Gas sensor
The present invention refers to a gas sensor comprising a hybrid material of perovskite and graphene, to the method for obtaining said sensor and to the gas detection method using said sensor.
1 . Gas sensor comprising:
a hybrid material comprising formula ABX 3 metal halide perovskite nanocrystals, and graphene deposited on a substrate with electrodes where the perovskite nanocrystals are embedded in the graphene.
2 . Gas sensor according to claim 1 , where the graphene has less than 10% of oxygen functional groups.
3 . Gas sensor according to claim 1 , where A in the formula ABX 3 is a cation selected from: methylammonium, formamidinium and cesium.
4 . Sensor according to claim 1 , where the perovskite nanocrystals are comprised between 6 and 8 nanometers in size.
5 . Sensor according to claim 1 , the substrate of which is made of alumina.
6 . Sensor according to claim 1 , where A in the formula ABX 3 is methylammonium and X is bromine.
7 . Sensor according to claim 1 , where the gas to be detected is benzene and toluene, and A in the formula ABX 3 is methylammonium.
8 . Sensor according to claim 1 , where the gas to be detected is NO 2 , and A in the formula ABX 3 is formamidinium.
9 . Sensor according to claim 1 where the gas to be detected is NH 3 , A in the formula ABX 3 of the perovskite is methylammonium and X is a chlorine anion.
10 . Gas sensor according to claim 1 , where the halide of the perovskite is selected from chlorine and/or bromine and/or iodine.
11 . Method for obtaining a sensor defined according to claim 1 comprising the following steps:
a) preparing a graphene dispersion;
b) exfoliating the graphene from the previous dispersion;
c) adding and mixing the perovskite nanocrystals to the exfoliated graphene solution to obtain a hybrid material of graphene and perovskite;
d) depositing the hybrid material of graphene and perovskite on a substrate containing electrodes.
12 . Method according to claim 11 , where the solvent of the solution in step a) is toluene or hexane and the graphene consists of sheets of graphene.
13 . Method according to claim 11 , the graphene is exfoliated in step b) by pulsed sonication.
14 . Method according to claim 11 , where in step d) the substrate is alumina containing screen-printed platinum interdigitated electrodes.
15 . Gas detection method comprising the stages of:
a) placing the sensor defined in claim 1 in a chamber through which the gas flow passes,
b) measuring the variation of the resistance after the passage of gas.
16 . Method according to claim 15 , characterized in that stage b) is carried out at room temperature.