Hydroxyapatite-based catalysis in environmental decontamination

Until now, many publications have concerned on the synthesis of hydroxyapatite (HAP) and its application in heterogeneous catalytic process. The HAP supported catalysts performed favorable properties in catalytic decontamination. This review presented a comprehensive discussion on the synthesis, characterization and the application of HAP and HAP derived catalysts in decontamination. HAP could be prepared through thermal treatment of animal bone, solid-state reaction, wet precipitation, sol-gel, hydro/solvothermal, emulsion methods, while the impregnation, ion exchange, hydrothermal methods were conducted on synthesis of HAP derived catalysts. The properties of the HAP and its derived catalysts were characterized through XRD, SEM, TEM and CO2/NH3-TPD ananlysis. Especially, the properties corresponding to the synthesized methods are described. The activity of the HAP derived catalysts in eliminating pollutants such as organics, nitrogen oxides and carbon oxides were reviewed. Effect of the active metal and HAP property on the catalytic activity on decontamination was discussed. Thus, a bridge among the synthesis and characterization of HAP derived catalysts with their applications in environmental decontamination is constructed, which presents a prospective view in the development of HAP derived catalysts and their applications in future.