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

Abstract

In this study, hexagonal boron nitride submicro-boxes (BNMB) (0.50–1.4 μm) have been synthesized by using KBH₄, NH₄F and Zn in a stainless steel autoclave at 450 °C. The formation process was studied by XRD, TEM and EDS, and it is considered that the in situ formed KZnF₃ intermediate cubes serve as templates for the formation of BNMB. The as-formed BNMB, with unique structural features, high specific surface area (∼86.9 m² g⁻¹) and good chemical properties, can be applied as a catalyst support for SnO₂. The UV-Vis diffuse reflectance spectrum of SnO₂/BNMB shows the absorption edge in the visible region (∼470 nm), making it suitable for photocatalytic application. The experimental result indicates that the SnO₂/BNMB exhibited excellent photocatalytic activity on the degradation of methyl orange (MO), which was up to 92% after 30 min of visible-light (λ > 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 SnO₂/BNMB photocatalyst interface.