Nickelocene as precursor of microporous organometallic-derived carbon and nickel oxide-carbon nanocomposite

Ultra-Low-Density Carbon Nanotube Aerogel Film for Fast and Sensitive Bolometric Sensing

In various applications, infrared (IR) detectors with quick responses and high sensitivity at room temperature are essential. This work synthesizes carbon nanotube aerogel films (CAFs) with an ultra-low density of 1.33 mg cm^-3. Transient electrothermal (TET) technology is used to characterize the thermal and electrical transport of CAFs in the temperature range of 320 to 10 K. CAF has record-low thermal conductivity (2.5 mW m^-1 K^-1 at 320 K) and thermal diffusivity (2.24 × 10^-6 m² s^-1 at 320 K) in vacuum. The TCR of CAF is -0.11%/K at 295 K, which is 57% higher than that of the MWCNT films. In addition, the comprehensive bolometric performance of carbon nanotube aerogels is tested and analyzed, including the photothermal response, resistivity responsivity, and response time to lasers of a broad spectrum from ultraviolet to near-infrared. The relative responsivity of CAF to lasers of different wavelengths is found to be consistent. The response time of CAF with 200 μm suspended length is measured to be as short as 2.95-3.03 ms (framing rate of 330-339 per second). In addition, the resistive response of the CAF sample to a blackbody radiator and the radiation of the human hand also shows good sensitivity and repeatability. These results demonstrate the promising application of CAF as a sensitive and fast-response uncooled bolometer.

Organometallic-Derived Carbon (ODC)-Metal Nano-Oxide Composites as Improved Electrode Materials for Supercapacitors

In the search for the new generation of electrochemical energy storage materials, a novel and straightforward synthetic route for porous carbons and metal oxide nanoparticle composites based on the chlorination of the organometallic compounds Ni(C₅H₅)₂ and Mn(C₅H₇O₂)₂ at moderate temperatures, followed by hydrothermal treatment, has been developed. Electrochemical measurements in a three-electrode configuration show that, in both composites NiO@ODC and Mn₃O₄@ODC, a synergistic effect between the capacitive and pseudocapacitive energy storage mechanisms is observed, thereby improving their electrochemical performance vs pure carbon materials. Electrochemical evaluation of symmetric cells gave gravimetric capacitances of 124 and 130 F g^-1 for NiO@ODC and Mn₃O₄@ODC, respectively. However, the porous structure of the carbon matrix and the higher conductivity of Mn₃O₄, together, were found to be responsible for the superior electrochemical performance of Mn₃O₄@ODC.