【摘要】 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。更多还原

【Abstract】 ZnO/C composite material was synthesized by a two-step process.ZnO gel was prepared first with zinc acetate,anhydrous ethanol,and diethanolamine used as raw materials,solvent,and complexing agent,respectively.Then ZnO gel was calcinated in N2 atmosphere.The photocatalytic activity was studied using methylene blue as the degradation object.The microstructure and band gap of ZnO/C composite materials were investigated by XRD,SEM,BET and UV-Vis DRS analysis.The material showed good photocatalytic activity,which can degrade 98% MB at 70 min under the simulated sunlight irradiation,while ZnO prepared with the same method can only degrade 42% MB under the same condition.ZnO was six-party wurtzite structure and liked a stick in ZnO/C composite materials.The carbon content of ZnO/C was 8%.The specific surface area was 24.5m~2/g.The energy gap of ZnO/C was 2.96 eV,while the energy gap of ZnO/C was 3.36 eV.Therefore,under simulated sunlight,the light energy utilization efficiency of ZnO/C samples was higher,thus showing better photocatalytic degradation activity.Analysis showed that ZnO/C composite photocatalytic effect good main reason because it is under the reducing atmosphere calcine.更多还原