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Gas sensing is a powerful tool for detecting the leakage of some hazardous gases and monitoring human health. However, most of the sensors based on metal oxide semiconductors can only function at elevated operating temperatures, which leads to high power consumption and poor durability. Here, Au nanoparticle decorated In2O3 nanofibers (IO-Au NFs) have been successfully synthesized by one-step coaxial electrospinning for efficient sensing of ethanol gas at low temperature. The temperature and gas concentration effects on the sensing properties of the IO-Au NFs confirm that the Au decoration can remarkably improve the response, reduce the detection limit down to 1 ppm, and lower the sensors’ optimal operating temperature down to 175 °C. The IO-Au-0.42 sensor with the optimized Au concentration presents a superior response of 116.13 to 100 ppm ethanol at 175 °C, which is six times larger than that of the pristine In2O3 sensor. Moreover, the IO-Au-0.42 sensor exhibits a much shorter response/recovery time of 2 s/152 s to 100 ppm ethanol gas at 175 °C than the pristine In2O3. Surprisingly, even at room temperature, the IO-Au-0.42 sensor still presents a high response of 11.12 to 100 ppm ethanol, which is 5.4 times larger than that of the pristine In2O3 sensor, and shows a short response/recovery time of 47 s/351 s. This enhanced sensing performance at low temperature can be mainly ascribed to the synergistic action of the catalytic effect, spillover effect, electronic sensitization effect, and deficient oxygen concentration. [ABSTRACT FROM AUTHOR]

Carbon quantum dots/TiO2 nanotubes composites were prepared by a simple technical route through which TiO2 nanotubes prepared by electrospinning were dispersed in carbon quantum dots solution, and dried at 80 °C. The results indicated that the TiO2 nanotubes composites were combined with the carbon quantum dots. The photocatalytic activity of the carbon quantum dots/TiO2 nanotubes composites was investigated by the degradation of rhodamine B under visible light irradiation, and it was demonstrated to be significantly enhanced compared with that of pure TiO2 nanotubes. Through analysis, this enhancement of visible light photocatalytic activity was attributed to the carbon quantum dots with the unique up-converted photoluminescence behavior. [ABSTRACT FROM AUTHOR]

Highly photoluminescent ZnSe/Au nanocomposites have been prepared via a simple low-temperature-aqueous synthesis and direct coupling approach. The mechanism of surface plasmons enhanced photoluminescence of ZnSe/Au nanocomposites is investigated. Furthermore, due to high photostability and biocompatibility, the as-prepared ZnSe/Au nanocomposites are demonstrated as excellent probes in cellular imaging. [ABSTRACT FROM AUTHOR]

We have successfully prepared iron oxide and nickel oxide on carbon nanotubes on carbon cloth for the use in supercapacitors via a simple aqueous reduction method. The obtained carbon cloth-carbon nanotube@metal oxide (CC-CNT@MO) three-dimensional structures combine the high specific capacitance and rich redox sites of metal oxides with the large specific area and high electrical conductivity of carbon nanotubes. The prepared CC-CNT@Fe 2 O 3 anode reaches a high capacity of 226 mAh·g -1 at 2 A·g -1 with a capacitance retention of 40% at 40 A·g -1 . The obtained CC-CNT@NiO cathode exhibits a high capacity of 527 mAh·g -1 at 2 A·g -1 and an excellent rate capability with a capacitance retention of 78% even at 40 A·g -1 . The all-solid-state asymmetric supercapacitor fabricated with these two electrodes delivers a high energy density of 63.3 Wh·kg -1 at 1.6 kW·kg -1 and retains 83% of its initial capacitance after 5000 cycles. These results demonstrate that our simple aqueous reduction method to combine CNT and metal oxides reveals an exciting future in constructing high-performance supercapacitors., (Copyright © 2019, Zhang et al.; licensee Beilstein-Institut.)