Nanostructured Graphene-Titanium Dioxide Composites Synthesized by a Single-Step Aerosol Process for Photoreduction of Carbon Dioxide

Abstract

Photocatalytic reduction of carbon dioxide (CO 2 ) to hydrocarbons by using nanostructured materials activated by solar energy is a promising approach to recycling CO 2 as a fuel feedstock. CO 2 photoreduction, however, suffers from low efficiency mainly due to the inherent drawback of fast electron-hole recombination in photocatalysts. This work reports the synthesis of nanostructured composites of titania (TiO 2 ) nanoparticles (NPs) encapsulated by reduced graphene oxide (rGO) nanosheets via an aerosol approach. The role of synthesis temperature and TiO 2 /GO ratio in CO 2 photoreduction was investigated. As-prepared nanocomposites demonstrated enhanced CO 2 conversion performance as compared with that of pristine TiO 2 NPs due to the strong electron trapping capability of the rGO nanosheets.

Crumpled reduced graphene oxide–amine–titanium dioxide nanocomposites for simultaneous carbon dioxide adsorption and photoreduction

“…However, it increased to 1.04 after CO 2 photoreduction, which showed the decrease of defect densities, indicating simultaneous photoreduction of r--GO. This observation is consistent with the trends reported in our previous work on CO 2 photoreduction of CGOTI 31 and is confirmed by our conductivity measurements in Table 2.…”

“…The CO yield, however, decreased with further increases in the TiO 2 /GO percentage after the optimal value (20%). Based on our previous studies, 31,32 TiO 2 /GO percentages beyond 20% increased the possibility of agglomeration of TiO 2 NPs both inside and outside the r--GO nanosheets. The overall CO 2 photoreduction efficiency will be affected by both the interparticle e ----h + recombination due to the agglomeration of TiO 2 NPs inside the r--GO nanosheets, and the intraparticle e ---- h + recombination resulting from free TiO 2 NPs outside the r--GO nanosheets.…”

“…In our recent work, 32 crumpled reduced graphene oxide (CGO)--TiO 2 (CGOTI) nanocomposites was shown to result in a multi--fold enhancement of CO 2 photoreduction performance compared to pure TiO 2 . 31 Another important aspect is the enhancement of the CO 2 adsorption on the surface, and this has not been extensively studied. Amine modification is one of the most commonly applied techniques in this regard.…”

Rational Design of Efficient Semiconductor-based Photocatalysts via Microdroplets: A Review

“…Given all these advantages mentioned above, numerous studies have been carried out to synthesize the CGO/ semiconductor composite photocatalysts (Carraro F. et al, 2015;Jiang Y. et al, 2014;Nie Y. et al, 2016;Wang W.N. et al, 2014).…”

Photocatalytic Reduction of CO2Using TiO2-Graphene Nanocomposites

“…In the previous researches, Wang et al prepared TiO 2 -RGO composite via a single-step aerosol approach, and they also investigated the role of synthesis temperature and TiO 2 /GO ratio in CO 2 photoreduction [8]. Tu Cheng et al provided a photoelectrocatalytic technique for reduction of CO 2 into chemicals [15].…”