The Study Of Preparation Of Boron Nitride With High Specific Surface Area

It is believed that, as a new kind of high specific surface area ceramic materials, boronnitride (BN) with high surface area has wide application prospect and huge market value oncatalytic properties, adsorption properties, hydrogen storage properties and many otherproperties. But the current stage synthetic technology of BN is usually accompanied complexexperimental procedure, or a high synthesis temperature. Traditional method is not only a wasteof resources, but also along with the low work efficiency, in this case the industrial productionhas been greatly restricted. This paper offers the design of synthesizing BN with high specificsurface area according to two approaches. The first way is combining both hard templatemethod and polymer network method. The second way is combining hard template method,activation and polymer network method. In this article, the synthesis process of BN is easy, andthe raw material source that we used is simple, inexpensive and non-toxic. Synthesismechanism, phase composition, microstructure and adsorption properties are studied in thispaper.For the method combining hard template method and polymer network method, this paperstudied the effect of carbonization temperature and sucrose content on the phase composition,microstructure and adsorption properties of the final product. By studying the synthesismechanism, we determined the best synthesis technology. BN are characterized by BET, SEMand XRD. The experiments show that sucrose template favor the formation of BN, and theoptimum carbonization temperature is220℃, the optimum sucrose content is17.45wt%. By theoptimum synthesis conditions, the BN with high surface area belongs to the mesopore and micropore materials, and the morphology is granular, the specific surface area of BN in N2is342.8803m2/g，the pore volume of BN is0.389983cm3/g, average pore diameter is4.54949nm,at this point it shows the best adsorption properties.For the method combining hard template method, activation and polymer network method,this paper studied the effect of activators (KOH/K2CO3), nitriding temperature and boronsucrose content on the phase composition, microstructure and adsorption properties of the finalproduct. By studying the synthesis mechanism, we determined the best synthesis technology.BN are characterized by BET, SEM and XRD. The experiments show that activators favor theformation of BN, and the KOH is better than the K2CO3, and the optimum activating agent ofKOH is9.5wt%, during the boron source content, the best molar ratio of borax to boric acid is0:1, the optimum nitriding temperature is775℃, by the optimum synthesis conditions, the BNwith high surface area belongs to the mesopore and micropore materials, and the morphology isgranular, the specific surface area of BN in N2is405.0725m2/g，the pore volume of BN is0.487373cm3/g, average pore diameter is4.81269nm, at this point it shows the best adsorptionproperties.Now, BN prepared by utilizing the principle of combining both hard template method andactivation have not been reported yet, this study has the innovation and advancement. And theresults in this paper will promote development of high surface area BN in the field of catalyticproperties, adsorption properties, hydrogen storage properties and many other related fields.