NCDs/TiO2复合材料的制备及其在太阳光下催化制氢的应用

采用溶剂热法, 以乙腈为溶剂和葡萄糖为原料制备了粒径约4 nm的氮掺杂碳量子点NCDs。当激发波长从330 nm增加到470 nm, NCDs水溶液发射光谱出现红移。随后, 将一定配比的NCDs、TiO₂及5 mL超纯水超声混合60 min, 并在80℃烘箱内陈化24 h, NCDs纳米颗粒成功地复合到TiO₂(TiO₂)表面。该方法有效地拓宽了TiO₂吸收光谱的范围, 并且减少了光生电子和空穴对, 从而增强了TiO₂的光催化制氢性能。实验结果表明: 投料比为m(NCDs):m(TiO₂)=15:85时, 以甲醇为牺牲剂的反应体系光催化制氢效果最好, 该复合材料具有一定的稳定性, 循环三次使用后仍然有一定的光催化制氢性能。

Nitrogen Doped Carbon Quantum Dots/Titanium Dioxide Composites for Hydrogen Evolution under Sunlight

Using acetonitrile as the solvent and glucose as the raw material, nitrogen doped carbon quantum dots (NCDs) were prepared by the solvothermal method. The size of NCDs is around 4 nm. The emission spectrum of NCDs showed red shift when the excitation wavelength of quantum dots increased from 330 nm to 470 nm. Titanium dioxide was coated by NCDs by mixing a certain proportion of NCDs, TiO₂ and ultrapure water through 60 min ultrasonic and aging under 80℃ for 24 h. NCDs/titanium dioxide composites show good photocatalyst performance as compared with pure NCDs and pure titanium dioxide, because the NCDs can expand the absorption spectrum and reduce the photogenerated electrons and holes. The NCDs/TiO₂ composites at the raw ratio of m(NCDs):m(TiO₂)=15:85 show the best hydrogen evolution performance, using methanol as the sacrificial agent. The composite material displays good stability and certain photocatalytic performance after three cycles.