DUAN Feiyang (1995—), male, Master candidate. E-mail: 502399068@qq.com
A series of graphitic carbon nitride (g-C3N4) nanosheets with controllable thicknesses were prepared by a thermal polymerization method with different ratios of precursor melamine and urea. The nanosheets were characterized by X-ray diffraction, scanning electron microscopy, atomic force microscopy, specific surface area measurement, ultraviolet-visible spectroscopy and photoluminescence, respectively, which were used for the photocatalytic degradation of Rhodamine B (RhB). The results show that g-C3N4 is the thinnest (1∶8-CN) with the thickness of 3.5 nm when the ratio of melamine to urea is 1∶8. Its specific surface area is 6 times greater than that of g-C3N4 prepared using only melamine (assigned as M-CN). The photoelectric analysis indicates that 1∶8-CN has a higher separation efficiency of photogenerated carriers. Under the visible-light, the photocatalytic degradation rate of RhB by 1∶8-CN can reach 96.2%, which is 1.9 times greater than that of M-CN. Besides, the photocatalytic degradation mechanism of 1∶8-CN toward RhB is since the electrons generated by the separation of photogenerated electron-hole pairs combine with O2 to generate·O2-, and then·O2- oxidizes RhB into CO2 and H2O, and the holes do hardly participate in the reaction.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |