Tin monosulfide (SnS) nanosheets were synthesized through a one-pot process and were characterized. Crystal structure was determined as orthorhombic herzenbergite. SnS nanosheets were determined to be several micrometers in width and a few tens of nanometers in thickness. Relationship between SnS nanosheet geometry and crystal orientation was determined by transmission electron microscopy (TEM) observation. The bottom faces of SnS nanosheets were observed to correspond to the a x c-plane. At the side faces, the (101) plane was mainly exposed. From photoelectrochemical measurements, the valence band and conduction band positions were estimated to be 0 and -1.3 V vs the saturated calomel electrode (SCE), respectively. (C) 2014 The Japan Society of Applied Physics