One-Pot Self-Assembled Three-Dimensional TiO₂-Graphene Hydrogel with Improved Adsorption Capacities and Photocatalytic and Electrochemical Activities

Abstract

We reported the development of a new type of multifunctional titanium dioxide (TiO2)-graphene nanocomposite hydrogel (TGH) by a facile one-pot hydrothermal approach and explored its environmental and energy applications as photocatalyst, reusable adsorbents, and supercapacitor. During the hydrothermal reaction, the graphene nanosheets and TiO2 nanoparticles self-assembled into three-dimensional (3D) interconnected networks, in which the spherical nanostructured TiO2 nanoparticles with uniform size were densely anchored onto the graphene nanosheets. We have shown that the resultant TGH displayed the synergistic effects of the assembled graphene nanosheets and TiO2 nanoparticles and therefore exhibited a unique collection of physical and chemical properties such as increased adsorption capacities, enhanced photocatalytic activities, and improved electrochemical capacitive performance in comparison with pristine graphene hydrogel and TiO2 nanoparticles. These features collectively demonstrated the potential of 3D TGH as an attractive macroscopic device for versatile applications in environmental and energy storage issues.

Removal of Cr(VI) by 3D TiO 2 -graphene hydrogel via adsorption enriched with photocatalytic reduction

“…The qm values of the samples containing 20%, 40%, 60%, and 80% TiO2 were determined as 5.60, 6.01, 7.89, and 13.09 mg/g, higher than that of rGH (5.03 mg/g). In TiO2-rGH, the TiO2 nanoparticles effectively prevented the aggregation of the GO sheets, which influenced the growth of the 3D TiO2-rGH structure [35] , and thus improved the surface area of rGO. Another key factor in generating the adsorption capacity of TiO2-rGH is the graphene π-π interactions, which reduced the competitive adsorption of water [36] .…”

Programmable Nanocarbon‐Based Architectures for Flexible Supercapacitors

“…[ 189,192,196,197 ] Apart from MnO 2 , other transition metal oxides also exhibit the capacity of enhancing the specifi c capacitance of graphenebased SC electrodes, as shown in Figure 8 i. [198][199][200] For example, ZnO with tailoring nanostructures can easily grow on various substrates, especially on graphene fi lms. The nanostructured ZnO often show pseudo-capacitance behavior.…”

A Cu–m-phenylenediamine complex induced route to fabricate poly(m-phenylenediamine)/reduced graphene oxide hydrogel and its adsorption application

“…Despite the excellent prospects, G-gel still lacks superior chemical activity due to the deficiency of functional sites, which is not beneficial for its versatile application, typically the water purification [6][7][8][9][10][11]. It has been reported that the crosslinking of polymer with graphene produced functionalized G-gel, which is superior for water purification, such as poly(vinyl alcohol)/G-gel and poly(dopamine)/G-gel [12][13][14][15][16].…”