Low-Operating-Temperature NO2 Sensor Based on a CeO2/ZnO Heterojunction

Abstract

CeO2/ZnO-heterojunction-nanorod-array-based chemiresistive sensors were studied for their low-operating-temperature and gas-detecting characteristics. Arrays of CeO2/ZnO heterojunction nanorods were synthesized using anodic electrodeposition coating followed by hydrothermal treatment. The sensor based on this CeO2/ZnO heterojunction demonstrated a much higher sensitivity to NO2 at a low operating temperature (120 °C) than the pure-ZnO-based sensor. Moreover, even at room temperature (RT, 25 °C) the CeO2/ZnO-heterojunction-based sensor responds linearly and rapidly to NO2. This sensor’s reaction to interfering gases was substantially less than that of NO2, suggesting exceptional selectivity. Experimental results revealed that the enhanced gas-sensing performance at the low operating temperature of the CeO2/ZnO heterojunction due to the built-in field formed after the construction of heterojunctions provides additional carriers for ZnO. Thanks to more carriers in the ZnO conduction band, more oxygen and target gases can be adsorbed. This explains the enhanced gas sensitivity of the CeO2/ZnO heterojunction at low operating temperatures.

Influence of Nickel Doping on Ultrahigh Toluene Sensing Performance of Core-Shell ZnO Microsphere Gas Sensor

“…Figure 3c is the HRTEM images of the 1 at% Ni-ZnO sample. The lattice spacings were 0.286 and 0.249 nm, corresponding to the (100) and (101) crystal planes of ZnO [46,47]. Interplanar spacing corresponding to NiO was not found, which is consistent with the results of the XRD.…”

Study of the mechanism pathway of sulfasalazine degradation on a novel quadripartite visible-light-driven photocatalyst

“…The major problem efficiency in the heterogeneous photodegradation is the e/h recombination, and thus, when it is relatively high the overall efficiency of the process can be drastically low (AlSalhi, Sakthisabarimoorthi, Devanesan, Martin Britto Dhas, & Jose, 2019). This drawback can be overcame critically by various techniques including converting the semiconductor to nanoscale (Ahmad et al, 2021;da Silva, Druzian, Oviedo, Muraro, & Oviedo, 2021), supporting on various supports (Nguyen Phuoc, Le, Pham, & Le, 2021;Rahman, El-Kamash, & Hung, 2022;Tehubijuluw, Subagyo, Kusumawati, & Prasetyoko, 2022), coupling of two or more semiconducting materials or construction of heterojunction systems or co-catalysts (Adenuga, Skosana, Tichapondwa, & Chirwa, 2021;AttariKhasraghi, Zare, Mehrizad, Modirshahla, & Behnajady, 2021;Gulino et al, 2021;Piriyanon et al, 2021;Sun, Zhan, Chen, & Lin, 2021), doped systems with metals/non-metals species (Alamro, Mostafa, Abu Al-Ola, Ahmed, & Toghan, 2021;Manda et al, 2022), etc. Thus, coupling of nano scale semiconductors was used to enhance the photocatalytic activity of Cu 2 O, CdS, BiVO 4 , and WO 3 in this work.…”