Pt2+/Pt0掺杂g-C3N4光催化降解环丙沙星和偶氮染料

以三聚氰胺和氯铂酸(H2PtCl6·6H2O)为原材料,采用简单一步煅烧法制备了不同含量的Pt^2+/Pt^0掺杂石墨相氮化碳(Pt^2+/Pt^0-CN)。运用扫描电镜、透射电子显微镜、X射线光电子能谱、X射线粉末衍射、N2物理吸附-脱附、紫外-可见漫反射光谱和光电流测试等技术对制备的样品的形貌、化学组成、晶体结构、比表面积和光电性能等物理化学性质进行了表征。由XPS可知Pt粒子以二价Pt和零价Pt掺杂在催化剂的表面和内部,其中Pt^0与Pt^2+的比约为1∶7.26。与g-C3N4相比,Pt^2+/Pt^0-CN表现出高效的光催化降解活性。当Pt^2+/Pt^0理论负载质量分数为0.02%时,对环丙沙星、罗丹明B、酸性橙Ⅱ、甲基橙和亚甲基蓝的降解效率分别提升了43%、64%、39%、42%和52%。Pt^2+/Pt0掺杂使催化剂的比表面积大幅度增加,同时增强光催化剂对光的吸收能力,并抑制光生电子(e^-)和空穴(h^+)的复合。

Photocatalytic Degradation of Ciprofloxacin and Azo Dyes by Pt2+/Pt0 Doped g-C3N4

Using melamine and chloroplatinic acid(H2PtCl6·6H2O)as raw materials,graphite phase carbon nitride doped with different contents of Pt^2+/Pt^0(Pt^2+/Pt^0-CN)was prepared by a simple one-step calcination method.Their morphologies,crystal structure,chemical compositions,surface area,optical and electrical physicochemical properties were characterized by scan microscopy,transmission electron microscopy,X ray powder diffraction,X ray photoelectron spectroscopy,N2 physical adsorption-desorption,UV-Visible diffuse reflectance spectra and photocurrent measurement.From the XPS analysis,the ratio of Pt^0 and Pt^2+ was around 1∶7.26.Platinum particles were doped into the surface and body of the g-C3N4.Compared with g-C3N4,Pt^2+/Pt^0-CN composites showed much higher photocatalytic degradation activity than that of g-C3N4.With theory loading mass fraction of Pt^2+/Pt^0(0.02%),the degradation rates of ciprofloxacin,rhodamine B,acid orangeⅡ,methyl orange and methylene blue were increased 43%,64%,39%,42%and 52%,respectively.The doping of Pt^2+/Pt^0 into g-C3N4 can largely boost the surface area.At the same time,the light absorption of Pt^2+/Pt^0-CN composites was enhanced and the recombination of photogernerated holes(h^+)and electrons(e^-)was restrained.