Sensitive and selective n-butanol gas detection based on ZnO nanocrystalline synthesized by a low-temperature solvothermal method

Highlights: • ZnO nanocrystalline were synthesized by a low-temperature solvothermal method. • ZnO nanocrystalline were employed as gas sensor for the detection of n-butanol gas. • ZnO nanocrystalline exhibits a fast response time, high response and excellent selectivity. • ZnO nanocrystalline would be promising as the sensing materials in n-butanol detection. ZnO nanocrystalline with a few nanometers in size were synthesized by a low-temperature solvothermal method from zinc acetate dihydrate (Zn(CH₃COO)₂·2H₂O), potassium hydroxide (KOH) and ethanol (C₂H₅OH). X ray diffraction (XRD), transmission electron microscopy (TEM) and X ray photoelectron spectroscopy (XPS) were used to characterize the structure, morphology, specific surface area and chemical state of the samples. The analyzed results indicate that the ZnO nanocrystalline with good dispersion are several nanometers in size about 10 nm. The ZnO nanocrystalline was used as sensing material to fabricate an indirect-heating structure sensor and its gas sensing properties are tested. At the optimal operating temperature (340 °C), its gas response toward 500 ppm n-butanol is 148.11 and the response and recovery time are 20 and 8 s, respectively. The test results show that the sensitivity of the as-prepared gas sensor has high selectivity to n-butanol and good response/recovery characteristics, linear response, short-term repeatability, as well as the long-term stability. The experimental results show that the gas sensor based on ZnO nanocrystalline can be used in the detection and real-time monitoring of toxic gases, especially n-butanol gas, which makes it to be highly promising candidate for practical detectors for n-butanol gas.