Demonstrating the Simplicity and In Situ Temperature Monitoring of the Mechanochemical Synthesis of Metal Chalcogenides Suitable for Thermoelectrics

The scope of our research is the development of a transferable device capable of monitoring temperature inside the milling jar in a high-frequency manner and simultaneously demonstrating the simplicity of the mechanochemical synthesis on two examples of metal chalcogenides suitable for thermoelectric applications. Currently, metal chalcogenides are usually synthesized using multi-step, environmentally harmful methodologies, often using toxic precursor solvents and external heating. Mechanochemistry offers an environmentally sound, solvent-free alternative by milling the elemental precursors for a short time, which significantly improves the green chemistry metrics.

Precisely detecting the ignition time of MSR is challenging, since commercially available solutions do not collect data often enough and are costly. Our device overcomes this by collecting data every 80 milliseconds. It also tracks the jar's temperature during milling, autonomously assessing the time and temperature of the process.

These metal chalcogenides can be prepared within a second range by milling the elemental precursors. Monovert developed temperature monitoring device is transferrable to planetary ball mill jars cheap and much more frequent than of commercially available alternatives. Our findings underscore the environmentally sound and sustainable character of mechanochemical research and show its unique advantages in the inorganic chemistry field.

The developed temperature monitoring device might be interesting for a broad community of researchers working with planetary mills who need frequent information about temperature during milling. To begin, weigh 6.0055 grams of tin and 3.9945 grams of selenium to create a stoichiometric ratio of one to one with a total mass of 10 grams. Before milling, mix the tin and selenium powders thoroughly with a spatula to ensure homogeneity.

Now place the sensor board on top of the jar lid. Insert the sensor transistor into the small hole that passes through the lid. Then switch on the sensor device and connect it to the laptop software via Bluetooth.

Using tweezers, insert tungsten carbide balls into the milling jar as specified in the given table. Transfer the prepared sample to the tungsten carbide milling jar to synthesize tin selenide. Then close the milling jar with the lid set up with the sensor.

To load the jar into the mill, place the jar and the counterweight into the Pulverisette 7 premium line planetary ball mill, and set the milling parameters on the display. In the active software, type the sample's name, then press the start button on the milling display. After hearing the milling start, click start in the active software for the sensor to begin recording the temperature during milling.

When the mechanically induced self-propagating reaction occurs, indicated by a sudden increase in temperature, immediately stop the milling and the temperature measurement. The tin selenide samples showed temperature increases of about 3.8, 1.5, and 8.0 degrees Celsius after 87, 89, and 97 seconds of milling respectively.