Double quantum dots decorated 3D graphene flowers for highly efficient photoelectrocatalytic hydrogen production

•We synthesised the TiO2 and Au dual quantum dots (QDs) on three-dimensional graphene flowers (Au@TiO2@3DGFs) for PEC hydrogen production.•The 3DGFs as a scaffold for dual QDs can provide more active sites and more stable structure.•The newly-developed Au@TiO2@3DGFs composite exhibited a surprisingly PEC activity and excellent durability.