GO/Ag3PO4复合光催化剂的制备、表征及光催化性能

以石墨粉为原料,采用Hummers氧化法合成氧化石墨烯(GO).然后在超声作用下,将不同含量的Ag₃PO₄沉积在GO上,制备了一系列4% (w,质量分数) GO/Ag₃PO₄、8% GO/Ag₃PO₄、16% GO/Ag₃PO₄和32% GO/Ag₃PO₄复合光催化剂.对所制备的光催化剂运用N₂物理吸附、X射线粉末衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、拉曼光谱、傅里叶变换红外(FT-IR)光谱、紫外-可见漫反射吸收光谱(UV-Vis DRS)等手段进行了表征,并在可见光下考察了GO含量对Ag₃PO₄光催化降解甲基橙(MO)的性能.结果表明, GO能够和Ag₃PO₄实现均匀复合.复合GO提高了催化剂的比表面积,改善了催化剂的吸附性能.复合16% GO使Ag₃PO₄光催化活性提高最显著, 120 min内对MO的降解率达到83%,是纯Ag₃PO₄光催化活性的7.5倍. GO能提高催化剂的比表面积,促进光生电子-空穴(e^-/h⁺)的分离,产生更多活性自由基,从而提高Ag₃PO₄光催化的活性和稳定性.

Preparation and Characterization of GO/Ag3PO4 Composite Photocatalyst and Its Visible Light Photocatalytic Performance

Graphene oxide (GO) was fabricated from graphite powder by Hummers oxidation method and then, under ultrasonic irradiation, a series of GO/Ag₃PO₄ composite photocatalysts (4% (w, mass fraction) GO/Ag₃PO₄, 8% GO/Ag₃PO₄, 16% GO/Ag₃PO₄, 32% GO/Ag₃PO₄) were synthesized by a facile liquid deposition process. The products were characterized by N₂-physical adsorption, powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectra, Fourier transform infrared (FT-IR) spectroscopg, and UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS). The effect of GO content on the photocatalytic activity of Ag₃PO₄ was evaluated by photocatalytic degradation of methyl orange (MO) under visible light irradiation. The results show that GO can be easily dispersed into Ag₃PO₄, producing a well-connected GO/Ag₃PO₄ composite. Coupling of GO largely enhanced the surface area of the catalyst and the adsorption of MO. At the optimal GO content (16%), the degradation rate of MO over GO/Ag₃PO₄ was 83% after 120 min of light irradiation, exhibiting 7.5 times higher activity than that of pure Ag₃PO₄. The increase in photocatalytic activity and stability can be mainly attributed to the coupling of GO, which increased the surface area and suppressed the recombination rate of electron-hole (e^-/h⁺) pairs and generated greater numbers of active free radicals.