“…Semiconductor gas sensors, with advent of simplicity, high sensitivity and fast response, offer the potential for developing portable and inexpensive gas-detection instrumentation. Semiconductor gas sensors including SnO 2 , ZnO, Fe 2 O 3 , etc., have been fabricated by various means and well-studied in the literature to detect most of the reducing gases [1][2][3][4][5][6][7][8][9][10][11][12]. Nanostructures of various metal oxides and also chalcogenides have been considered to increase the specific surface area exposed to gas [13][14][15].…”