Graphene Bridge for Photocatalytic Hydrogen Evolution with Gold Nanocluster Co-Catalysts

Herein, the UV light photocatalytic activity of an Au(101)NC-AlSrTiO(3)-rGO nanocomposite comprising 1 wt% rGO, 0.05 wt% Au(101)(PPh(3))(21)Cl(5) (Au(101)NC), and AlSrTiO(3) evaluated for H(2) production. The synthesis of Au(101)NC-AlSrTiO(3)-rGO nanocomposite followed two distinct routes: (1) Au(101)NC was first mixed with AlSrTiO(3) followed by the addition of rGO (Au(101)NC-AlSrTiO(3):rGO) and (2) Au(101)NC was first mixed with rGO followed by the addition of AlSrTiO(3) (Au(101)NC-rGO:AlSrTiO(3)). Both prepared samples were annealed in air at 210 °C for 15 min. Inductively coupled plasma mass spectrometry and high-resolution scanning transmission electron microscopy showed that the Au(101)NC adhered almost exclusively to the rGO in the nanocomposite and maintained a size less than 2 nm. Under UV light irradiation, the Au(101)NC-AlSrTiO(3):rGO nanocomposite produced H(2) at a rate 12 times greater than Au(101)NC-AlSrTiO(3) and 64 times greater than AlSrTiO(3). The enhanced photocatalytic activity is attributed to the small particle size and high loading of Au(101)NC, which is achieved by non-covalent binding to rGO. These results show that significant improvements can be made to AlSrTiO(3)-based photocatalysts that use cluster co-catalysts by the addition of rGO as an electron mediator to achieve high cluster loading and limited agglomeration of the clusters.