Low-temperature synthesis of nanosized metal borides through reaction of lithium borohydride with metal hydroxides or oxides

• Published in: Journal of alloys and compounds 2015-12, Vol.651, p.666-672
• Main Authors: Pan, Wei Yuan, Bao, Qian Wen, Mao, Yang Jun, Liu, Bin Hong, Li, Zhou Peng
• Format: Article
• Language: English
• Subjects: Borides; Hydroxide; Lithium; Lithium borohydride; Metal boride; Metal hydroxides; Nanostructure; Oxide; Oxides; Synthesis (chemistry); Titanium dioxide; Transition metals
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2015.08.149

In this study, we report a novel and facile synthesis approach of boron-rich transition metal borides such as LaB6 and TiB2 through reaction of lithium borohydride (LiBH4) with corresponding metal hydroxide or oxide at temperatures below 600 °C. A fast endothermic reaction occurred at around 350 °C in the ball milled mixture of 6LiBH4 + La(OH)3 or 12LiBH4 + La2O3, efficiently producing crystalline LaB6 nanoparticles of a size smaller than 100 nm. In comparison, the reaction of LiBH4 with TiO2 proceeded within a wide temperature range from 120 °C to 500 °C, resulting in the formation of nanocrystalline TiB2 of only a few nanometers. This synthesis method proved to be a facile and general route to fabricate nanosized transition metal borides. [Display omitted] •Metal boride synthesis starting with LiBH4 and (hydro)oxides.•A low temperature, facile and general synthesis process was developed.•LaB6 nanoparticles of less than 100 nm were synthesized at 350 °C.•Nanosized TiB2 of a few nanometers was obtained.