无模板法制备多孔g-C_3N_4及其可见光催化性能

Template-free Preparation of Porous g-C_3N_4 for Visible-light Catalysis

采用超声工艺与硫酸水热改性相结合,在无模板剂条件下制备出多孔g-C3N4材料。通过粒径分析、X射线衍射仪、扫描电镜、比表面积测试和紫外-可见漫反射光谱等表征手段,系统研究了超声时间、水热条件等对其粒径大小、晶体结构、表面形貌、孔结构以及光吸收性能的影响,并考察了超声处理和水热改性g-C3N4对甲基橙和罗丹明B的可见光催化行为。结果表明:超声处理与水热改性工艺结合有利于提高g-C3N4材料多孔性,增强其对污染物的吸附能力,并在一定程度上提高光生载流子的分离-转移效率,从而提高了g-C3N4的可见光催化活性。

A novel and facile template-free method was presented to fabricate a porous g-C3N4(graphite-like carbon nitaide) by combining ultrasonic treatment with hydrothermal modification in the presence of sulfuric acid. Particle size analysis, X-ray diffraction(XRD), scanning electron microscopy(SEM), Brunauer-Emmett-Teller(BET), and UV-vis diffuse reflectance spectra(DRS) were adopted to analyze its structure, morphology and properties. And the photocatalytic activities of the as-prepared samples were also evaluated by decomposing methyl orange(MO) and Rhodamine B(Rh B) in aqueous solution under visible light illumination. The results show that combining ultrasonic treatment with hydrothermal modification is favorable to improve the porosity of g-C3N4, which can increase the ability to absorb pollutants and inhibit the recombination of photo-generated carriers, thereby enhancing the visible-light photocatalytic property.