Unusual Hollow Al₂O₃ Nanofibers with Loofah-Like Skins: Intriguing Catalyst Supports for Thermal Stabilization of Pt Nanocrystals

Abstract

Recently, hollow nanofibers could be fabricated by coaxis electrospinning method or template method. However, they are limited to applications because of the hardship in actual preparation. In this work, hollow γ-AlO nanofibers with loofah-like skins were first fabricated by using a single spinneret during electrospinning. These intriguing nanofibers were explored as new Pt supports with excellently sinter-resistant performance up to 500 °C, attributed to the unique loofah-like surface of γ-AlO nanofibers and the strong metal-support interactions between Pt and γ-AlO. When applied in the catalytic reduction of p-nitrophenol, the Pt/γ-AlO calcined at 500 °C exhibited 4-times higher reaction rate constant (6.8 s·mg) over free Pt nanocrystals.

In situ growth of hierarchical Al2O3 nanostructures onto TiO2 nanofibers surface: super-hydrophilicity, efficient oil/water separation and dye-removal

“…These fine-structures arise from more nucleation centers with smaller crystallite size and higher charge density during electrospinning [26,27]. Besides, Al 2 O 3 nanocrystals prefer to form at the surface of the nanofibers owing to thermal decomposition of Al(acac) 3 under the existence of an oxygenrich area [24]. The average diameter of Al 2 O 3 /TiO 2 nanofibers slightly increased when more Al 2 O 3 was introduced (figure S4), which can be attributed to the migration of Al 2 O 3 outward during calcination.…”

“…However, pore-generating agents have to be removed completely before using to restore clean surface by additional treatment, such as combustion. During such heat treatment, the porous metal oxide commonly suffers from tremendous shrinkage and deformation, and thus lost its surface areas dramatically, as a result of undesirable sintering [24]. Our previous work observed the porous electrospun Al 2 O 3 nanofibers lost most surface area from 180.2 to 46.8 m 2 g −1 during calcination in air [24].…”

“…During such heat treatment, the porous metal oxide commonly suffers from tremendous shrinkage and deformation, and thus lost its surface areas dramatically, as a result of undesirable sintering [24]. Our previous work observed the porous electrospun Al 2 O 3 nanofibers lost most surface area from 180.2 to 46.8 m 2 g −1 during calcination in air [24]. Therefore, exploring new approach that can generate rational-designed metal oxide nanostructures with abundant adsorption sites is still a daunting challenge.…”

Recent Advances in Applications of Ceramic Nanofibers

“…The unique properties of CNFs such as high surface area, extraordinary length, low density, high porosity, and thermo-mechanical properties [40,41] qualify them for many different applications. This chapter covers a review of their applications related to tissue engineering [35,36,[42][43][44][45][46][47], sensors [32-34, 48, 49], water remediation [50][51][52][53][54][55][56], batteries [57][58][59][60][61][62][63], catalyst supports/catalysts [64][65][66][67][68][69][70][71], electromagnetic interference (EMI) shielding [72][73][74][75][76][77][78][79], and thermal insulation materials [26,[79][80][81][82], etc. A list of the recent studies about ceramic nanofibers by electrospinning method is presented in Table…”

Au–Ag and Pt–Ag bimetallic nanoparticles@halloysite nanotubes: morphological modulation, improvement of thermal stability and catalytic performance

“…15 Impressively, the interaction between metal nanoparticles and support surface may signicantly enhance the thermal stability of metallic catalysts. 16 Mesoporous supports with different Si/Al ratios have demonstrated distinct catalytic activities due to their different densities of active defects which play a key role in stabilizing and activating metal nanoparticles. 17 Halloysite, a kind of natural clay (chemical composition: Al 2 Si 2 O 5 (OH) 4 $nH 2 O, 1 : 1 layer aluminosilicate) with tubular nanostructure, is promising as a catalyst support.…”