Separation-free TiO2-graphene hydrogel with 3D network structure for efficient photoelectrocatalytic mineralization

Herein, TiO2-graphene hydrogel (TGH) electrodes with 3D network structure were designed and fabricated successfully via the one-pot method and the photoelectrocatalytic mineralization ability over TGH electrodes was studied in a dynamic system. TGH electrodes showed interconnected open-framework and large specific surface area, which greatly improved the adsorption capacity for organic pollutants. Most interestingly, TGH electrodes exhibited remarkably superior photoelectrocatalytic degradation activity for MB and phenol, the removal rate was 3 times higher than that of P25. In this process, strong oxidizing h(+)' and (OH)-O-center dot radicals worked as the main active groups, contributed to the deep mineralization ability for organic pollutants over TGH electrodes. The efficient photoelectrocatalytic mineralization ability of TGH electrodes should mainly benefit from the synergism between adsorption-enrichment and in-situ photoelectrocatalytic oxidation, and the extremely fast transfer for photogenerated electrons on graphene hydrogel. Besides, TGH electrodes not only took advantage of the efficient activity of nano-photocatalysts, but also possessed the separation-free feature. Overall, a facile route to construct 3D network-structure hydrogels with efficient photoelectrocatalytic mineralization ability was revealed and can potentially be utilized in water purification. (C) 2017 Elsevier B.V. All rights reserved.