Photocatalytic Carbon Dioxide Conversion by Structurally and Materially Modified Titanium Dioxide Nanostructures

Abstract

TiO2 has aroused considerable attentions as a promising photocatalytic material for decades due to its superior material properties in several fields such as energy and environment. However, the main dilemmas are its wide bandgap (3–3.2 eV), that restricts the light absorption in limited light wavelength region, and the comparatively high charge carrier recombination rate of TiO2, is a hurdle for efficient photocatalytic CO2 conversion. To tackle these problems, lots of researches have been implemented relating to structural and material modification to improve their material, optical, and electrical properties for more efficient photocatalytic CO2 conversion. Recent studies illustrate that crystal facet engineering could broaden the performance of the photocatalysts. As same as for nanostructures which have advantages such as improved light absorption, high surface area, directional charge transport, and efficient charge separation. Moreover, strategies such as doping, junction formation, and hydrogenation have resulted in a promoted photocatalytic performance. Such strategies can markedly change the electronic structure that lies behind the enhancement of the solar spectrum harnessing. In this review, we summarize the works that have been carried out for the enhancement of photocatalytic CO2 conversion by material and structural modification of TiO2 and TiO2-based photocatalytic system. Moreover, we discuss several strategies for synthesis and design of TiO2 photocatalysts for efficient CO2 conversion by nanostructure, structure design of photocatalysts, and material modification.

Crystal Design and Photoactivity of TiO2 Nanorod Template Decorated with Nanostructured Bi2S3 Visible Light Sensitizer

“…This is consistent with the feature of optical absorption spectra for Bi 2 S 3 nanorod/TiO 2 nanoplate composites [ 24 ]. Moreover, in the previous TiO 2 /Bi 2 S 3 core–shell nanowire arrays synthesized via a successive ionic layer adsorption and reaction method, the absorption of the composite extends to cover the visible light range, and the decoration of Bi 2 S 3 phase increases the light absorption ability of the pristine TiO 2 nanowires [ 8 ]. Notably, the band gap energies of the pristine TiO 2 and Bi 2 S 3 are evaluated in Figure 9 b,c, respectively, from Tauc plots based on Kubelka–Munk function [ 25 ].…”

“…However, the wide band gap nature of TiO 2 engenders poor response to visible light [ 6 , 7 ]. In order to improve the photoactivity of TiO 2 , the strategy of semiconductor coupling is often used to enhance the solar energy conversion and utilization of TiO 2 [ 8 ]. Several cases of TiO 2 coupled with a visible light sensitizer has been shown a promising approach to improve solar energy utilization efficiency.…”

Mechanistic Understanding in Manipulating Energetics of TiO2 for Photocatalysis

“…Another major application is the remediation of CO 2 and other organics to obtain fuels and valuable chemicals . Many major challenges remain toward the development of economically feasible technologies for solar photocatalysis and CO 2 conversion by TiO 2 -based materials . An alternative approach to utilizing pure TiO 2 could be metal oxide nanocrystal co-catalysts on TiO 2 surfaces to enhance the photocatalytic activity.…”

“…191−194 195 Many major challenges remain toward the development of economically feasible technologies for solar photocatalysis and CO 2 conversion by TiO 2 -based materials. 196 An alternative approach to utilizing pure TiO 2 could be metal oxide nanocrystal co-catalysts on TiO 2 surfaces to enhance the photocatalytic activity. The metal oxide co-catalyst on the TiO 2 surface can collect the photoexcited holes from the valence band of TiO 2 and provide a catalytic site for water oxidation.…”

Highly hydrophilic and dispersed TiO2 nano-system with enhanced photocatalytic antibacterial activities and accelerated tissue regeneration under visible light

“…The modification of TiO 2 with carbon holds considerable promise owing to the great chemical stability, cost-effectiveness, and electronic acceptor properties of carbonaceous materials [ 18 ]. When exposed to light, the modified material can transfer electrons to the conduction band, thereby broadening the absorption range to the visible light region and improving the light absorption capacity [ 19 ].…”