Hybrid ZnAl‐LDH/CNTs nanocomposites: Noncovalent assembly and enhanced photodegradation performance

Abstract

In this article, we reported a facile and effective strategy for assembling hybrid ZnAl-layered double hydroxide/carbon nanotubes (ZnAl-LDH/CNTs) nanocomposites through noncovalent bonds, for the first time, in the presence of L-cysteine molecules. The materials have been characterized by powder X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), thermogravimetry and differential scanning calorimetry (TG-DSC), X-ray photoelectron spectra (XPS) and specific surface area measurement. The results indicate that L-cysteine as bridging linker plays a key role for enhancing both adhesion and dispersion of LDH nanocrystallites onto the surface of CNTs matrix through the interfacial interaction, and effectively inhibits the in situ growth of LDH crystallites, thus resulting in remarkably reduced LDH crystallite sizes; the Eu(III) fluorescence quenching in intercalated-Eu(III)complex LDH/CNTs nanocomposite can occur because of the interaction between LDH crystallites and CNTs matrix. Furthermore, it is found that as-assembled hybrid LDH/CNTs nanocomposites exhibit excellent performance for photodegradation of methyl orange molecules under UV irradiation, which is closely related to the unique hybrid nanostructure and composition of composites. V V C 2009 American Institute of Chemical Engineers AIChE J, 56: 768-778, 2010

Highly Efficient Visible Light-Induced O2 Generation by Self-Assembled Nanohybrids of Inorganic Nanosheets and Polyoxometalate Nanoclusters

“…Also the expansion of surface area upon hybridization with POM makes additional contribution to the observed improvement of photocatalytic activity through the provision of more reaction sites. The observed photocatalytic activity of the present Zn-Cr-LDH–POM nanohybrids is much higher than that of the previously reported Zn-Cr-LDH–layered titanate nanohybrids19, highlighting the superior role of POM nanoclusters as a coupling agent for improving the photocatalytic activity of the pristine LDH material. Taking into account somewhat similar surface areas of the Zn-Cr-LDH–POM and Zn-Cr-LDH–layered titanate nanohybrids, the observed merit of the hybridization with POM nanoclusters is surely attributable to more effective internal electron transfer of LDH with POM than with layered metal oxide.…”

“…One of the most effective ways to tailor the band structure of inorganic solids is to control their chemical composition89101112. A facile tailoring of the electronic structure via chemical substitution renders layered double hydroxide (LDH) a promising candidate for photocatalytic O 2 generation and CO 2 conversion13141516171819. In particular, Zn-Cr-LDH material receives prime attention because of its unusually high efficiency for visible light-induced O 2 production15.…”

“…Actually this LDH phase is one of the most active visible light photocatalysts for O 2 generation. In addition to the control of chemical composition, the hybridization with other semiconducting species is also fairly effective in optimizing the photocatalytic activity of the LDH materials through an expansion of the wavelength region of light absorption and an increase of electron–hole lifetime141519. Taking into account the fact that negatively charged polyoxometalate (POM) nanocluster can act as an effective electron acceptor for positively charged LDH nanosheets via a strong electrostatic interaction202122232425, the hybridization with POM species can provide a powerful way of further enhancing the photocatalytic activity of the Zn-Cr-LDH phase.…”

Direct growth of hydrotalcite nanolayers on carbon fibers by electrospinning

“…Nanometric sized hydrotalcites have been synthesized over different supports for a number of applications in gas permeable membranes (Lee et al, 2008), photodegradation (Wang et al, 2010), catalysis (Winter et al, 2005a(Winter et al, , 2005b and green chemistry (Álvarez et al, 2012, 2013). The broad applicability of these materials reflects the chemical versatility of the HT structure, which is constituted by positively charged brucite-like layers, neutralized by interlayer anions (Cavani et al, 1991;Evans and Duan, 2006).…”

Co-intercalation of Acid Red 337 and a UV Absorbent into Layered Double Hydroxides: Enhancement of Photostability

“…The second mass loss step, which shows a mass loss of 7.4% from 210 to 300°C, is due to the dehydroxylation of the LDH layers. 35 The third mass loss step is in the range of 300−800°C, and the exothermic peak at 463°C indicates the oxidative thermal decomposition of BP-4 anions. The mass loss of this stage is about 35.5%, which is less than the value of 45.8% calculated from the structural formula of LDH-0, suggesting that residue exists.…”