碳掺杂氮化碳光催化活化过硫酸盐处理AOX的研究

Study on the Treatment of AOX by Carbon Doped Carbon Nitride for Photocatalytic Activation of Persulfate

关键词:  过硫酸盐  石墨相氮化碳  4-氯苯酚  废水处理

Key Words:persulfate  graphitic carbon nitride  4-chlorophenol  wastewater treatment

摘要:本研究采用葡萄糖和三聚氰胺为原料，通过一步共热解法成功制备了碳掺杂石墨相氮化碳（Glucose-g-C₃N₄）；采用紫外-可见漫反射光谱（DRS）和荧光光谱（PL）分析Glucose-g-C₃N₄的光吸收性能和电子-空穴对分离能力；并利用Glucose-g-C₃N₄光催化处理可吸附有机卤化物（AOX）的模拟物4-氯苯酚（4-CP）。结果表明，相较于石墨相氮化碳（g-C₃N₄），Glucose-g-C₃N₄的可见光吸收性能提高和电子-空穴对复合率降低；在模拟太阳光照射下反应120 min、过硫酸盐（PDS）用量0.5 mmol/L、Glucose-g-C₃N₄投加量0.5 g/L、4-CP质量浓度10 mg/L的条件下，Glucose-g-C₃N₄表现出最佳的光催化活性，4-CP的降解率可达87.2%，总有机碳（TOC）的去除率达86.2%。Glucose-g-C₃N₄的光催化活性增强是由于掺杂引入的C原子扩宽了其光吸收范围，减小了带隙并提高电子转移速率，从而提高了Glucose-g-C₃N₄的光催化活性和对PDS的活化能力。

Abstract:C-doped graphite phase carbon nitride catalyst （Glucose-g-C₃N₄） was prepared by one-step co-pyrolysis with glucose and melamine as raw materials. The light absorption properties and electron-hole pair separation ability of Glucose-g-C₃N₄ were analyzed by UV-vis diffuse reflectance spectroscopy （DRS） and fluorescence spectroscopy （PL）. Glucose-g-C₃N₄ was used for the photocatalytic treatment of 4-chlorophenol （4-CP） that was a model of Adsorbable Organic Halide’s analog （AOX）. The results showed that the visible light absorption performance of Glucose-g-C₃N₄ was enhanced and the electron-hole pair complexation rate was reduced. After reaction for 120 min under simulated sunlight irradiation， with persulfate （PDS） dosage of 0.5 mmol/L， Glucose-g-C₃N₄ dosage of 0.5 g/L， and 4-CP concentration of 10 mg/L， Glucose-g-C₃N₄ showed the best photocatalytic activity， and the degradation rate of 4-CP could reach 87.2% and the removal rate of total organic carbon （TOC） reached 86.2%. The photocatalytic activity of Glucose-g-C₃N₄ was enhanced because the doping of C atom broadened the light absorption range，and reduced the band gap， increased the electron transfer rate， promoting the activation of PDS.