A theoretical study of 0D Ti₂CO₂/2D g-C₃N₄ Schottky-junction for photocatalytic hydrogen evolution

The construction of Schottky junctions is considered to be an efficient way to boost spatial charge separation and transfer in photocatalytic systems. In this work, we construct the Schottky junction using zero-dimensional (0D) Ti₂CO₂ nanoclusters (TCO) and two-dimensional (2D) g-C₃N₄ (GCN), denoted as TCO/GCN. The interfacial interaction, separation of photogenerated carriers, and reaction driving force of the TCO/GCN have been investigated based on density functional theory (DFT) calculations. TCO can serve as an electron acceptor due to the larger work function relative to the semiconductor GCN. The band bending caused by the interfacial charge prevents the electrons from flowing back to the semiconductor, which can effectively separate the photo-excited carriers. The metal sites exposed at the edge of TCO exhibit high hydrogen evolution reaction (HER) activity. This study provides a new idea for the development of 0D/2D Schottky junction photocatalysts.