金属掺杂WO_(3)光催化降解四环素性能及机理

Photocatalytic degradation and mechanism of tetracycline by metal doped WO_(3)

由于广谱抗生素四环素的广泛使用,其在水环境中的残留已引起严重的健康问题.本文制备了Ag、La和Cu 3种金属元素掺杂WO_(3)用于增强四环素的光催化降解.采用SEM、TEM、XRD、XPS、FTIR和BET比表面积对制备光催化剂进行了表征.结果表明,金属掺杂WO_(3)有效提高了四环素的去除效率,其中,Cu掺杂WO_(3)(Cu-WO_(3))光催化性能最为优异,反应10 min四环素去除效率达到100.0%.在20~50℃条件下四环素均能被有效地光催化降解,pH=5~7时更有利于四环素的光降解.制备材料具有出色的稳定性和重复利用性,循环4次后对四环素的去除率仅降低4.1%.金属元素的掺杂降低了WO_(3)的电子传输阻力,增强了光电流的产生,促进了活性物种的生成,从而提升了对四环素的光降解性能.四环素的光降解是不同活性物质(h^(+)、H_(2)O_(2)、·O_(2)^(-)和^(1)O_(2))共同作用的结果,提供了3种四环素降解途径.基于上述结果,金属掺杂可以作为提升WO_(3)光催化性能的有效方法,Cu-WO_(3)可以作为长期稳定的四环素光降解催化剂.

Due to the widespread use of the broad-spectrum antibiotic tetracycline,its residues in aquatic environments have caused serious health problems.This work prepared WO_(3)doped with Ag,La,and Cu for enhanced photocatalytic degradation of tetracycline.The prepared photocatalyst was characterized by SEM,TEM,XRD,XPS,FTIR,and BET specific surface area.Metal doped WO_(3)effectively improves the removal efficiency of tetracycline,among which Cu doped WO_(3)(Cu-WO_(3))has the most excellent photocatalytic performance,with a removal efficiency of 99.0%after 10 minutes of reaction.Prepared photocatalyst showed excellent photocatalytic degradation performance at 20~50℃,and pH=5~7 was more conducive to the photodegradation of tetracycline.Prepared photocatalyst has excellent stability and reusability,with a reduction of only 4.1%in the removal rate of tetracycline after 4 cycles.The doping of metal elements reduces the electronic transmission resistance of WO_(3),enhances the generation of photocurrent,promotes the generation of active species,and thus improves the photodegradation performance of tetracycline.The photodegradation of tetracycline results from the joint action of different active substances(h^(+),H_(2)O_(2),•O_(2)^(-)and ^(1)O_(2)),providing three tetracycline degradation pathways.Based on the above results,metal doping can be an effective method to improve the photocatalytic performance of WO_(3),and Cu-WO_(3)can be used as a long-term stable tetracycline photodegradation catalyst.