Zr掺杂g-C3N4光催化降解有机污染物

Zr-doped g-C3N4 photocatalytic degradation of organic pollutants

摘要:

以盐酸胍为前驱体，硝酸锆为锆源，通过热聚合法制备了Zr掺杂的Zr/g-C3N4光催化剂。运用XRD、SEM、UV-Vis DRS、PL、XPS、BET等手段对催化剂的结构、形貌、光学性能进行了表征分析。结果表明：Zr掺杂改性的Zr/g-C3N4光催化剂拓宽了可见光的吸收，增大了比表面积，且降低了光生电子-空穴的复合率，具有较好的光催化活性。可见光照射下，在60 min内，5Zr/g-C3N4对罗丹明B（RhB）的光催化降解率达99.29%，光催化降解过程符合一级动力学方程，其速率常数k= 0.08647 min-1，是纯g-C3N4的8.3倍。捕获剂实验发现降解RhB的主要活性物种为超氧自由基，并推测了可能的反应机理。

Abstract:

Zr-doped Zr/g-C3N4 photocatalysts were prepared by thermal polymerization using guanidine hydrochloride as the precursor and zirconium nitrate as the zirconium source. The structure, morphology and optical properties of the catalysts were characterized and analyzed by means of XRD, SEM, UV-Vis DRS, PL, XPS and BET. The results show that the Zr/g-C3N4 photocatalyst modified by Zr doping broadens the absorption of visible light, increases the specific surface area, reduces the recombination rate of photogenerated electrons and holes, and has good photocatalytic activity. Under visible light irradiation, the photocatalytic degradation rate of 5Zr/g-C3N4 had a degradation rate of 99.29% for Rhodamine B(RhB) within 60 min. The photocatalytic degradation process conformed to the first-order kinetic equation, and its rate constant k= 0.08647 min-1, which was 8.3 times that of pure g-C3N4. The trapping agent experiment found that the main active species for degrading RhB was superoxide radical, and the possible reaction mechanism was speculated.