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

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-C_(3)N_(4));采用紫外-可见漫反射光谱(DRS)和荧光光谱(PL)分析Glucose-g-C_(3)N_(4)的光吸收性能和电子-空穴对分离能力;并利用Glucose-g-C_(3)N_(4)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-C_(3)N_(4)),Glucose-g-C_(3)N_(4)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-C_(3)N_(4)投加量0.5 g/L、4-CP质量浓度10 mg/L的条件下,Glucose-g-C_(3)N_(4)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-C_(3)N_(4)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-C_(3)N_(4)的光催化活性和对PDS的活化能力。

C-doped graphite phase carbon nitride catalyst(Glucose-g-C_(3)N_(4))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-C_(3)N_(4) were analyzed by UVvis diffuse reflectance spectroscopy(DRS)and fluorescence spectroscopy(PL).Glucose-g-C_(3)N_(4) 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-C_(3)N_(4) 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-C_(3)N_(4) dosage of 0.5 g/L,and 4-CP concentration of 10 mg/L,Glucose-g-C_(3)N_(4) 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-C_(3)N_(4) 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.