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.