Studies on structural, spectral and morphological properties of co-precipitation derived Co-doped ZnO nanocapsules for NO2 sensing applications

Impact of oxygen vacancies on enhanced NO2 gas sensing performance of lithium doped Co:ZnO thin films

“…Therefore, it is evident that only adsorbed oxygen ions contribute to the decline in gas sensitivity. According to V S Kamble et al Co-doped ZnO synthesized by the co-precipitate method showed a 286% NO 2 gas sensing response at 200 °C [9]. In our study, Co-Li co-doped ZnO thin films showed a NO 2 gas sensing response of 2940.17% achieved at 210 °C.…”

“…Our results demonstrate that the acceptor property of Co 2+ in ZnO Sample CL-2 causes conductivity switches from n-type to p-type that leads to a reduction in carrier density, table 2. The divalent Co 2+ ion traps free electrons from the donor levels, which lowers n-type donor carrier concentrations and increases resistance [9]. Even a small amount of cobalt within the solubility limit decreases the carrier concentration by enhancing the ZnO resistivity [35].…”

“…Recently, the efficiency of gas-sensing properties of ZnO has been improved by doping it with transition elements [3][4][5][6][7][8]. Among the transition metals, Cobalt (Co) doped ZnO exhibits superior electron transport, tailored band structure, and increased surface reactivity that will enhance NO 2 gas sensing capabilities [9,10]. A number of research groups have claimed that using alkali metals to modify the physical and chemical properties of ZnO can improve the detection of gas [2,[11][12][13].…”

Highly electroactive Co–ZnO/GO nanocomposite: Electrochemical sensing platform for oxytetracycline determination

“…cm −1 and 1638 cm −1 , corresponding to the O–H stretching and H– O –H bending vibrations, respectively. These peaks indicate the presence of small amounts of H₂O content, probably as moisture, on the surface of the Co–ZnO nanocrystals [ 27 , 28 ].…”

Highly Efficient NO2 Sensors Based on Al-ZnOHF under UV Assistance

“…Hence, the introduction of a low content of Al 3+ can significantly narrow the bandgap of ZnOHF, and the 0.5 at.% Al-ZnOHF sample has the minimum bandgap. The UV absorption and bandgap are the main influencing factors of the generation of photoactivated electrons and holes, thereby affecting the gas-sensing process [37,53]. Therefore, compared with other samples, 0.5 at.% Al-ZnOHF exhibits the highest increase in the response value rate before and after UV light radiation.…”