Application of a calcined animal bone to synthesis of graphitic carbon nitride composite

Graphitic carbon nitride (g-C₃N₄) is a polymeric organic semiconductor that has been extensively developed for various applications. In this study, composites of g-C₃N₄ and calcined animal bone (CAB) were facilely synthesized by calcining a mixture of urea and CAB at different temperatures. The results revealed that the calcination temperature influenced yield, crystallinity, and band gap of g-C₃N₄. In addition, ultraviolet-visible diffuse reflectance spectroscopy indicated a shift in absorption edge to the high wavelength side in the presence of CAB, implying that CAB promoted thermal condensation of urea. However, thermogravimetric measurements revealed that g-C₃N₄ yield decreased as the calcination temperature increased in the presence of CAB. This is because the amount of g-C₃N₄ was scarce when the mixture was calcined at 823 K. Furthermore, the results of differential thermal analysis indicated that g-C₃N₄ and its intermediates were oxidatively decomposed by CAB at 823 K.