TiS2 with reduced particle sizes (labelled nano-TiS2) is prepared via ball-milling in a zirconia jar with a milling time of 8 h at 600 rpm. 9 large and 10 small zirconia balls are employed with a diameter of 10 mm and 0.1 mm, respectively, with a mass ratio of 31.5 g balls to 1 g sample.