Facile synthesis of micron‐sized hollow copper spheres with ZSM‐5 molecular sieve as a template

Abstract

A new, well-designed type of micron-sized hollow copper spheres was synthesized in this article. The process was performed using ZSM-5 molecular sieve as a template. It has the prominent advantage in that the various stages of pretreatment for the core material can be omitted because of the inherent nature of the ZSM-5 molecular sieve. The surface of the sieve consists entirely of negatively charged oxygen sites such that free Cu 2+ ions can easily be adsorbed and reduced there, acting thereafter as a seed and self-catalyst for electroless plating of copper so as to lead to the formation of interconnected Cu particles around the external surface of the ZSM-5 molecular sieve. Moreover, there are many holes with a size of more than 5 × 5 Å 2 on the surface of the ZSM-5 molecular sieve, which can act as concavities that the reduced Cu can 'rivet' into, resulting in the link between the molecular sieve and the reduced Cu being stronger. In addition, the ZSM-5 molecular sieve has the merits of ease of removal, low cost, and less aggregation owing to its micrometer size, and it avoids the use of nonvolatile surfactants, which may be adsorbed onto the reduced Cu and then interfere with the possible application of the hollow copper spheres in catalysis and in analytical devices based on surface-enhanced Raman scattering (SERS) spectroscopy. The copper spheres obtained show enhanced Raman scattering in the presence of adsorbed 4-mercaptobenzoic acid (4-MBA) with excitation at 632.8 nm, and the enhancement factor reaches ∼7 × 10 3 . The new micron-sized hollow copper spheres are produced in a simple and cost-effective method; so they are expected to play an important role in the fields of catalysts, fillers, and engineering, and in the development of SERS-based analytical devices. The synthetic method may represent a novel route to prepare hollow metal spheres, which is a subject of intense interest.

Degradation of dyes using hollow copper microspheres as catalyst

“…The micron-sized hollow copper spheres were prepared referencing our previous work [8]. Initially, 70 mg of ZSM-5 molecular sieve was poured, under continuous mechanical agitation, into 10 mL of an aqueous solution containing 120 mg of sodium hydroxide, 660 mg of EDTA, and 420 mg of copper sulfate pentahydrate, and the mixture was left for 5 min to form a suspension.…”

“…However, in contrast to the successful syntheses of polymer, oxide, and semiconductor products, developing a template-based synthesis of hollow metal spheres remains a great challenge, possibly because of the difficulty of removing the templates without breaking the shells [5]. Very recently, we developed a new method to prepare hollow copper microspheres, which used ZSM-5 molecular sieve as a template [8]. The ZSM-5 molecular sieve has the merits of ease of removal and low cost.…”

Recent advances in linear and nonlinear Raman spectroscopy. Part IV

“…The authors found that the modification of UPD Ag can significantly reduce the thermal destruction of SERS-active substrates. A new type of micrometer-sized hollow copper sphere was reported by Xia et al [16] The process involves using ZSM-5 molecular sieve as a template such that at various stages of pretreatment the core material can be omitted because of the inherent nature of the ZSM-5 molecular sieve. Alexander et al [17] presented a high-throughput method for fabricating large arrays of SERS-active gold dimers.…”

“…Wermelinger and Spolenak [194] investigated the microstructure changes upon indentation of single-crystalline (100)-oriented silicon by transmission electron microscopy and Raman microscopy. Thermo-Raman spectroscopy was used by Frost et al [195] to characterize selected layered double hydroxides of formula Cu 6 Al 2 (OH) 16 CO 3 and Zn 6 Al 2 (OH) 16 CO 3 . Kumar et al [196] characterized the structure of the lead-free relaxor Ba(Ti 0.70 Sn 0.30 )O 3 using micro-Raman spectroscopy from 80 to 500 K, which indicated three local phase sequences.…”

Synthesis of hollow polypyrrole-platinum complex spheres and their successful application as a catalyst for decomposition of hydrogen peroxide

“…In addition, the use of non volatile surfactants can be avoided, which may be adsorbed onto the synthesized pyrrole-platinum poly (PPy-Pt) complex spheres and interfere with their possible applications in catalysis. Very recently, we developed a new method for preparation of silver core-shell materials and hollow materials by using 5A and ZSM 5 molecular sieves as templates [14,15]. To the best of our knowledge, there have been few reports on preparation of hollow conductive PPy spheres based on surface modified molecular sieves.…”