Selective detection of methanol vapour from a multicomponent gas mixture using a CNPs/ZnO@ZIF-8 based room temperature solid-state sensor

Abstract

Methanol vapour is harmful to human health if it is inhaled, swallowed, or absorbed through the skin.

A humidity-resistant and room temperature carbon soot@ZIF-67 composite sensor for acetone vapour detection

“…The D band represents defects within the graphene sheets that make up the CNPs, and the G band is due to the graphitic nature of the carbon nanoparticles. 18 Raman spectroscopy is often deployed to study carbon nanomaterials, typically by calculating the integrated intensity ratio between the D and G bands ( I D / I G ). Perumbilavil et al showed that the I D / I G ratio increases from graphite (0.70) to graphene oxide (1.03), due to the oxygen species present in the graphene oxide, and reduced graphene oxide had an I D / I G ratio of 0.93 indicating that there was a removal of oxygen species from graphene oxide.…”

“…The following formula ( eqn (1) ) was used to calculate the vapour concentration of the VOCs: where C is the vapour concentration (ppm), p is the density of the liquid analyte (g cm −1 ), T is the temperature (K), V s is the volume injected into the 20 L volumetric flask (μL), M r is the molar mass of the liquid analyte and V is the volume of the volumetric flask (L). 18 …”

“…The following formula (eqn (1)) was used to calculate the vapour concentration of the VOCs: where C is the vapour concentration (ppm), p is the density of the liquid analyte (g cm −1 ), T is the temperature (K), V s is the volume injected into the 20 L volumetric ask (mL), M r is the molar mass of the liquid analyte and V is the volume of the volumetric ask (L). 18 2.2.5 Sensor's response and recovery tests. The gas sensor's response time was dened as the time needed for the sensor to reach a 90% maximum response before it reaches the saturated (plateau) state, while recovery time was dened as the 90% time needed for the sensor to reach its baseline during the removal of the gas exposed from its plateau.…”

“…7d) and the correlation coefficient (R 2 ) and slope of the linear t were 0.99 and 0.062 U ppm −1 respectively. The LOD was approximated to be 484 ppb and was calculated using the formula LOD = 3 × RMS/slope, 18,50 where RMS was the standard deviation and the RMS was found to be 0.001.…”

Zeolitic imidazolate framework as humidity-resistant solid state-chemiresistive gas sensors: A review

“…ZnO@ZIF-8 sensors did not respond to any of the VOCs (methanol, ethanol, 2-propanol, acetone, chloroform, and ethyl acetate) tested at room temperature, but the pure CNPs sensor responded to VOCs showing little change in responses as the vapour concentration increases (see Fig. 15 ) [ 81 ]. In addition, CNPs/ZnO@ZIF-8 composite showed a 125 times improvement in methanol vapour response compared to the CNPs sensor.…”