Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China.
College of Mechanics and Materials, Hohai University, Nanjing, 210098, China.
Environ Sci Pollut Res Int. 2019 May;26(15):15710-15723. doi: 10.1007/s11356-019-04800-3. Epub 2019 Apr 5.
In order to overcome photocatalytic technology application limitations in water due to weak light intensity, it is crucial to synthesize photocatalysts that respond to weak light. In this study, porous and oxygen-doped carbon nitride (CN-MC) was synthesized via supramolecular preassembly technology using melamine and cyanuric chloride. The carbon nitride catalyst produced via this technology has a relatively high surface area (63.2 m g), irregular pores, and oxygen doping characteristics, which enhance the light capture capacity, increase the number of reactive sites, and accelerate electron-hole separation efficiency. Thus, the CN-MC exhibited excellent photocatalytic activity during the degradation of organic pollutants Rhodamine B (RhB, 95% removal within 6 h) and tetracycline hydrochloride (TC-HCl, 70% removal within 6 h) under low-intensity light (the light intensity = 0.8~1.8 mW cm with a wavelength range of 300-700 nm). Mechanistic analysis showed that ·O and ·OH were the dominant active free radicals during RhB and TC-HCl photocatalytic degradation over CN-MC. The proposed synthesis strategy effectively improves the photocatalytic activity of graphite carbon nitride under weak light by producing a porous morphology and oxygen atom doping.
为了克服由于光强度弱而导致的光催化技术在水中应用的局限性，合成对弱光有响应的光催化剂至关重要。在本研究中，通过超分子预组装技术，使用三聚氰胺和三聚氰氯合成了多孔和氧掺杂的氮化碳（CN-MC）。通过该技术制备的氮化碳催化剂具有相对较高的比表面积（63.2 m g）、不规则的孔和氧掺杂特性，这增强了光捕获能力、增加了反应位点的数量，并加速了电子-空穴分离效率。因此，CN-MC 在低强度光（光强= 0.8~1.8 mW cm，波长范围为 300-700 nm）下对有机污染物罗丹明 B（RhB，6 h 内去除 95%）和盐酸四环素（TC-HCl，6 h 内去除 70%）的降解表现出优异的光催化活性。机理分析表明，在 CN-MC 上进行 RhB 和 TC-HCl 光催化降解过程中，·O 和·OH 是主要的活性自由基。所提出的合成策略通过产生多孔形态和氧原子掺杂，有效地提高了石墨相氮化碳在弱光下的光催化活性。
