Spectral analysis of wheat straw soda lignin with photocatalytic degradation

作者：Ren Zh · 发表于：Zhongnan Linye Keji Daxue xuebao · 年份：2014 · 被引用次数：1 · 研究领域：Lignin and Wood Chemistry

The photocatalytic degradation of lignin obtained from the black liquor of wheat straw soda-AQ digestion proceeded in a self-made reactor. The three basic factors including light, oxygen and photosensitize were combined with different combining types and the catalytic degradation pathway of alkali lignin was studied. The mechanism of photocatalytic process was studied via the UVvis and FTIR analysis. And also the structure changes in lignin and the attribution of each pathway were discussed with respect to photocatalytic degradation. The results show that little changes occurred directly in lignin structure when lignin was exposed to the UV light; the benzene rings in lignin can be open with the help of light and oxygen, and also the ether bonds connected with the lignin units were cracked; the addition of photosensitizer Rose Bengal can do favor to produce singlet oxygen which can accelerate the degradation of lignin at some extent. It indicated that free radicals and singlet oxygen made great contribution to the photocatalytic degradation of lignin. Triplet photosensitizers can not directly react with ligninions; but under the condition of oxygen access, the reaction of triplet photosensitizers and molecular oxygen generated singlet oxygen, which accelerated the lignin's photocatalytic degradation