A Non-Van der Waals two dimensional material from microwave synthesized Cu₂ZnSnS₄ nanocrystal agglomerates

Copper Zinc Tin Sulphide (Cu2ZnSnS4 (CZTS)) is an attractive and promising semiconductor material due to its photovoltaic and catalytic properties and earth abundant non-toxic elemental constituents. Confining it to two dimensions and enlarging its surface area enriches its catalytic activity. Here, we demonstrate the liquid phase exfoliation of CZTS to two dimensional (2D) CZTS sheets having few nm thickness and size of ∼200 nm. The starting material for exfoliation was prepared by rapid microwave assisted synthesis of CZTS nano crystal agglomerates. The disc shape and increased band gap of 2D CZTS help in forming a hetero junction with titania nano tubes with enhanced light harvesting capability and ability to create and separate charge carriers required for photo catalytic water splitting.