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Abstract: Electrospun porous carbon nanofibers fabricated by electrospinning and steam activation were functionalized by spontaneous grafting of phenylsulfonic acid (PSA) groups. SEM and Raman observation suggested that modified electrospun nanofibers did not exhibit distinct changes of surface morphology and intrinsic graphitic structure. Nitrogen adsorption showed decrease in surface area and pore volume of modified carbon nanofibers. XPS and elementary analysis were conducted to characterize the surface chemistry of carbon nanofibers. The hydrophilic character was measured by the contact angles and static adsorption isotherms of water. The adsorption isotherms of benzene and butanone showed that the increasing hydrophilicity led to enhancement of adsorption performance for butanone on carbon nanofibers, indicating that the adsorption selectivity to hydrophilic organic compounds was improved. [Copyright &y& Elsevier]

It’s demonstrated that the defects induced by doping can greatly influence the sensing properties of oxide-based gas sensors. In this work, the authors have designed indium tin oxide nanotubes (ITO NTs) with different Sn doping concentrations. Results showed that the walls of ITO NTs are comprised of the formed ITO and redundant In 2 O 3 nanoparticles (NPs) at low doping concentration, and the doping-induced oxygen vacancies ( V o · · S ) can be tuned by Sn concentrations. Series of sensing tests to formaldehyde gas indicated that the ITO-7 NTs show the lowest working temperature (160 °C) and the highest specific response. Here, It is noted that to eliminate the influence of the coating amount of sensing performances, a concept of specific response was proposed i.e., R air /( m – R gas ), where R air and R gas respectively stand for the resistances of gas sensors in the reference gas (in air this case) and in the test gas ambience, and m stands for the mass of the coated sensing materials. The decreased working temperature could be attributed to the formed In 2 O 3 NPs/ITO tubular structure, and the enhanced specific response might be mainly associated with the V o · · S . Furthermore, a possible gas sensing enhancing mechanism via V o · · S for ITO-based gas sensors was proposed based on our results and analysis. This research would give some instructive advice to design high-performances oxide-based gas sensors via tuning the V o · · S . [ABSTRACT FROM AUTHOR]

The partially-embeddedMnO/ECNF composite electrodes exhibit an much lower decay rate (0.004‰ per cycle for 20,000 cycles) than those of the traditionnal MnO 2 /ECNF ones (decay rate of 0.015‰ per cycle for 8000 cycles). • The MnO nanocubes were partially inserted into the ECNF skeletons to make a strong joint between them. • The h-MnO/ECNF electrodes exhibit a super excellent cycling stability. • The h-MnO/ECNF electrodes can well work within −1 V to +1 V. Post-grown hierarchical pseudocapacitive nanostructures often suffer from their bad long-term cycling stability. In this work, a type of hierarchical partially-embedded MnO nanocube/electrospun carbon nanofiber composites (pe-MnO/ECNFs) was designed. Results show the MnO nanocubes are partially embedded into the ECNFs skeletons, showing a strong joint between them. The pe-MnO/ECNFs electrodes exhibit a high specific capacitance of 146 F g−1 (to the whole electrode mass) at scan rate of 5 mV s−1, and an ultralow decay rate of 0.004‰ per cycle for 20,000 cycles at 10 A g−1, which is much better than those of the MnO 2 /ECNF ones (96 F g−1, decay rate of 0.015‰ per cycle). Furthermore, the assembled flexible symmetric supercapacitors show an high energy density of 6.8 W h kg−1, a high dynamic bending stability, and a robust long cycling stability (low decay rate of 0.003‰ per cycle for 6000 cycles at 1 A g−1). [ABSTRACT FROM AUTHOR]