A novel Ga(Ⅲ)coordination complex as an efficient sensitizer for enhancing photocatalytic activity of TiO_(2)/rGO nanocomposite

Narrow solar-light response range and rapid charges recombination are the main technical barriers in TiO_(2) photocatalysis technology.To overcome these restrictions,in this work we synthesized a novel binuclear gadolinium(Ⅲ) coordination complex,[Gd_(2)(DPDB)_6(DMF)_6(H_(2)O_()2)](DPDB=[(4-dimethylamino)phenyldiazenyl] benzenesulfonate),which was used as an inorganic sensitizer for boosting the visible light-harvesting and quantum efficiency of TiO_(2) supported-reduced graphene oxide(rGO) nanocomposite.Crystal structure of [Gd_(2)(DPDB)_6(DMF)_6(H_(2)O)_(2)](Gd-CMP) was determined from single-crystal X-ray diffraction data,which indicates three-dimensional(3D) supramolecular architecture through hydrogen bonding and CH…π_(ph) interactions.The prepared nanohybrid(Gd-CMP/TG) reveals significantly enhanced visible-light-induced photocatalytic activity for degradation of acetaminophen(ACT).The complete removal of 10 mg/L ACT is achieved over Gd-CMP/TG,and the corresponding rate constant of ACT degradation of nanohybrid is 40-fold higher than that of bare TiO_(2).In prepared ternary nanohybrid,metal-coordination sensitizer(Gd-CMP) acts as an electron donor,and at the same time,rGO serves as an electron acceptor,and the synergistic effect between them efficiently enhances charges separation and inhibits e/h pair recombination in the hybridized species.The radical scavenger tests indicate that the photo-induced O_(2)^(-·) radicals dominate ACT degradation.On the basis of the experimental results and calculated energy of electronic levels,a possible mechanism for the improved photocatalytic activity is discussed.