Pradip Pachfule

Fabrication of carbon nanorods and graphene nanoribbons from a metal–organic framework

One- and two-dimensional carbon nanomaterials are attracting considerable attention because of their extraordinary electrical, mechanical and thermal properties, which could lead to a range of important potential applications. Synthetic processes associated with making these materials can be quite complex and also consume large amounts of energy, so a major challenge is to develop simple and efficient methods to produce them. Here, we present a self-templated, catalyst-free strategy for the synthesis of one-dimensional carbon nanorods by morphology-preserved thermal transformation of rod-shaped metal-organic frameworks. The as-synthesized non-hollow (solid) carbon nanorods can be transformed into two- to six-layered graphene nanoribbons through sonochemical treatment followed by chemical activation. The performance of these metal-organic framework-derived carbon nanorods and graphene nanoribbons in supercapacitor electrodes demonstrates that this synthetic approach can produce functionally useful materials. Moreover, this approach is readily scalable and could be used to produce carbon nanorods and graphene nanoribbons on industrial levels.

From covalent–organic frameworks to hierarchically porous B-doped carbons: a molten-salt approach

B-doped porous carbons have attracted attention in energy applications including gas and energy storage due to the increase of binding energy for H2 and lowering the Fermi level. However, B-doped carbons are usually microporous materials, which show low surface areas. Herein, for the first time, hierarchically porous B-doped carbons derived from COF-5 have been obtained via a molten-salt (MS) approach. The carbons with micro–meso–macro-porous architectures exhibit enhanced supercapacitive performance and H2 storage properties. The methodology described may open up a new avenue towards the synthesis of distinct carbon materials in liquid media.

From Ru nanoparticle-encapsulated metal–organic frameworks to highly catalytically active Cu/Ru nanoparticle-embedded porous carbon

A facile method for the in situ encapsulation of highly dispersed ultrafine Ru nanoparticles in HKUST-1, a copper–1,3,5-benzenetricarboxylate (BTC) metal–organic framework (MOF), without aggregation on the external surface of MOF crystallites has been developed. The thermal transformation of Ru@HKUST-1 composites in an inert atmosphere has yielded ultrafine Cu/Ru nanoparticle-embedded porous carbon, which shows very high catalytic activity and good durability for ammonia borane hydrolysis. During the thermal treatment of Ru@HKUST-1 composites, highly graphitic carbon formed around the Cu/Ru nanoparticles depressed the sintering of nanoparticles, resulting in the fine distribution of tiny nanoparticles in the carbon matrix. For the first time, the utilization of metal nanoparticle-encapsulated MOFs as a template/precursor for the synthesis of catalytically active metal nanoparticle-embedded porous carbon has been revealed.