Influence Of Oxygen-containing Groups Research Articles

Study on the influence of oxygen-containing groups on the performance of Ni/AC catalysts in methanol vapor-phase carbonylation

The activated carbon was pretreated by different concentrations of HNO3 solution to prepare Ni/AC catalysts with different oxygen contents. The change of the oxygen-containing groups during the carbonylation was traced using an instrument named Micro-Fluidized Bed Reactor Analyst-Particle (MFBRA-P), which can sample out catalyst particles on-line at specific time interval during the reaction. The on-line sampled catalysts were characterized by N2-sorption, inductively coupled plasma-atomic emission spectroscopy (ICP-AES), transmission electron microscope (TEM), temperature programmed desorption (TPD), Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). It was found that catalysts with smaller amount of oxygen-containing groups had higher initial activity and higher deactivation rate, which was consistent with the accumulation rate of oxygen-containing groups. High content of oxygen suppressed the accumulation of oxygen-containing carbonaceous deposits, resulting in better catalytic stability for carbonylation.

Influence of oxygen-containing groups on the photocatalytic properties of ZnO/graphene oxide composite

Graphene oxide nanosheets synthesized by using the chemical exfoliation method were hybridized with ZnO nanoparticles to fabricate ZnO/graphene oxide (GO) composite. A series of ZnO/GO composite with different C/O ratios were then obtained through gradual UV light reduction process. Roles of these oxygen-containing groups in the GO-based ZnO/GO composite photocatalyst were investigated through degradation of Rhodamine B. The underlining mechanism was discussed at the end based on the characterization results.

Ultrastrong Single-Walled Carbon Nanotubes/Graphene Oxide Nanosheets Hybrid Network Films as Flexible Electrode for Energy Storage

Homogeneous free-standing SWCNT/GO hybrid network films were fabricated using vacuum filtration method and their performances to be used as flexible electrodes in electrochemical capacitors were studied. Firstly, the SWCNT/GO hybrid films were treated under different temperature to investigate the influence of oxygen-containing groups on GO nanosheets on capacitive performance of them. Our results showed that the content of oxygen-containing groups had great influence on the capacitive performance of SWCNT/GO hybrid films and that the film annealed at 250 degrees C under 5% H2/Ar flow displayed an optimal capacitive performance. For the film with SWCNT/GO mass ratio of 1:4, specific capacitances of 171.85, 162.9, 148.98, 133.8, 112.8 and 82.24 F/g corresponding to discharge current of 5, 10, 20, 40, 80 and 160 A/g, respectively, were achieved. Secondly, the influence of mass ratio of SWCNT/GO on capacitive performance of SWCNT/GO hybrid films was also demonstrated. The hybrid films exhibited extremely high mechanical strength with tensile strength up to 461 MPa and specific capacitance of 105.2 F/g at current density of 5 A/g in case of 1:1 mass ratio of SWCNT/GO. A higher specific capacitance of 206.7 F/s at discharge current of 5A/g was obtained for the films with SWCNT/GO mass ratio of 1:8. Our SWCNT/GO hybrid network films showed good flexibility and durability over 2000 bending cycles test, indicating the potential to be used in flexible energy-storage devices.