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• Keratin-based solution has good fiber-forming ability. • Post-functional strategy by glutaraldehyde (GTA) has two functions. • A novel keratin-based separator with high ionic conductivity and good stability. • Device with keratin-based separator exhibits outstanding electrochemical performance. Keratin is one of natural polymers with super wettability, which is an alternative sustainable polymer to fabric separators for high-performance supercapacitors (SCs). However, the extracted keratin has poor fiber-forming ability, and it remains challenging to prepare high performance keratin-based separators. In this study, to overcome the conflict between good mechanical strength and high ionic conductivity, keratin-based nanofiber membranes were prepared by electrospinning and glutaraldehyde (GTA) post-function strategy, which endow high mechanical strength (7.87 MPa) and high ionic conductivity (2.21 mS/cm) to keratin-based membranes (KMs-8). The FTIR and XRD approved that GTA treatment has two functions, i.e., cross-linking reaction and oxidation reaction, which endow the membranes with connected crosslinking sited structure and with hydrophilic groups in comparison with unfunctionalized membrane. As expected, the SCs with KMs-8 separator exhibit outstanding electrochemical performances with high specific capacitance (173.68F g−1) and good cyclic stability (98.1% at 8000 cycles). This research provides new insight into the design of keratin-based separator for SCs, which will broaden the application range of keratin and suggest a sustainable natural polymer for the utility for energy-related devices. [ABSTRACT FROM AUTHOR]

Abstract: Electrospun anatase-phase TiO2 nanofibers with desired morphological structure and relatively high specific surface area are expected to outperform other nanostructures (e.g., powder and film) of TiO2 for various applications (particularly dye-sensitized solar cell and photo-catalysis). In this study, systematic investigations were carried out to prepare and characterize electrospun anatase-phase TiO2 nanofibers with different morphological structures (e.g., solid, hollow/tubular, and porous) and specific surface areas. The TiO2 nanofibers were generally prepared via electrospinning of precursor nanofibers followed by pyrolysis at 500°C. For making hollow/tubular TiO2 nanofibers, the technique of co-axial electrospinning was utilized; while for making porous TiO2 nanofibers, the etching treatment in NaOH aqueous solution was adopted. The results indicated that the hollow/tubular TiO2 nanofibers (with diameters of ∼300–500nm and wall-thickness in the range from tens of nanometers to ∼200nm) had the BET specific surface area of ∼27.3m2/g, which was approximately twice as that of the solid TiO2 nanofibers (∼15.2m2/g) with diameters of ∼200–300nm and lengths of at least tens of microns. Porous TiO2 nanofibers made from the precursor of Al2O3/TiO2 composite nanofibers had the BET specific surface area of ∼106.5m2/g, whereas porous TiO2 nanofibers made from the precursor of ZnO/TiO2 composite nanofibers had the highest BET specific surface area of ∼148.6m2/g. [Copyright &y& Elsevier]

In this study, we prepared wool keratin/PET composite nanofiber membrane to adsorb the Cr(VI) in acidic solution due to its strong adsorption ability. The adsorption ability of the composite membrane with different ratios of keratin to PET was investigated. The optimum adsorption ability can be obtained when the keratin concentration was 50% in the solution with a pH value of 3. With the higher content of keratin, the membrane possessed higher hydrophilicity, larger pore ratio, and larger extent amino protonation. The maximum adsorption ability of the composite membranes was 75.86 mg/g, while that of the pure PET nanofiber membrane was 27.27 mg/g. The FTIR and XPS analysis results demonstrated that both the disulfide bond of the keratin and the amino were involved in the adsorption process. The process was achieved by the electrostatic adsorption of the amino and the redox reaction of disulfide bond in cystine oxide. The removal property of the electrospun keratin/PET composite membrane was 75.86 mg/g. Unlabelled Image • PET composite nanofiber membrane with keratin extracted from wool was used for Cr(VI) adsorption. • The nanostructured fiber membrane with keratin promotes adsorption and reuse. • The adsorption mechanism has been proposed and explained the full reversibility in the adsorption process. [ABSTRACT FROM AUTHOR]