Graphene Complex Photoelectrocatalysis Behavior Research

As an efficient and green purification method,semiconductor photoelectrocatalysis has the advantages of high efficiency,non-toxicity and easy recycling.It shows great advantages in the treatment of degrading pollutants.At present,the most typical representative of the photoelectrocatalyst is a membrane electrode and a Ti-based array electrode.However,the existing photoelectrode has the disadvantages of poor conductivity and low load.As a member of the emerging carbon family,graphene attracts a growing number of attentions due to its various physicochemical properties.However,graphene performance is not fully utilized.The three-dimensional?3D?hydrogel electrode of titanium dioxide?TiO₂?-graphene was successfully fabricated by a simple one-pot method for the first time,and the adsorption and adsorption-photoelectrocatalytic ability of low-concentration bisphenol A?BPA?was studied on this electrode.Combined with the unique adsorption of graphene and the effective photoelectrocatalytic performance of TiO₂,organic pollutants are rapidly enriched and effectively degraded in situ.Compared with TiO₂-rGO thin film electrode,the hydrogel electrode has higher specific surface area and more reaction sites.The BPA degradation of TiO₂-rGO thin film electrode was 40%after 4 h of ultraviolet irradiation,whereas the removal rate of BPA over the same mass of TiO₂-rGH electrode rate was up to 96%.At the same time,the Ti O₂-rGH electrode can quickly be removed from the product without filtering due to its special macro-3D network structure.In order to further promote the electron-hole separation of TiO₂,g-C₃N₄ with a large conjugated?bond was combined.The morphology and interface properties of the photoelectrocatalysts were characterized by SEM,XRD and XPS.The results showed that the best photocurrent of 7%g-C₃N₄-TiO₂-rGH was 3.75 times than that of TiO₂-rGH,and the 7%g-C₃N₄-TiO₂-rGH could completely decompose phenol at 80 min.The hydrogel electrode has the characteristics of self-regeneration and self-separation,exhibits excellent catalytic activity for BPA and phenol,and achieves the synergistic degradation by adsorption-photoelectrocatalysis.