 12 ] and nanosheets [ 20 , 21 ]. The nanostructures provide high surface activity and a high surface–to–volume ratio, which amplifies the photoactivity of TiO 2 .…”

Advances and Perspectives of Titanium-Based Nanocomposites for Energy Generation and Environmental Remediation Applications: A Review

“…Important research carried out by Alkanad et al showed the one-step hydrothermal synthesis of anatase TiO 2 nanotubes, using chemicals such as sodium hydroxide, titanium oxide, and other various precursors. 26 Usually, the major chemicals used for hydrothermal methods are titanium isopropoxide, ethanol, sodium hydroxide, isopropanol, and acetic acid, and the entire reaction is carried out in a Teflon lined autoclave. The obtained morphologies of TiO 2 are like nanowires (Figure 2b), nanoparticles (Figure 2c), nanocuboids (Figure 2d), nanorods (Figure 2e), etc.…”

“…Thus, the hydrothermal method provides a simple and economic way of preparing a highly active and promising catalyst for the production of hydrogen gas. Important research carried out by Alkanad et al showed the one-step hydrothermal synthesis of anatase TiO 2 nanotubes, using chemicals such as sodium hydroxide, titanium oxide, and other various precursors . Usually, the major chemicals used for hydrothermal methods are titanium isopropoxide, ethanol, sodium hydroxide, isopropanol, and acetic acid, and the entire reaction is carried out in a Teflon lined autoclave.…”

Ultrahigh-acetone-sensitivity sensor based on Pt-loaded TiO2 porous nanoparticles synthesized via a facile hydrothermal method

“…Yang et al successfully improved a SnO 2 methane gas sensor by adding Pt NPs [31]. Pt-modified α-Fe 2 O 3 prepared by Liu et al exhibited excellent gas-sensing performance for acetone [32]. Generally, few straightforward one-step experiments have been conducted, and most Ptmodified TiO 2 NPs have been generated in a stepwise fashion.…”