Hydroxyapatites synthesized by different approaches for efficient catalytic decomposition of volatile organic compound

抄録

Hydroxyapatite (HAP), as one of the most well-known functional ceramic materials, has attract much attention due to its excellent biocompatibility, ion-exchange ability and adsorption property. By taking advantages of the thermally induced active radicals and unique basic/acidic sites exist on surface of HAP, we’ve succeeded in observing complete decomposition of volatile organic compound (VOC) on HAP which makes it became the most promising noble-metal-free catalyst for VOC controlling and environmental cleaning. In present work, four types of HAPs with altered particle size, morphology, crystallinity and chemical structures were synthesized by utilizing different calcium and phosphorus precursors and altered approaches. With detailed characterizations of obtained HAPs via scanning electron microscopy, powder X-ray diffraction, Fourier-transform infrared microscopy, surface acidity/basicity analysis through NH₃/CO₂ adsorption, the influence of precursors and approaches during synthesis stage on later catalytic activity of HAPs for oxidative decomposition of ethyl acetate is systemically investigated in advance. It was found that the chemical structure tailored during synthesis stage plays an important role in deciding the surface basicity/acidity in obtained HAPs. The resultant HAP with harvested surface basic sites shows better catalytic activity in conversing ethyl acetate into CO₂/CO, while HAP with larger number of acidic sites promotes the generation of organic product of ethylene. The contents in this work provide principal information for design and development of functional ceramic material.