Graphitic carbon nitride (g-C₃N₄) is a fascinating nonmetallic photocatalyst for the removal of environmental pollutants. The fumed silica/g-C₃N₄ (gCN-FS) composite photocatalysts were successfully fabricated by a combination of solvent volatilization and post-annealing methods. The introduction of SiO₂ not only widens the absorption range of visible light, but also enhances the specific surface area of g-C₃N₄. The gCN-FS-3 composite has a BET surface area of 129.89 m²/g, which is ~3.3 times as much as that of g-C₃N₄ (39.54 m²/g). The gCN-FS composites have markedly improved rhodamine B (RhB) photodegradation activity in comparison to pure g-C₃N₄, bulk g-C₃N₄ and P25 under 557 nm yellow-green light emitting diode light irradiation. The gCN-FS-3 has the highest RhB photodegradation rate, which is ~9.67-, 11.81-folds as compared to bare g-C₃N₄ and bulk g-C₃N₄, respectively. The coupling effect between the increase in specific surface areas and the inhibition effect of SiO₂ on photogenerated electron/hole pairs recombination is responsible for the enhanced visible light photocatalytic activity of gCN-FS composite. Superoxide and holes are responsible for the RhB photocatalytic degradation. Furthermore, no apparent loss of photocatalytic activity over five cycles is observed, which indicates that the gCN-FS composites have considerable stability and reusability in the photodegradation process. The gCN-FS composites show great promise in visible light driven photocatalysis for environmental applications.

中文翻译：

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新型气相二氧化硅/g-C3N4复合材料在可见光发光二极管光照射下高效去除罗丹明B

石墨氮化碳 (gC ₃ N ₄ ) 是一种用于去除环境污染物的迷人的非金属光催化剂。通过溶剂挥发和后退火相结合的方法成功制备了气相二氧化硅/gC ₃ N ₄ (gCN-FS)复合光催化剂。SiO ₂的引入不仅拓宽了可见光的吸收范围，而且提高了gC ₃ N ₄的比表面积。的GCN-FS-3复合材料具有129.89米的BET表面积² / g，这是〜3.3倍，作为GC的₃ Ñ ₄（39.54米²/G）。与纯gC ₃ N ₄、块状gC ₃ N ₄和P25相比，gCN-FS复合材料在557 nm黄绿色发光二极管光照射下具有显着提高的罗丹明B（RhB）光降解活性。gCN-FS-3 具有最高的 RhB 光降解率，分别是裸 gC ₃ N ₄和块状 gC ₃ N _{4 的}9.67 倍和 11.81 倍。比表面积增加与SiO ₂抑制作用的耦合效应光生电子/空穴对复合是gCN-FS复合材料可见光光催化活性增强的原因。超氧化物和空穴负责 RhB 光催化降解。此外，在五个循环中没有观察到光催化活性的明显损失，这表明 gCN-FS 复合材料在光降解过程中具有相当大的稳定性和可重复使用性。gCN-FS 复合材料在可见光驱动的光催化环境应用中显示出巨大的前景。