Highly sensitive detection toward aniline vapor promoted by heterojunction between covalent organic frameworks and biocarbon

High-Performance Trimethylamine Sensor Based on an Imine Covalent Organic Framework

“…In order to minimize them into a response−time sensing curve, the gas response is calculated using the formula response = ΔI/I air = (I gas − I air )/I air , where I air and I gas are the currents in the air and target gas, respectively. 39 This work tested the gas sensing performance of the TA, BT, and TB-COF sensors at a temperature of 25 °C with a 4 V voltage setting. We analyzed the TA, BT, and TB-COF sensors for 500 ppm of TMA, ethylenediamine (EDA), 1 4a, Figure S3, and Figure S4, we can see that TA, BT, and TB-COF sensors have a good response mainly for TMA and EDA, which to some extent indicates that all three sensors have good selectivity.…”

“…The response time is the time required to reach 90% of the stabilized response value, while the recovery time is the time required to return to within 10% of the initial response value. 39 The response/ recovery times of the TA, BT, and TB-COF sensors for 15 target gases are shown in Figure 4c The TB-COF sensor is expected to be a TMA sensor because of its good selectivity to TMA. On this basis, we tested 12 response cycles of 500 ppm of TMA (Figure 5a), and the average response rate was 6915.61%.…”

“…To further test the LoD of the TB-COF sensor for TMA, different concentrations of TMA were also tested and fitted. The theoretically calculated LoD was defined as LoD = 3S D /m, 39 where m is the slope of the linear part of the calibration curve and S D is the standard deviation of noise in the response curve. As can be seen in Figure 5c, the response of the TB-COF sensor to TMA gradually increased with an increasing gas concentration (50−500 ppm).…”

“…The current–time sensing curves for TA, BT, and TB-COF are shown in Figure S2. In order to minimize them into a response–time sensing curve, the gas response is calculated using the formula response = Δ I / I air = ( I gas – I air )/ I air , where I air and I gas are the currents in the air and target gas, respectively . This work tested the gas sensing performance of the TA, BT, and TB-COF sensors at a temperature of 25 °C with a 4 V voltage setting.…”

“…The response/recovery time is also an important index to evaluate the good sensitivity of the sensor. The response time is the time required to reach 90% of the stabilized response value, while the recovery time is the time required to return to within 10% of the initial response value . The response/recovery times of the TA, BT, and TB-COF sensors for 15 target gases are shown in Figure c and Figure S5a.…”