木质纤维基碳量子点/介孔TiO_(2)复合体系的构建及光催化性能的研究

Preparation of Lignocellulose Based Carbon Quantum Dots/Mesoporous TiO_(2) Composite and Its Photocatalytic Performance

本研究以氮掺杂酶解玉米芯残渣碳量子点(E-N-CQDs)和介孔TiO_(2)进行复合,构建了介孔TiO_(2)/E-N-CQDs复合光催化剂体系,对其进行了分析表征,并探讨了其对水相中亚甲基蓝(MB)的降解能力。结果表明,E-N-CQDs具有良好的荧光性能,且其表面羧基、氨基等发色基团和助色基团增强了其荧光特性;介孔TiO_(2)具有较大的比表面积,孔径8-32 nm;与介孔TiO_(2)相比,光照300 min时,介孔TiO_(2)/E-N-CQDs对MB的降解率达到89%,提高了59%。由此可见,碳量子点的加入可显著提高介孔TiO_(2)的光催化降解能力,提高了对可见光的利用率。

In this study,a composite photocatalyst system(mesoporous TiO_(2)/E-N-CQDs)was constructed by using nitrogen-doped CQDs(EN-CQDs)from enzymatically hydrolyzed corncob residues and mesoporous TiO_(2). The resultant mesoporous TiO_(2)/E-N-CQDs was characterized and explored to use for the photocatalytic degradation of methylene blue(MB)solution. The results showed that E-N-CQDs exhibited good fluorescence properties,and the chromophoric and auxochromic groups such as carboxyl groups and amino groups on the surface of EN-CQDs enhanced its fluorescence. The prepared mesoporous TiO_(2) had a large specific surface area with a pore size distribution in the range of 8-32 nm. The photocatalytic degradation ratio of MB solution using mesoporous TiO_(2)/E-N-CQDs achieved 89% when irradiation time was300 mins,increased by 59% compared with using mesoporous TiO_(2),suggesting that the addition of E-N-CQDs significantly enhanced the photocatalytic ability of mesoporous TiO_(2),improved the utilization efficiency of the visible light.