An improved carbothermal process for the synthesis of fine-grained boron carbide microparticles and their photoelectrocatalytic activity

Herein we develop an improved carbothermal process using cellulose as organic carbon resources to synthesize uniform B4C particles in fine-grained size. The improvement of the proposed carbothermal processes lies in two points: (i) we use immiscible hexane/water solvents to obtain high-dispersed boric acid (BA), which promotes the esterification of BA with organic carbon; (ii) the boron oxide/carbon resources are ground sufficiently before high-temperature carbonization. The purpose of these two procedures is to increase the homogeneity of precursors, and their effects on the final crystalline structure and morphology of B4C are studied systematically. The results show that uniform fine-grained B4C in about 4 mu m is successfully fabricated, indicating the homogeneity of precursors can effectively meliorate the B4C powder in a smaller size. The photoelectrochemical and photoeldctrocatalytic performances of the as-prepared fine-gained B4C powder are also investigated. Interestingly, the fine B4C microparticles exhibited a good photoelectrocatalytic hydrogen generation activity in water reduction.