论文部分内容阅读
以乙酸锌为原料,无水乙醇为溶剂,二乙醇胺为络合剂,采用溶胶-凝胶法制得ZnO溶胶,并经静置、干燥制得凝胶,随后在氧化气氛及N2保护气氛中分别煅烧得到白色ZnO和黑色ZnO/C材料。采用X射线衍射分析仪(XRD)测定试样物相,用化学元素分析仪测定试样中的碳含量,用扫描电镜(SEM)观察试样的显微形貌、用BET氮吸附容量法测定试样的比表面积,用紫外可见漫反射光谱法测定试样在不同光波长范围的吸收,进而计算出ZnO/C的禁带宽度;用亚甲基蓝(MB)溶液为目标物,测定了试样的光催化降解性能。结果表明,在600℃N2气氛下保温5h制得的ZnO/C中的ZnO为六方纤锌矿结构,呈棒状;ZnO/C复合材料含碳量占总质量的8%;比表面积达到24.5m~2/g;该复合材料在模拟太阳光下照射70min可以使MB溶液的脱色率高达98%以上,而ZnO在相同条件下对MB的降解率只有42%。分析表明,ZnO/C材料光催化效果好的主要原因是由于它在还原气氛下煅烧后的能隙为2.96eV,而白色ZnO的能隙为3.35eV。
Taking zinc acetate as raw material, anhydrous ethanol as solvent, diethanolamine as complexing agent, ZnO sol was prepared by sol-gel method, and after being allowed to stand, dried to obtain a gel, followed by oxidizing atmosphere and N2 protecting atmosphere respectively Calcined to obtain white ZnO and black ZnO / C material. The phase of the sample was determined by X-ray diffraction (XRD), the content of carbon in the sample was determined by chemical elemental analysis, and the microstructure of the sample was observed by scanning electron microscope (SEM). The BET specific nitrogen adsorption capacity The specific surface area of the sample was measured by UV-visible diffuse reflectance spectroscopy to determine the absorption of the sample in different light wavelength range, and then calculate the forbidden band width of ZnO / C; methylene blue (MB) solution as the target, measured the sample Photocatalytic degradation. The results show that the ZnO / ZnO in ZnO / C prepared under the atmosphere of N2 at 600 ℃ for 5h is hexagonal wurtzite with a rod shape; the carbon content of ZnO / C composites is 8% of the total mass; the specific surface area reaches 24.5m ~ 2 / g. The composites irradiated by simulated sunlight for 70min could make the decolorization rate of MB solution more than 98%, while the degradation rate of MB under the same conditions was only 42%. The analysis shows that the main reason for the good photocatalytic activity of ZnO / C is that the energy gap after calcination in the reducing atmosphere is 2.96eV, while that of white ZnO is 3.35eV.