1. Could you explain the significance of your article to the non-specialist? 

Ordered mesoporous carbons (OMC) is a unique family of porous materials that exhibit X-ray diffraction pattern due to the regular arrangement of uniform mesopores. This property makes OMC particularly suitable as a reference material in various researches on porous carbons. There are OMC with various pore structures, and the pore diameters are even tunable over the range of 2 - 15 nm. The chemical inertness, biocompatibility, and thermal stability as well as the uniform mesoporosity make them suitable as absorbents, catalysts, and host materials for various types of guest molecules. Separation and reuse of the solid nanoporous carbons materials have been an important issue in many of these applications. In the present work, we present a simple and effective one-pot synthesis strategy for the fabrication of OMC materials embedding ferromagnetic metal nanoclusters. Due to the soft ferromagnetism of the embedded metal nanoclusters, the OMC materials can easily be separated by applying a magnetic field. The magnetically separable carbon materials possessing uniformly nanoporous textures are promising for advanced applications including catalysis, sensors, nanoelectronics, drug delivery, etc.

2. What has motivated you to conduct this work? 

Mesoporous aluminosilicate is most widely used as a template for the synthesis of OMC, due to acid catalytic activity for the polymerization of carbon sources inside the template pores. Initially, we undertook the present work simply to investigate what happens if the Al catalyst is replaced by Co2+ or other transition metal ions. During the course of characterization work, we happened to find that the synthesized OMC samples were attracted by a magnet, due to the formation of Co nanoparticles in the carbon structure. However, we were disappointed by loss of the magnetic attraction when the OMC was used in acidic solutions. We therefore tried to develop methods to protect the Co nanoparticle. Interestingly, the simplest method, we found, was to repeat the infiltration of furfuryl alcohol in two steps as described in our paper.

3. Where do you see this work developing in the future? 

Co nanoparticles are not yet completely protected against acid leaching. Approximately, half the Co content was lost during washing with 1 M HCl. Research efforts in the near future will be directed to the development of synthesis routes that generate metal nanoparticles with enhanced ferromagnetism and chemical stability inside the OMC structure. For example, the Co particles can be further protected if synthesis conditions are optimised. New application possibilities of the OMC embedding ferromagnetic metal nanoclusters will be extensively explored. In addition to the application as a magnetically separable adsorbent or catalyst, the OMC materials might also be promising for the design of smart nanoelectronic devices that can response to the external electromagnetic field. As suggested by Professor Ferdi Schüth, the materials can be applied as a magnetically directed drug carrier, if a drug were loaded onto the porous carbon. The drug carrier can be directed to the target organ by applying an electromagnetic field and adsorbed drug can be released via the magnetic heating of ferromagnetic metal particles.

4. Are there any particular challenges facing future research in this area? 

For searching new possible applications of these materials, it is of prime importance to introduce diverse functional groups into the OMC structure, in addition to the ferromagnetic metal nanoparticles. For example, active sites for catalytic reaction and organic functional groups for molecular recognition can be combined with ferromagnetism of metal particles inside OMC structure, in order to fabricate magnetically separable catalysts and molecular sensors. For many practical applications, researches should also be carried out to develop a cost-effective and simple routes to such multifunctional materials.