High electrochemical activity from hybrid materials of electrospun tungsten oxide nanofibers and carbon black

Abstract

Tungsten oxide (WO 3 ) nanofibers were prepared by oxidizing the electrospun ammonium metatungstate (AMT) and polyvinyl pyrrolidone (PVP) composite fibers. The WO 3 nanofibers with controllable diameters ranging from 80 to 130 nm were obtained by electrospinning different AMT/PVP mixture solutions. Electrochemical activity of the WO 3 nanofibers was measured in 0.5 M sulfuric acid solution. Cyclic voltammetry tests show that the WO 3 nanofibers have electrochemical activity which is closely related to hydrogen oxidation in fuel cells and the electrochemical activity could be greatly enhanced by the addition of carbon black. The hybrid materials of the WO 3 nanofibers and carbon black with the WO 3 :C mass ratio of 10:1 possess high electrochemical activity with an anodic peak current density of 11.2 mA/cm 2 , even higher than the commercial 20 wt% Pt/C catalyst. The electrospun WO 3 nanofibers may be promising electrocatalysts or catalyst supports for hydrogen oxidation in fuel cells due to the simplicity in production and high electrochemical activity.

Nanoscale Colocalization of Fluorogenic Probes Reveals the Role of Oxygen Vacancies in the Photocatalytic Activity of Tungsten Oxide Nanowires

“…[62][63][64] PVP aids in the colloidal stability and dispersibility of metal oxide particles. Tungsten oxide nanowires with PVP on their surface have been used as photocatalysts and electrocatalysts, [65][66] but the effect of the PVP coating on their activity has not been studied.…”

Potential-mediated growth of ultrathin hydrated tungsten oxide nanosheets with high electrochemical activity from amorphous precursor nanofibers

“…4c, it is found that the current density of the sample prepared at -0.15 V from the precursor nanofibers calcined at 400°C increases by 10, 7, and 4.7 times than the amorphous precursor nanofibers calcined at 400°C, the crystalline WO 3 nanofibers calcined at 450°C, and the commercial 20 wt% Pt/C catalyst, respectively. The current density obtained for the HWO nanosheets is much higher than other WO 3 nanostructures reported previously [4,8,21,24]. It is believed that the high electrochemical activity of the obtained samples and its changing trend with the applied potential result from the formation and structure changes of the nanosheets.…”

“…The electrospinning solutions were prepared by dissolving AMT and PVP in distilled water at the concentrations (w/v) of 6 and 7 %, respectively, where AMT acts as tungsten source for hydrated WO 3 nanosheets and PVP acts as the thickener for electrospinning. The AMT/PVP composite nanofibers were electrospun at 40 kV from the AMT/PVP solution by a conventional setup [24]. Afterwards, the AMT/PVP composite nanofibers were calcined at 400°C for 3 h in a tube furnace in O 2 atmosphere, obtaining the nanofibers with amorphous structure, which were used as the precursor nanofibers for growing the HWO nanosheets.…”

“…Many methods have been developed for preparing WO 3 nanomaterials such as electrochemical anodization [18], hydrothermal [4,19,20], sol-gel [21], thermal evaporation [22,23], templating [8], and electrospinning [24] methods. A rich variety of WO 3 nanostructures such as nanoporous films [18], nanowires [14,19,22,23], nanowire network [22], nanosheets [4,17,19,20], and nanotrees [25] have been successfully synthesized.…”

Glucose sensors based on electrospun nanofibers: a review

“…Several efforts have been successfully forwarded by various research groups for the efficient preparation of metal oxide nanofibers using electrospinning method. The resulting outcome emphasized the emergence of the electrospinning method to be a compelling technique for the construction of composite and inorganic nanofibers that has various applications including glucose sensor [183][184][185][186][187][188][189][190][191][192][193][194][195][196][197]. Metal oxide nanofibers are prepared in a two-step procedure (i.e., first the organic phase in composite nanofibers is removed via calcinations at high temperature).…”