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 B 4 C 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 B 4 C are studied systematically. The results show that uniform fine-grained B 4 C in about 4   µm is successfully fabricated, indicating the homogeneity of precursors can effectively meliorate the B 4 C powder in a smaller size. The photoelectrochemical and photoelectrocatalytic performances of the as-prepared fine-gained B 4 C powder are also investigated. Interestingly, the fine B 4 C microparticles exhibited a good photoelectrocatalytic hydrogen generation activity in water reduction.