Sodium Alginate-Based Carbon Aerogel-Supported ZIF-8-Derived Porous Carbon as an Effective Adsorbent for Methane Gas.

Adsorption natural gas (ANG) is a technology in which natural gas is stored on the surface of porous materials at relatively low pressures, which are promising candidates for adsorption of natural gas. Adsorbent materials with a large surface area and porous structure plays a significant role in the ANG technology, which holds promise in increasing the storage density for natural gas while decreasing the operating pressure. Here, we demonstrate a facile synthetic method for rational construction of a sodium alginate (SA)/ZIF-8 composite carbon aerogel (AZSCA) by incorporating ZIF-8 particles into SA aerogel through a directional freeze-drying method followed by the carbonization process. The structure characterization shows that AZSCA has a hierarchical porous structure, in which the micropores originated from MOF while the mesopores are derived from the three-dimensional network of the aerogel. The experimental results show that AZSCA achieved high methane adsorption of 181 cm3·g-1 at 65 bar and 298 K, along with higher isosteric heat of adsorption (Qst) throughout the adsorption range. Thus, the combination of MOF powders with aerogel can find potential applications in other gas adsorption.

Konjac glucomannan/cellulose nanofibers composite aerogel supported HKUST-1 for CO2 adsorption.

Biomass aerogels are attractive in various applications owing to their inherent advantages of renewability, biodegradability and eco-friendly. Herein, a novel composite aerogel of konjac glucomannan (KGM)/TEMPO-oxidized cellulose nanofibers (TOCNF)@HKUST-1 (KTA@HKUST-1) is prepared through a facile vacuum impregnation method combined with the directional freeze-drying process, which using KGM and TOCNF as raw materials. The structural analyses disclose that the KTA@HKUST-1 has a hierarchical porosity, in which HKUST-1 can provide micropores for adsorption, while the meso-/macropores from KTA act as high-speed channels to improve diffusion and mass transfer rate to transport CO2 components into the micropores of HKUST-1. The experiment results of KTA@HKUST-1-10 (KTA@H10) show that the CO2 adsorption capacity can reach 3.50 mmol·g-1 at 1 bar and 298 K, and the adsorption capacity retention rate as high as 91.43% after 7 cycles. In addition, the CO2/N2 adsorption selectivity of KTA@H10 can reach 18.42, which has an excellent potential for selective CO2 adsorption.

Femtosecond laser modification of an array of vertically aligned carbon nanotubes intercalated with Fe phase nanoparticles.

Femtosecond lasers (FSL) are playing an increasingly important role in materials research, characterization, and modification. Due to an extremely short pulse width, interactions of FSL irradiation with solid surfaces attract special interest, and a number of unusual phenomena resulted in the formation of new materials are expected. Here, we report on a new nanostructure observed after the interaction of FSL irradiation with arrays of vertically aligned carbon nanotubes (CNTs) intercalated with iron phase catalyst nanoparticles. It was revealed that the FSL laser ablation transforms the topmost layer of CNT array into iron phase nanospheres (40 to 680 nm in diameter) located at the tip of the CNT bundles of conical shape. Besides, the smaller nanospheres (10 to 30 nm in diameter) are found to be beaded at the sides of these bundles. Some of the larger nanospheres are encapsulated into carbon shells, which sometime are found to contain CNTs. The mechanism of creation of such nanostructures is proposed.