【摘要】 以纳米晶纤维素（NCC）为形貌诱导模板,醋酸锌（Zn（CH₃COO）₂·2H₂O）为Zn源,采用原位聚合法制备NCC/ZnO纳米杂化物,再经550℃高温碳化,得到生物质炭/ZnO复合材料。采用TEM、XRD、BET、UV-Vis测试研究生物质炭与ZnO固体质量比（0.03∶1、0.17∶1、0.67∶1）对生物质炭/ZnO复合材料形貌、晶体结构、孔结构及光吸收性能的影响。并进一步以亚甲基蓝（MB）为模型污染物,研究生物质炭/ZnO复合材料的吸附-光催化性能,阐明其吸附-光催化机制。结果表明,经550℃高温碳化后,NCC转化为具有石墨微晶结构的生物质炭,其骨架结构得以保留,纳米ZnO均匀负载在生物质炭表面,形成生物质炭/ZnO复合材料。与纯纳米ZnO相比,生物质炭/ZnO复合材料比表面积显著提高,具备优异的吸附性能,同时,NCC转化得到的生物质炭有效提高了ZnO的光生电子-空穴对的分离率。生物质炭/ZnO复合材料通过吸附-光催化协同效应去除水体中的MB,去除率显著增加。当生物质炭与ZnO的固体质量比为0.17∶1时,生物质炭/ZnO复合材料的平均孔径为188.99nm,比表面积为33.51m²/g,在室温条件下,避光吸附30min后,再使用500W紫外灯照射20min,即对MB降解率达到99.8%。更多还原

【Abstract】 The nano crystalline cellulose（NCC）/ZnO nano hybrids were prepared with a procedure of in-situ polymerization using NCC as a morphological-inducing template,and Zn acetate（Zn（CH₃COO）₂·2H₂O）as a Zn source,respectively.The NCC/ZnO nano hybrids were then carbonized at 550^oC to obtain biochar/ZnO composites.The morphology,crystal structure,pore texture and light absorption performance of biochar/ZnO composites influenced by a mass ratio of biochar to ZnO（0.03∶1,0.17∶1,0.67∶1）were characterized by TEM,XRD,BET and UV-Vis spectroscopy.The adsorption-photocatalysis performance of biochar/ZnO composites was investigated through removing methylene blue（MB）under UV light irradiation,and the mechanism of biochar/ZnO composites was further studied.The results indicate that the NCC transforms to biochar with graphite crystallite and skeleton structure after a carbonization process at 550℃.The nano ZnO particles are uniformly deposited on the surface of biochar,and then the biochar/ZnO composites are obtained.The obtained biochar/ZnO composites exhibit higher surface area and better absorbability compared with the neat nano ZnO.And the biochar improves the separation of photogenerated electrons and holes of ZnO.The biochar/ZnO composites remove MB with a synergistic effect of adsorption and photocatalysis.In particular,the biochar/ZnO composite has an average pore diameter of 188.99nm,and a specific surface area of 33.51m²/g respectively at the mass ratio of 0.17∶1（biochar to ZnO）.Consequently,the biochar/ZnO composite has an optimum degradation efficiency to MB,corresponding to 99.8%degradation rate of MB after the absorption for 30min in dark condition and continuous irradiation for 20min under 500W UV light at room temperature.更多还原