Nanocrystalline BEA-CNT Composites with High Metal Dispersion Obtained via Inter-Zeolite Transformation for Antibacterial Application

Abstract

The rational design of interface materials containing carbon nanotubes (CNTs) and zeolites (zeolite-CNTs) is a promising perspective in chemical and biochemical communities because they exhibit several outstanding properties such as tunable hydrophobicity−hydrophilicity at interfaces. In this contribution, we report the fabrication of Ag-incorporated nanocrystalline BEAcarbon nanotube (CNT) composites via the one-pot inter-zeolite transformation of the micron-sized FAU-CNT composite in the presence of a Ag precursor. By varying the crystallization time, the inter-zeolite transformation mechanism was explored. Indeed, this process involves an amorphous intermediate of aluminosilicate species with a significant change of the crystal morphology in the presence of CNTs in the synthesis gel. Interestingly, the redispersion of metal particles was observed after the inter-zeolite transformation process, resulting in the high dispersion of metal nanoparticles over BEA nanocrystals. Notably, it was revealed that the Ag sites were also stabilized in the presence of CNT interfaces, leading to the availability of highly active Ag + ions. To illustrate the beneficial aspect of designer materials, the synthesized Ag-incorporated BEA-CNT composites exhibited high antibacterial activity againstEscherichia coli due to the synergistic effect of the active Ag + species and appropriate hydrophobic and hydrophilic properties of the hybrid material interfaces. This first example opens up perspectives of the rational design of zeolite−CNT interfaces with high metal dispersion via the inter-zeolite transformation approach for biomedical applications.

Modification of Zeolite Morphology via NH4F Etching for Catalytic Bioalcohol Conversion

“…All ZSM-5 samples exhibited a combination of Type I and Type IV adsorption isotherms, as evidenced by the hysteresis loops indicative of both microporous and mesoporous materials (Figure 3A). [32] Notably, the ZSM-5 samples subjected to treatment with 20 and 30 wt % NH 4 F displayed significantly larger hysteresis loops compared to their counterparts. This observation is attributed to the substantially increased mesoporosity resulting from the fluoride etching process, as clearly demonstrated in Figure 3A.…”

Perspectives on Recent Advances in Hierarchical Zeolites for Bioethanol Conversion to Chemicals, Jet Fuels, and Carbon Nanotubes

“…Interestingly, NiAl-MOR containing CNTs materials were used as the electrode in HMF oxidation, which exhibited 100% of 5-Hydroxymethylfurfural (HMF) conversion with 92% yield of 2,5-furandicarboxylic acid (FDCA). In addition, Iadrat and co-workers successfully synthesized carbon nanotubes (CNTs) with an average outer diameter of 13.80 ± 3.47 nm after 15 min of growth duration at 800 °C using the Fe/FAU catalyst. Extending the growth time to 60 min significantly increased the yield of obtained CNTs (CNTs-Fe-FAU) from 9.96% to 27.71%, with an insignificant increase in the average outer diameter to 16.98 ± 2.95 nm.…”