固相合成g-C_3N_4及其可见光催化还原水中六价铬

Solid phase synthesis of g-C_3N_4 with performance in visible light-driven photocatalytic reduction of aqueous Cr(VI)

本文以尿素、二聚氰胺和三聚氰胺为原料,通过固相法得到g-C_3N_4粉末。使用射线衍射(XRD)、紫外-可见吸收光谱(UV-vis)、傅里叶红外光谱(FTIR)和透射电镜(TEM)等手段对催化剂的结构和性能进行了表征,并通过可见光催化还原水中六价铬的实验评价g-C_3N_4的光催化性能。实验结果显示:用硝酸室温处理g-C_3N_4粉末的光催化活性增强;反应体系中加入0.3 mmol/L的蔗糖、葡萄糖及草酸(牺牲剂)时,g-C_3N_4催化还原的活性均有提升,其中草酸作为牺牲剂、可见光照射100min时六价铬的还原率从8%提高到52%。

g-C3N4powder was synthesized via the solid phase reaction of urea,poly melamine and melamine compounds as raw materials.The structure and properties of the as-synthesized g-C3N4were characterized by X-ray diffraction(XRD),ultraviolet-vis absorption(UVvis),fourier transform infrared spectroscopy(FTIR)and transmission electron microscopy(TEM),and the photocatalytic properties were tested for the reduction of aqueous Cr(VI)under visible light irradiation.It was found that photocatalytic activity of g-C3N4powder was enhanced treated with nitric acid at room temperature,also the photocatalytic activity of as-synthesized g-C3N4were improved when the sacrificial agent(eg.sucrose,glucose and oxalic acid)were added in the300mL25mg/L aqueous Cr(VI).Furthermore,the photocatalytic reduction rate of Cr(VI)of was52%when oxalic acid as a sacrificial agent under visible light irradiated100min.