The invention is a new method for preparing hafnium carbide nanomaterial by one-step chemical reaction under mild conditions, the production equipment required by the production process is simple, the temperature required by the reaction is low, the raw material source is wide and cheap, the operation is simple, and the synthesis of hafnium carbide nanomaterial is realized by one-step chemical reaction.
The reaction principle of the adopted technical scheme is as follows:
hfo2+2mg→2mgo+hf*
li2co3+3mg→2mgo+c+2li
hf*+c*→hfc
The beneficial effect is that the hafnium carbide nanomaterial is prepared by the reoxidation reduction reaction between metal m and carbonate and hafnium dioxide in a closed system. The reaction temperature is lower than that of the prior art, the raw materials used in the reaction are widely available and cheap, the reaction process is simple and easy to control, and the size of the product is related to the reaction temperature.
2mmol hafnium dioxide, 2mmol lithium carbonate and 20mmol magnesium metal powder are added to a 20 ml stainless steel autoclave, sealed and placed in an electric furnace capable of temperature program. The furnace temperature rises from room temperature to 700 ° C within 80 minutes, and then is maintained at 700 ° C for 10 hours after natural cooling to room temperature. The final product in the autoclave includes black deposits and residual gas. The black sediment stuck on the inner surface of the kettle wall was collected and washed with distilled water, dilute hydrochloric acid and anhydrous ethanol several times. The samples obtained after filtration were dried in a vacuum drying oven at 50℃ for 4 hours, and finally collected for characterization.
The powder was analyzed by rigakud/ Max-gamma-A X-ray powder diffraction (xrd) instrument, graphite monochromator, tube pressure and current were 40kv and 40ma respectively, and the scanning speed was 10.0 degrees per minute. Figure 1 shows the X-ray diffraction spectra of the product prepared in Embodiment 1. It can be seen from Figure 1 that in the X-ray diffraction pattern, 2θ has all the diffraction peaks at 10-80°, in which the diffraction intensity is high and the peak shape is sharp. All the diffraction peaks in the figure can be labeled as the cubic phase of hafnium carbide without other impurity peaks. Field emission scanning electron microscopy (fesem,jeoljsm-6300f) was used to observe the morphology and particle size of the products. It can be seen from the field emission scanning electron microscope photo of the product in Figure 2 that the hafnium carbide nanomaterial obtained by the method of the invention is composed of nanoparticles, and the size of the hafnium carbide nanoparticles is 10nm. From the transmission electron microscope photograph of the product (Figure 3), it can also be seen that the hafnium carbide nanomaterial obtained by the method of the invention is made of hafnium carbide nanoparticles with an average size of 10nm. From the thermogravimetric analysis curve of the product (shimadzu-50) Figure 4, it can be seen that the product of hafnium carbide will not be oxidized by air below 300 degrees Celsius, and has good oxidation resistance. When the temperature reaches 600 degrees Celsius, the hafnium carbide is oxidized to hafnium dioxide and carbon. When the temperature exceeds 600 degrees Celsius, the elemental carbon will be oxidized to carbon dioxide, so the phenomenon of mass reduction.
Taking the above ideal embodiments based on the invention as inspiration, through the above explanatory content, the relevant personnel can make various changes and modifications within the scope of not deviating from the technical ideas of the invention.
18
12月
