Pt/g-C_3N_4的可见光光催化异辛烷脱硫性能及机理

Photocatalytic desulfurization activity and mechanism of Pt/g-C_3N_4 in isooctane under visible light irradiation

采用固相热聚合和浸渍法制备了Pt/g-C_3N_4光催化剂,以300 W氙灯模拟太阳光作为可见光光源,研究了光催化异辛烷脱硫性能及机理。采用XRD,TEM,EDS,UV-Vis,GC-FPD等方法对Pt/g-C_3N_4光催化剂的微结构及脱硫性能进行表征。表征结果显示,Pt只是沉积在g-C_3N_4的表面,可有效富集电子,减少电子和空穴的复合,增加了电子与O_2结合的几率,从而提高了光催化剂Pt/g-C_3N_4的光催化活性。实验结果表明,Pt负载量为0.1%(w)的Pt/g-C_3N_4光催化脱硫效果最好,光催化脱硫率达到76.8%;在整个光催化脱硫过程中O_2和空穴均起到重要的作用,空穴参与了噻吩的氧化。

Pt/g-C3N4 was synthesized by directly heating melamine and impregnation method, then Pt/g-C3N4 was used as photoeatalyst in photocatalytic desulfurization using 300 W xenon lamp as the visible light source. The activity and mechanism of photocatalytic desulfurization was analyzed. Morphology and optical absorption were investigated by XRD, TEM, EDS, UV-Vis and GC- FPD. The results show that Pt is deposited on the surface of g-C3N4. Pt can enrich e, reduce the recombination of e and h^＋, and increase the combination of 02 and e. 0.1%（w）Pt/g-C3N4 possesses the best the photocatalytic desulfurization activity, whose desulfurization ratio reaches 76.8%. Both 02 and h^＋ play an important role in the whole process of photocatalytic desulfurization, and h^＋ is involved in the oxidation of thiophene.