Single gyroid-structured metallic nanoporous spheres fabricated from double gyroid-forming block copolymers via templated electroless plating

Abstract

Herein, we suggest a methodology for the fabrication of well-defined metallic nanoporous spheres with single gyroid (SG) structure by simply using self-assembled diblock copolymer with double gyroid (DG) structure as a template for electroless plating. Note that owing to the consideration of thermodynamic stability, the self-assembly of diblock copolymers gives rise to a DG phase instead of an SG phase. By controlling the nucleus density for the reduction of Pd ions within the diblock copolymer template, SG-structured Ni can be easily fabricated through the nucleation and growth processes. Consequently, nanoporous Ni spheres with uniform pore sizes and high specific surface areas can be fabricated. Moreover, nanoporous Ni spheres with controlled microscale particle sizes can thus be obtained by controlling the reduction time for the growth of Ni, which enables the feasibility of recyclability via magnetic fields. The combination of structural and morphological characteristics of the fabricated nanoporous Ni spheres make them appealing for use in a wide variety of applications, such as high-efficiency and well selectivity hydrogenation catalysts with recyclability due to their narrow pore size distributions, high specific surface areas, 3D curved surfaces, and controlled microscale particle sizes.

Three-Dimensional Nanoporous Metal Structures from Poly(2-vinylpyridine)-block-Poly(4-vinylpyridine) Copolymer Thin Film

“…Since Pt and Pt/another metal composite nanostructures have been widely used for catalyst, − we also prepared 3D nanoporous Pt structures. Figure gives SEM images of 3D nanoporous Pt structures after immersing P24VP thin film into Pt precursor solution for different times, followed by the complete removal of P24VP thin film O 2 RIE.…”

Electron Crystallographic Investigation of Crystals on the Mesostructural Scale

“…The concept of the crystals on a mesostructural scale is based on a periodic structure with the unit cell parameters ranging from nanometer scale to sub-micron. Relevant structures have been widely found in nature and artificial systems, such as butterfly wing scales (Saranathan et al, 2010; Winter et al, 2015; Corkery & Tyrode, 2017; Wilts et al, 2017), exoskeleton of beetles/weevils (Galusha et al, 2008; Wilts et al, 2012), mineralization templated from the natural species (Galusha et al, 2010; Mille et al, 2011, 2013; Wu et al, 2018), superstructures of inorganic nanoparticles (Zhang et al, 2017), self-assembly of surfactants and block copolymers and their inorganic replicas (Finnemore et al, 2009; Han et al, 2009, 2011, 2014 b , Hsueh et al, 2014; Cao et al, 2016; Li et al, 2017; Mao et al, 2017; La et al, 2018; Yang et al, 2019; Lin et al, 2020), etc. Compared to the traditional atomistic crystal structures, these mesostructured crystals contain highly organized networks or cavities arranged periodically and sometimes possess amorphous (or metal, metallic oxide, etc.)…”

Visualizing Magnetic Structure in 3D Nanoscale Ni–Fe Gyroid Networks

“…Because the two gyroid networks in the double-gyroid are physically separate (only coupled magnetostatically), it is possible for nanoscale local variations (e.g., in the density of Ni 75 Fe 25 nanoparticles in the seeding step) to favor the growth of one network over the other. 53 It is therefore possible to increase the likelihood of single-gyroid regions by restricting the amount of Ni 75 Fe 25 deposited into the gyroid polymer template during constantpotential growth, via limiting the total charge supplied by the potentiostat. Figure 3a shows a double-gyroid nanoparticle from a sample deposited with a total charge of 20 mC, whereas in Figure 3c, the sample was deposited with a total charge of only 5 mC, showing a (111)-oriented nanoparticle containing a double-gyroid region and a single-gyroid region, allowing the properties of a single-gyroid network to be studied, as well.…”

“…Electron micrographs of the PFS-free samples in Figure a,c show isolated gyroid nanoparticles around 150 nm across, the deliberate fabrication of which satisfies the requirement of off-axis EH of free space around the sample for the reference wave and also allows variations in sample morphology to be studied. Because the two gyroid networks in the double-gyroid are physically separate (only coupled magnetostatically), it is possible for nanoscale local variations (e.g., in the density of Ni 75 Fe 25 nanoparticles in the seeding step) to favor the growth of one network over the other . It is therefore possible to increase the likelihood of single-gyroid regions by restricting the amount of Ni 75 Fe 25 deposited into the gyroid polymer template during constant-potential growth, via limiting the total charge supplied by the potentiostat.…”