以六次甲基四胺(C6H12N4)为氮源,玉米秸秆为模板,采用溶胶-凝胶法制备 N 掺杂 BiVO4(CS-BiVO4-xN),并采用 X 射线衍射(XRD)、X 射线光电子能谱(XPS)、扫描电子显微镜(SEM)、傅里叶红外光谱(FT-IR)、紫外-可见漫反射光谱(UV-Vis)等表征手段对样品进行表征和分析。在可见光照射下,通过光催化降解甲基橙溶液评价 N掺杂对BiVO4光催化剂活性的影响。结果表明： N掺杂没有改变BiVO4的晶型；掺杂的N取代BiVO4中部分O,以-N-V-O形式存在,产生杂质能级, N掺杂导致BiVO4表面氧空位增加,二者协调作用致使禁带宽度变窄,光吸收带边发生红移,提高了其活性。以玉米秸秆为模板制备的蜂窝状BiVO4,颗粒分散好,晶体粒径小,有效提高了BiVO4初始吸附能力,促进了光催化活性；可见光光照50 min 时, CS-BiVO4-12N 样品对甲基橙的脱色率达80.9%,较CS-BiVO4(25.56%)和BiVO4-12N(28.34%)有明显提高。
N-doped BiVO4 photocatalysts (CS-BiVO4-xN) were successfully prepared by Sol-Gel method taking the corn stem as template and C6H12N4 as N source. The samples were characterized with X-ray diffraction (XRD), X-ray photoelectron spectroscope (XPS), scanning electron microscope (SEM), Fourier infrared spectrum (FTIR), and UV-Vis absorption spectroscope (UV-Vis). The photocatalytic activity were investigated by degradation of methyl oran ge (MO) under visible-light irradiation. The results showed that N doping did not change the crystallinity of the BiVO4. The doped N replaced some of O atoms in BiVO4 and formed the-N-V-O band. The synergetic effect of impurity en-ergy levels and oxygen vacancies led to narrower band-gap and red-shift of optical absorption band. Furthermore, the N doped BiVO4 with honeycomb like structure and smaller crystal sizes was prepared by using corn stem as template, which is beneficial to higher initial MO absorption and better photocatalytic activity. The degradation rate of MO un-der visible light illumination for 50 min is 80.9%in presence of CS-BiVO4-12N, which is much higher than those in presence of CS-BiVO4 (25.56%) and BiVO4-12N (28.34%).
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