Construction and preparation of novel 2D metal-free few-layer BN modified graphene-like g-C3N4 with enhanced photocatalytic performance.

Novel two-dimensional (2D) metal-free few-layer BN/graphene-like g-C3N4 (2D BN/g-C3N4) composites have been synthesized by a simple hydrothermal method. The construction of a 2D/2D structure between BN and g-C3N4 could shorten the migration distance of charge transfer, and provide a large contact surface. By introducing few-layer BN nanosheets into g-C3N4, the as-prepared 2D BN/g-C3N4 composites exhibited a much enhanced photocatalytic performance than that of pure g-C3N4. The 0.5% 2D BN/g-C3N4 composite possessed the most wonderful ability towards Rhodamine B (RhB) degradation irradiated by visible light, which could achieve a highest degradation efficiency of 98.2% within 120 min. Further studies revealed that modifying g-C3N4 with few-layer BN could not only facilitate the separation and transfer of photo-induced holes and electrons, but also exposed the fact that the (002) facet edges of BN terminated with -OH groups could act as catalytic sites, and thus enhance the photocatalytic activities. Moreover, the successful preparation of 2D BN/g-C3N4 composites may pave the way for fabricating other 2D composites with a layer-by-layer architecture.