Synthesis of high-quality ultrathin titanium carbide nanosheets and films through immiscibility approach

•High-quality TiCx nanosheets and films were synthesized by a novel method.•A facile immiscibility approach was developed based on chemical vapor deposition.•Effect of the temperature, time and methane concentration are investigated.•Hexagonal TiCx nanosheets have a uniform size (∼600 nm) and thickness (∼4 nm).