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.
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