▎ 摘　　要

NOVELTY - Detecting ammonia by using worm-like mesoporous polypyrrole-reducing graphene oxide nano-sheet as sensor involves dispersing the worm-like mesoporous polypyrrole-reduced graphene oxide in a solvent, make it uniformly dispersed by ultrasound, and applying the uniformly dispersed suspension to the outer wall of the ceramic tube to form a uniform cylindrical film. The length of the ceramic tube is 0.5-1 cm, and the diameter is 0.1-0.3 cm. The two ends of the ceramic tube are 0.1-0.3 cm away from the edge with gold electrodes and wires connected to the electrodes, and after drying, the sensor is obtained. The two wires of the prepared sensor are connected to a resistance measuring instrument (such as a multimeter), and fixed the sensor in a closed cavity. A micro syringe is used to take ammonia water with a volume and different mass fractions, and injected into or above the electric heating block of the cavity through the small hole on the top of the closed cavity. USE - The method is useful for detecting ammonia by worm-like mesoporous polypyrrole-reducing graphene oxide nano-sheet. ADVANTAGE - The method enables detecting ammonia with good shape, regular mesoporous structure, large specific surface area, improved detection sensitivity of ammonia at room temperature, high sensitivity and good selectivity, in simple manner. DETAILED DESCRIPTION - Detecting ammonia by using worm-like mesoporous polypyrrole-reducing graphene oxide nano-sheet as sensor involves dispersing the worm-like mesoporous polypyrrole-reduced graphene oxide in a solvent, make it uniformly dispersed by ultrasound, and applying the uniformly dispersed suspension to the outer wall of the ceramic tube to form a uniform cylindrical film. The length of the ceramic tube is 0.5-1 cm, and the diameter is 0.1-0.3 cm. The two ends of the ceramic tube are 0.1-0.3 cm away from the edge with gold electrodes and wires connected to the electrodes, and after drying, the sensor is obtained. The two wires of the prepared sensor are connected to a resistance measuring instrument (such as a multimeter), and fixed the sensor in a closed cavity. A micro syringe is used to take ammonia water with a volume and different mass fractions, and injected into or above the electric heating block of the cavity through the small hole on the top of the closed cavity, and turn on the heating power supply external to the electric heating block. The heating makes the ammonia water in the cavity fully volatilize, and the final ammonia concentration in the cavity is determined according to the volume of the cavity, the concentration of ammonia water and the amount added, and turned off the external heating power supply. The stopwatch is started and recorded the resistance change value delta R in the length direction of the ceramic tube within the specified response time T (the difference between the resistance value after the reaction with ammonia and the resistance value before the reaction). The reaction is over, then opened the chamber cover to allow fresh air to enter the chamber, and the resistance begins to recover, and recorded the resistance recovery value within the specified recovery time, and repeat this measurement process, the measurement process is carried out more than 5 times in total. The collected resistance data is exported through a resistance measuring instrument program (such as a multimeter program) to get the change value of the resistance signal over time, with the concentration of ammonia as the abscissa, and taken the change value delta R of the resistance signal compared to the initial value Ro ( delta R/Ro) as the ordinate to plot, and select at least 5 points to obtain the standard curve. The volume of ammonia water is taken with unknown concentration, and performed measurement measurement operation method, and substituted the measured resistance signal change value into the standard curve to calculate the ammonia concentration.