Smart Solution Chemistry to Sn‐Containing Intermetallic Compounds through a Self‐Disproportionation Process

Abstract

Developing new methods to synthesize intermetallics is one of the most critical issues for the discovery and application of multifunctional metal materials; however, the synthesis of Sn-containing intermetallics is challenging. In this work, we demonstrated for the first time that a self-disproportionation-induced in situ process produces cavernous Sn-Cu intermetallics (Cu3 Sn and Cu6 Sn5 ). The successful synthesis is realized by introducing inorganic metal salts (SnCl2 ⋅2 H2 O) to NaOH aqueous solution to form an intermediate product of reductant (Na2 SnO2 ) and by employing steam pressures that enhance the reduction ability. Distinct from the traditional in situ reduction, the current reduction process avoided the uncontrolled phase composition and excessive use of organic regents. An insight into the mechanism was revealed for the Sn-Cu case. Moreover, this method could be extended to other Sn-containing materials (Sn-Co, Sn-Ni). All these intermetallics were attempted in the catalytic effect on thermal decompositions of ammonium perchlorate. It is demonstrated that Cu3 Sn showed an outstanding catalytic performance. The superior property might be primarily originated from the intrinsic chemical compositions and cavernous morphology as well. We supposed that this smart solution reduction methodology reported here would provide a new recognition for the reduction reaction, and its modified strategy may be applied to the synthesis of other metals, intermetallics as well as some unknown materials.

Interfacial Doping of Heteroatom in Porous SnO2 for Highly Sensitive Surface Properties

“…Lower surface area with higher performance indicates the existence of abundant activity species. Cu species showed superior activity in AP decomposition than Ni species in our previous study, 24 and the accelerated electron transfer of Cu species may be the major factor for enhanced performance. It appears that metal-doped porous SnO 2 is a multifunction material for gas catalysis as well as solid catalysis.…”

“…To make clear the transformation process for diverse porous SnO 2 , we prepared four kinds of Sn-containing intermetallic compounds (Cu 3 Sn, Cu 6 Sn 5 , Sn–Ni, and Sn–Co) following the procedure reported in our previous work. 24 These intermetallic compounds were taken as precursors for the transformation, which underwent an oxidization reaction in O 2 atmosphere and a subsequent acid etching by hydrothermal condition. Prior to the oxidization reaction, the optimum oxidation temperature of the precursors was initially determined by thermogravimetric analysis (TGA)–differential scanning calorimeter (DSC) data analysis.…”

“…The key to this route is the transformation reaction. To make clear the transformation process for diverse porous SnO 2 , we prepared four kinds of Sn-containing intermetallic compounds (Cu 3 Sn, Cu 6 Sn 5 , Sn–Ni, and Sn–Co) following the procedure reported in our previous work . These intermetallic compounds were taken as precursors for the transformation, which underwent an oxidization reaction in O 2 atmosphere and a subsequent acid etching by hydrothermal condition.…”

“…These precursors were prepared by a hydrothermal method, just following the procedure we recently reported. 24 Second, the precursors of Cu 6 Sn 5 , Cu 3 Sn, Sn−Ni, and Sn−Co were transformed into a series of oxides named as SC1-800, SC2-800, SN-800, and SCo-800, respectively, through an oxidization reaction under O 2 atmosphere at 800 °C for 2 h. Afterward, 30 mL of 0.3 M HNO 3 aqueous solution was added to form a mixed solution, which was transferred to an autoclave with a Teflon liner and heated at 140 °C for 2 h. The sample after hydrothermal crystallization was centrifuged and washed with abundant distilled water. Then, variations of porous SnO 2 (named as SC1-800H, SC2-800H, SN-800H, and SCo-800H) were obtained after drying at 70 °C for precursors of Cu 6 Sn 5 , Cu 3 Sn, Sn−Ni, and Sn−Co, respectively.…”

Microstructure and Optical Properties of Nanostructural Thin Films Fabricated through Oxidation of Au–Sn Intermetallic Compounds

“…Moreover, in contrast to alloys, IMCs provide well-defined stoichiometry, atomic arrangements, and unique electronic and geometric structures, and can therefore be used as low-cost catalysts with tailored performance [ 5 ]. The advanced properties of IMCs are directly associated with the newly formed chemical bonds between diverse metal atoms, which subsequently affect the electronic environment and surface active sites in relevant reactions that are crucial for catalytic and sensor applications [ 53 , 54 ].…”