Graphene triggered hole activation strategy for 2D/2D-Layered (0 0 1)/(1 0 0)WO3 facet junction towards enhanced photocatalytic water oxidation kinetics

Single layer graphene hybridized 2D ternary GR/(001)/(100)WO 3 heterojunction synthesized through a simple two step hydrothermal method showed highly efficient photocatalytic oxygen evolution performance mainly owing to the synergistic promoting effects of the improved separation and prolonged lifetime of photocharges, the reduced energy barrier for O-O formation, and the lower overpotential of water oxidation reaction comparable to most active RuO 2 . • GR hybridized GR/(001)/(100)WO 3 possesses an AQE of 26.7% at 420 nm. • The -C-W- “bridge” acts as electron transfer channel for construction of internal electric field at GR-(001)WO 3 interface. • The apparent activation energy and overpotential of GR/(001)/(100)WO 3 are comparable to the most active RuO 2 . An unique graphene hybridized 2D ternary GR/(001)/(100)WO 3 facet junction is designed by combining the advantages of heterojunction and unique bi-functional graphene working as hole trap and co-catalyst in photocatalytic water splitting. By a facile two-step hydrothermal method, (001)WO 3 with highly exposed facet is connected to graphene through -C-W-“bridge”, while (100)WO 3 grows on the surface of (001)WO 3 affording efficient generation of photocharges. GR/(001)/(100)WO 3 is highly active in oxidation of water, with an apparent quantum efficiency of 26.7% at 420 nm. The -C-W- “bridge” acts as electron transfer channel for construction of internal electric field at GR/(001)WO 3 interface, which would direct photo-generated holes towards graphene for water oxidation. The charges dynamics analysis and theoretical simulations demonstrate that the superior photocatalytic activity mainly results from the synergistic promoting effects of the improved separation and prolonged lifetime of photocharges, the reduced energy barrier for O-O formation, and the lower overpotential of water oxidation reaction comparable to the most efficient RuO 2 . This work provides a promising pathway to develop graphene hybridizing structure with dual functions for boosting photocatalytic reactions.