Coal tar pitch derived nitrogen-doped carbon dots with adjustable particle size for photocatalytic hydrogen generation

Carbon dots (CDs) with tunable size were synthesized form coal tar pitch through a simple hydrothermal method using NaOH as additive. The chemical composition and morphological feature of the obtained CDs were characterized. The prepared CDs were high crystallinity in nature. The size of CDs could be regulated by varying the addition amount of NaOH. By increasing the CDs’ size from 1.9 to 5.8 nm, the CDs supported Pt show a 70% improvement in the solar-to-hydrogen efficiency.