木质纤维基碳量子点/介孔TiO2复合体系的构建及光催化性能的研究

Preparation of Lignocellulose Based Carbon Quantum Dots/Mesoporous TiO2 Composite and Its Photocatalytic Performance

关键词:  介孔TiO₂  碳量子点  玉米芯残渣  木素  光催化

Key Words:mesoporous TiO₂  carbon quantum dots  corncob residues  lignin  photocatalysis

摘要:本研究以氮掺杂酶解玉米芯残渣碳量子点（E-N-CQDs）和介孔TiO₂进行复合，构建了介孔TiO₂/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TiO₂具有较大的比表面积，孔径8~32 nm；与介孔TiO₂相比，光照300 min时，介孔TiO₂/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TiO₂的光催化降解能力，提高了对可见光的利用率。

Abstract:In this study， a composite photocatalyst system （mesoporous TiO₂/E-N-CQDs） was constructed by using nitrogen-doped CQDs （E-N-CQDs） from enzymatically hydrolyzed corncob residues and mesoporous TiO₂. The resultant mesoporous TiO₂/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 E-N-CQDs enhanced its fluorescence. The prepared mesoporous TiO₂ 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 TiO₂/E-N-CQDs achieved 89% when irradiation time was 300 mins， increased by 59% compared with using mesoporous TiO₂， suggesting that the addition of E-N-CQDs significantly enhanced the photocatalytic ability of mesoporous TiO₂， improved the utilization efficiency of the visible light.