Shanghai University

About: Shanghai University is a education organization based out in Shanghai, Shanghai, China. It is known for research contribution in the topics: Microstructure & Catalysis. The organization has 59583 authors who have published 56840 publications receiving 753549 citations. The organization is also known as: Shànghǎi Dàxué.

A low temperature formaldehyde gas sensor based on hierarchical SnO/SnO2 nano-flowers assembled from ultrathin nanosheets: Synthesis, sensing performance and mechanism

Abstract: Here we report a hierarchical flower-like SnO/SnO2 gas sensing material for detecting formaldehyde vapor at a low temperature. It was rationally designed and successfully synthesized via a one-step hydrothermal route. The crystal phase, defects, element composition and morphology of the obtained samples were characterized in detail by XRD, FESEM, TEM, Raman, PL, and XPS. The characterized results reveal that hierarchical SnO/SnO2 nano-flowers are assembled from ultrathin nanosheets with about 9–11 nm in thickness. Gas sensing performance shows that the sensor based on SnO/SnO2 nano-flowers has crucial advantages for formaldehyde detection, such as low operating temperature (120 °C), excellent selectivity, short response time (7 s), high response value (80.9) and low detection limitation (8.15 ppb). The excellent gas responses of the sensor can be attributed to its unique hierarchical microstructure (for decrease of Rg and increase of Ra) and p-n junction between SnO and SnO2 (for increase of Ra). Finally, the sensing mechanism of the prepared was proposed in detail.

A flexible pressure sensor based on an MXene–textile network structure

Abstract: High-performance pressure sensors have attracted considerable attention recently due to their promising applications in touch displays, wearable electronics, human–machine interfaces, and real-time physiological signal perception. However, the “functionality” of a sensor is generally incompatible with “simple” fabrication strategies. Therefore, strategies that are less equipment-intensive and less expensive are required for enhancing the sensor performance. Here, we propose a flexible piezoresistive pressure sensor based on MXene–textile prepared by a facile dip-coating process. Benefiting from the excellent electrical properties of MXene and the abundant wavy surface of cotton textile, this pressure sensor exhibits high sensitivity (12.095 kPa−1 for the range 29–40 kPa and 3.844 kPa−1 for the range less than 29 kPa) with a rapid response time of 26 ms, and excellent cycling stability (5600 cycles). The real-time monitoring of human physiological signals such as wrist pulse, voice detection, and finger movements can be achieved by using this MXene–textile sensor. In addition, sensory arrays were successfully applied in the pressure distribution mapping of a key, demonstrating that the pressure sensor can be used as part of wearable devices and human–machine interfaces to sense pressure.