Using purified kaolinite as carrier and dicyandiamide as g-C3N4 precursor, a novel visible light responding g-C3N4/kaolinite composite photocatalytic material was prepared through chemical impregnation combined with thermal polymerization method.The crystalline phase, pore structure, interface and optical properties of the obtained composites were characterized by X-ray diffraction (XRD), N2 adsorption-desorption analysis (BET), field emission scanning electron microscope (FESEM) and UV-visible diffused reflectance spectroscopy (UV-Vis), respectively.Using rhodamine B (RhB) as the target pollutant, the visible-light photocatalytic activity of different photocatalyst was investigated.It indicated that when the mass ratio of kaolinite and dicyandiamide is 2∶4, the as-synthesized CN/KA-4 sample (g-C3N4 content 38.82%) significantly exhibited better photocatalytic activity under visible-light irradiation, whose reaction constant rate is almost 4.18 times that of the pure g-C3N4.The g-C3N4 nanosheets were firmly attached on the surface of kaolinite, which could effectively inhibit the recombination of photogenerated carriers and further improve the adsorption capacity and photoactivity of g-C3N4 photocatalyst.%以高岭土为载体、双氰胺为g-C3N4前驱体,采用液相浸渍联合热聚合工艺制备出一种可见光响应的高岭土基复合光催化材料.采用X射线衍射(XRD)、静态氮吸附仪(BET)、场发射扫描电镜(FESEM)、紫外-可见吸收光谱(UV-Vis)等手段对复合材料的晶相、孔结构、界面特性和光学性能进行了表征,并以罗丹明B作为目标污染物考察了不同催化剂的可见光光催化活性.结果表明,当高岭土和双氰胺的质量配比为2∶4,即g-C3N4的实际负载量为38.82%时,所制备的g-C3N4/高岭土复合材料光催化性较优,其光催化速率是纯g-C3N4的4.18倍;高岭石与g-C3N4紧密结合,该复合结构能够有效地抑制光生载流子的复合,改善纯g-C3N4材料的吸附性能与光催化活性.
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