MOF-derived CoOOH nanosheets and their temperature-dependent selectivity for NOx and ethanol

Specific surface area and oxygen vacancies are considered to be essential factors to enhance the gas sensitivity properties of sensing materials. Herein, we first synthesized Co/Zn-MOF and Co-MOF precursors, then formed 1CoOOH and 2-CoOOH nanosheets by etching the precursors with sodium hydroxide solution. The composition and morphology of 1-CoOOH and 2-CoOOH are characterized by XRD, FT-IR, SEM, and XPS. The results of gassensitive tests show that the responses of 1-CoOOH and 2-CoOOH are 14.28 and 3.87 for 100 ppm NOx at room temperature and 21.27 and 8.69 for 100 ppm ethanol at 150 degrees C, respectively. This indicates a better response of 1-CoOOH to 100 ppm NOx, and the materials are used to detect NOx and ethanol by controlling the working temperature. Compared with 2-CoOOH, the higher specific surface area and the abundance of oxygen vacancies of 1-CoOOH promote enhanced gas sensing properties.