Sustainable and rapid preparation of nanosized Fe/Ni-pentlandite particles by mechanochemistry

Abstract

In recent years, metal-rich sulfides of the pentlandite type (M9S8) have attracted considerable attention for energy storage applications. However, common synthetic routes towards pentlandites either involve energy intensive high temperature...

Sustainability Assessment of Mechanochemistry by Using the Twelve Principles of Green Chemistry

“…[224] Therefore, real-time monitoring can help increasing the safety in mechanochemical reactions by providing information about a potential overpressure inside a milling container (preferentially in reactions initially carried out at a small scale), which could then be mitigated by addition of additives to scavenge volatile substances, [225] or by the selection of alternative starting materials. [226] On the other hand, the use of low-temperature ball milling protocols [130] could also offer the means to safely carry out exothermic mechanochemical reactions. Finally, it is important to stress the need to implement all safety precautions when working with energetic materials, since even realtime monitoring could provide data too late about internal changes in temperature and pressure of mechanochemical reactions.…”

“…For instance, temperature and pressure monitoring during the mechanosynthesis of N‐doped porous carbon from calcium carbide and trichlorotriazine enabled to observe a swift increase in pressure and temperature in the reaction, which was associated to the exothermicity of the process and to the formation of gaseous products [224] . Therefore, real‐time monitoring can help increasing the safety in mechanochemical reactions by providing information about a potential overpressure inside a milling container (preferentially in reactions initially carried out at a small scale), which could then be mitigated by addition of additives to scavenge volatile substances, [225] or by the selection of alternative starting materials [226] . On the other hand, the use of low‐temperature ball milling protocols [130] could also offer the means to safely carry out exothermic mechanochemical reactions.…”

Tailoring the Electrocatalytic Activity of Pentlandite FexNi9‐XS8 Nanoparticles via Variation of the Fe : Ni Ratio for Enhanced Water Oxidation

“…It is noteworthy mentioning that a minor amount (< 1 wt%) of ZrO 2 impurities exist with the produced pentlandite particles using this mechanochemical route as reported in our previous work. [30] However, they exist as isolated particles and are not integrated in the crystal lattice of pentlandite and thus do not influence the intrinsic properties of the material.…”

“…In a sustainable and simple procedure, Fe x Ni 9-X S 8 materials with distinct Fe : Ni ratios were successfully synthesized via a modified mechanochemical synthesis that is recently published by our group. [30] Briefly, reaction mixtures (total weight = 2.5 g) composed of stoichiometric amounts of the elements iron, nickel and sulphur were milled employing a planetary ball mill (Fritsch Pulverisette 7 premium line) with ZrO 2 milling containers (20 mL) and ZrO 2 milling balls (24 g, diameter = 2 mm). The reaction mixtures were prepared inside a glovebox to assure an inert argon atmosphere inside the milling vessels.…”

“…Additionally, an alternative to the classical time-consuming and wasteful high-temperature method for pentlandite synthesis [20,29] is mechanochemistry, which is a sustainable and versatile route for synthesis of nanosized pentlandites. [30][31][32] We have recently optimized the synthesis of Fe 4.5 Ni 4.5 S 8 using this method and demonstrated its performance in a continuousflow PEM-cell at a current density of 1 A cm À 2 at 1.95 V. [30] However, controlled and rapid mechanochemical synthesis of bimetallic pentlandites with different metal ratios has not yet been reported and these materials were not yet investigated for their potential to act as electrocatalysts for water oxidation.…”