Ultra-thin nanosheets-assembled hollowed-out hierarchical α-Fe2O3 nanorods: Synthesis via an interface reaction route and its superior gas sensing properties

Toward Tunable Photonic Nanosheet Sensors: Strong Influence of the Interlayer Cation on the Sensing Characteristics

“…For TBA x H 1− x TaP 2 O 8 films exposed to a short pulse of ethanol vapor, we observe a large optical shift of 1429 nm within only 322 ms (Figure a, Figure S14, Supporting Information). To our knowledge, this is the largest optical shift toward ethanol vapor and among the fastest response and recovery times (276 and 219 ms, respectively, see Figure S15a in the Supporting Information) to ethanol vapor reported to date (for a typical measurement see Video S1 and Figure S16 in the Supporting Information) . We primarily attribute the fast response time to the large surface area of the unilamellar nanosheets, augmented by their small size, their turbostratic disorder, and the fact that TBA + widens the interlayer space, all of which create a large number of grain boundaries acting as conduits for the diffusion of small molecules.…”

Thin 2D: The New Dimensionality in Gas Sensing

“…By using the same preparation procedure [74], they also prepared hollowed-out hierarchical α-Fe2O3 nanorods. A transient response to different concentrations of acetone is reported in Figure 14.…”

“…Huang and coworkers prepared hierarchical nanorods assembled by interlaced ultrathin nanosheets (with a thickness of around 3 nm), that possessed a large specific surface area and a novel open-style pore structure, which endowed it with large amount of gas adsorption and rapid gas diffusion [73,74]. Hollow and hollowed-out Co 3 O 4 microspheres were assembled by porous ultrathin nanosheets with a thickness of about 3 nm that were synthesized via a new rapid and energy-efficient room temperature interfacial-reaction.…”

State-of-the-Art Research on Chemiresistive Gas Sensors in Korea: Emphasis on the Achievements of the Research Labs of Professors Hyoun Woo Kim and Sang Sub Kim

“…To date, a variety of gas sensors have been utilized to detect toxic and hazardous gases. Among these, metal–oxide semiconductor (MOS) gas sensors, whose operation is based on the change in the resistance upon exposure to target gases, have attracted significant attention owing to their low cost, low toxicity, simple fabrication route, robustness, high stability, fast response/recovery times, and sensitivity to detect a wide range of target gases [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 ]. Notably, in addition to MOS, materials based on conducting polymers and graphene have been employed for the realization of resistive-gas sensors [ 18 ].…”

“…Thus, various synthesis approaches or strategies have been used to overcome the limitations of this type of gas sensors: namely, poor selectivity and high operating temperature. A comparison of the most commonly used pristine metal oxides, with different surface morphologies, as a sensing layer in chemiresistive-type of gas sensors is presented in Table 2 [ 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 ].…”