High yield synthesis of novel boron nitride submicro-boxes and their photocatalytic application under visible light irradiation

In this study, hexagonal boron nitride submicro-boxes (BNMB) (0.50-1.4 mm) have been synthesized by using KBH(4), NH(4)F and Zn in a stainless steel autoclave at 450 degrees C. The formation process was studied by XRD, TEM and EDS, and it is considered that the in situ formed KZnF(3) intermediate cubes serve as templates for the formation of BNMB. The as-formed BNMB, with unique structural features, high specific surface area (similar to 86.9 m(2) g(-1)) and good chemical properties, can be applied as a catalyst support for SnO(2). The UV-Vis diffuse reflectance spectrum of SnO(2)/BNMB shows the absorption edge in the visible region (similar to 470 nm), making it suitable for photocatalytic application. The experimental result indicates that the SnO(2)/BNMB exhibited excellent photocatalytic activity on the degradation of methyl orange (MO), which was up to 92% after 30 min of visible-light (lambda > 420 nm) irradiation. The good photocatalytic activity was attributed mainly to its suitable band gap energy, strong adsorption ability for MO, and effective charge separation at the SnO(2)/BNMB photocatalyst interface.