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Design of economical, large-scale, stable, and highly active bifunctional electrocatalysts for Zn-air batteries with enhanced oxygen reduction and oxygen evolution performance is needed. Herein, a series of electrocatalysts were facilely fabricated where in situ formed bimetallic nanoparticles aided in the growth of carbon nanotubes over carbon nanofibers (MM'-CNT@CNF) during thermal treatment. Different combinations of Fe, Ni, Co and Mn metals and melamine as precursor for CNT growth were investigated. The synergistic interaction between bimetallic nanoparticles and N-doped carbon results in greatly improved bifunctional catalytic activity for both oxygen reduction and evolution reactions (ORR, OER) using FeNi-CNT@CNF as catalyst. The half-wave potential (0.80 V vs. RHE) for FeNi-CNT@CNF for ORR was close to that of Pt/C (0.79 V vs. RHE), meanwhile its stability was superior to Pt/C. Likewise, during OER, the FeNi-CNT@CNF reached a current density of 10 mA cm-2 at a rather low overpotential of 310 mV vs. RHE compared to benchmark RuO2 (410 mV). The rechargeable Zn-air prototype battery using FeNi-CNT@CNF as an air electrode outperformed the mixture of Pt/C and RuO2 with discharge/charge overpotential of 0.61 V, power density of 118 mW cm-2 at 10 mA cm-2 and an improved cycling stability over 108 hours.

Here, we report synergistic sensitization of electrospun TiO2 nanofibers (TNFs) by heterojunction formation with exfoliated g-C3N4 nanosheets and decorated with Ag nanoparticles (NPs) uniformly over its surface for enhanced photocatalytic activity in simulated solar light. These composite catalysts displayed first-order rate constants of 0.087 min(-1) and 0.031 min(-1) for photodegradation of methylene blue (MB) and photoreduction of Cr(VI) under simulated sunlight which is 75% and 87% higher than the pristine TNFs, respectively, and better than the previously reported results for similar materials. Moreover, 99% of E. coli. and 83% S. aureus were inactivated after 60 min of irradiation. The enhanced activities of these prepared ternary composite nanofibers are attributed to the effective Z-scheme heterojunction formation between TiO2 and g-C3N4 due to the preferred band positions which facilitates the charge transfer and inhibit the recombination of charge carriers. Moreover, visible-light harvesting, charge separation and antimicrobial nature of these nanofibers were promoted by the Ag NPs due to the surface plasmon resonance (SPR) effect.

Polymer nanocomposites containing pristine (PCNF) and amine-functionalized (NFCNF) electrospun carbon nanofibers were fabricated. The amine-terminated functional groups on CNFs, with a surface coverage of 2.76 mmol/g, react with the epoxy monomers forming covalent linkages for better dispersion and stronger interface. The improved load transfer resulted in an improvement of 82% in storage modulus (rubbery region similar to 70 degrees C) and 20 degrees C increase in the glass transition temperature for 1 wt% NFCNF-epoxy. Tensile strength and modulus improves by 22% and 27%, respectively, for 2 wt% NFCNF-epoxy. The thermal stability, dielectric properties and AC/DC conductivity are discussed in terms of the interfacial characteristics. These results highlight the potential of electrospun CNFs as structural and functional reinforcement., Higher Education Commision, Pakistan [4430, 5911], Higher Education Commision, Pakistan, Grant/Award Numbers: 4430, 5911

Here, we report synergistic sensitization of electrospun TiO2 nanofibers (TNFs) by heterojunction formation with exfoliated g-C3N4 nanosheets and decorated with Ag nanoparticles (NPs) uniformly over its surface for enhanced photocatalytic activity in simulated solar light. These composite catalysts displayed first-order rate constants of 0.087 min(-1) and 0.031 min(-1) for photodegradation of methylene blue (MB) and photoreduction of Cr(VI) under simulated sunlight which is 75% and 87% higher than the pristine TNFs, respectively, and better than the previously reported results for similar materials. Moreover, 99% of E. coli. and 83% S. aureus were inactivated after 60 min of irradiation. The enhanced activities of these prepared ternary composite nanofibers are attributed to the effective Z-scheme heterojunction formation between TiO2 and g-C3N4 due to the preferred band positions which facilitates the charge transfer and inhibit the recombination of charge carriers. Moreover, visible-light harvesting, charge separation and antimicrobial nature of these nanofibers were promoted by the Ag NPs due to the surface plasmon resonance (SPR) effect.

Polymer nanocomposites containing pristine (PCNF) and amine-functionalized (NFCNF) electrospun carbon nanofibers were fabricated. The amine-terminated functional groups on CNFs, with a surface coverage of 2.76 mmol/g, react with the epoxy monomers forming covalent linkages for better dispersion and stronger interface. The improved load transfer resulted in an improvement of 82% in storage modulus (rubbery region similar to 70 degrees C) and 20 degrees C increase in the glass transition temperature for 1 wt% NFCNF-epoxy. Tensile strength and modulus improves by 22% and 27%, respectively, for 2 wt% NFCNF-epoxy. The thermal stability, dielectric properties and AC/DC conductivity are discussed in terms of the interfacial characteristics. These results highlight the potential of electrospun CNFs as structural and functional reinforcement., Higher Education Commision, Pakistan [4430, 5911], Higher Education Commision, Pakistan, Grant/Award Numbers: 4430, 5911