SnO₂ Nanostructure as Pollutant Gas Sensors: Synthesis, Sensing Performances, and Mechanism

Table 1

Fabrication method of SnO₂-based materials.

Method	Material	Substance	Condition	Reference
Hydrothermal	SnO2	SnCl2·2H2O, NaOH, and CTAB	In autoclave at 130°C for 24 hours	[10]
		SnCl2·2H2O, urea, and citrate acid	Entered into microwave accelerated reaction system at temperature of 90, 120, and 160°C for 30 minutes and at 120°C for 10 and 60 minutes	[11]
		SnCl4·5H2O, NaOH, HMT, PEG, and H2C2O4	Entered into autoclave at 180°C for 24 hours	[12]
		SnCl2·H2O, Na3C6H5O7·2H2O, NaOH, and Zn(NO3)2·6H2O	Entered into autoclave at 180°C for 12 hours	[13]
		SnCl4·5H2O, NaOH	Entered into autoclave (temperature (°C) : time (hours), 190 : 48, 190 : 24, 160 : 20, and 100 : 20)	[14]
Chemical Precipitation	SnO2	SnCl2·5H2O, CO(NH2)2	Al2O3 tube is entered into solution for 6 hours at 95°C.	[15]
		SnCl4·5H2O, La(NO3)3, and NH3·H2O	Dropped NH3·H2O into solution till pH >8, washed with water and heated for 2 hours at 450°C	[16]
	Mn doped SnO2	SnCl2, Mn(CH3COO)2·4H2O, HCl, and NH4HCO3	Stirred at 60°C, droped HCl and NH4HCO3 into solution till pH 9 Dispersed with ultrasonic for 30 minutes and dried at 150°C. heated at 450–800°C for 3 hours	[17]
	ZnO-SnO2 nanocomposite	SnCl4·5H2O, ZnSO4·7H2O, and NaOH	Dropped NaOH into solution for different pH (3, 5, 7, 9, and 11). Dried at 100°C for 1 hour	[18]
Electrochemical	Nanohybrid foams SnO2/CuO	Sn/SnO2-coated substrate, sulfuric acid, lead sulfate, and copper sulfate	Electrodeposition is done with current density 0,667 A cm^−2 for 10 seconds and then heated at 700°C for 1 hour	[19]
	SnO2 nanotube	Polycarbonate membrane coated with gold, copper band, SnCl2, NaOH, and nitrate acid	= −0,4 V; after deposition, washed by dichloromethane and isopropanol; the last process, heated at 400°C for 4 hours	[20]
Electrochemical	SnO2 foams	SiO2/Si substrate, dibutyltin diacetate (DBTDA), sulfuric acid, and lead sulfate	Current density 2 A/cm^2, after deposition, heated at 700°C for 1 hour	[21]
Thermal oxidation	SnO2	SiO2 substrate, Sn, and oxygen	Deposited Sn on substrate by electron beam, heated Sn film with O2 atmosphere (flow speed, 200 mL/minutes) at 200°C for 2 hours, 400°C for 2 hours, and 600°C for 8 hours	[22]
		SnN, Si substrate	Deposited SnN on Si substrate by sputtering; heated film at 400–800°C for 2 hours	[23]