研究报告

  • 许智勇,李冰蕊,潘家豪,王挺,吴礼光,祝轶琛.TiO2复合催化剂弱光催化降解模拟海水中苯酚及其催化活性的影响[J].环境科学学报,2017,37(12):4593-4601

  • TiO2复合催化剂弱光催化降解模拟海水中苯酚及其催化活性的影响
  • Photodegradation of phenol in artificial seawater by TiO2 composite catalysts under weak UV irradiation
  • 基金项目:国家自然科学基金资助项目(No.20806071,21076190)
  • 作者
  • 单位
  • 许智勇
  • 浙江工商大学环境科学与工程学院, 杭州 310012
  • 李冰蕊
  • 浙江工商大学环境科学与工程学院, 杭州 310012
  • 潘家豪
  • 浙江工商大学环境科学与工程学院, 杭州 310012
  • 王挺
  • 浙江工商大学环境科学与工程学院, 杭州 310012
  • 吴礼光
  • 浙江工商大学环境科学与工程学院, 杭州 310012
  • 祝轶琛
  • 浙江工商大学环境科学与工程学院, 杭州 310012
  • 摘要:为了获得适用于海水中有机污染物光降解催化剂,分别选用纳米SiO2粒子和氧化石墨烯GO为载体,利用吸附相反应技术并结合热处理过程制备了基于TiO2的复合催化剂,研究了弱光(光强小于1 mW·cm-3)激发下复合催化剂光催化降解模拟海水中苯酚.结果表明,吸附相反应技术结合焙烧得到的La3+掺杂TiO2-SiO2,表面亲水性较强和对苯酚吸附能力较弱,难以克服盐离子的干扰并有效降解模拟海水中高浓度苯酚.而吸附相反应技术结合醇溶剂热还原处理后,La3+掺杂TiO2-SiO2催化剂表面亲水性显著减弱,但该催化剂在模拟海水中不能形成稳定的悬浮体系.吸附相反应技术得到的TiO2-GO和La3+掺杂TiO2-GO中,TiO2粒子粒径小于10 nm且均匀负载于GO的表面.醇溶剂热还原处理可使TiO2形成晶型结构,从而提高其催化活性,同时还能将GO表面的含氧基团还原,降低催化剂表面亲水性.从而提升催化剂对苯酚的吸附能力和对盐离子的抗干扰能力.另外,还原GO与小粒径TiO2粒子紧密结合,使光生电子能很快转移至还原GO表面,增大光生电荷分离率,进一步提升催化剂的光降解性能.
  • Abstract:In order to remove organic pollutants from the seawater by photodegradation, SiO2 nanoparticles and graphene oxide (GO) were employed as supports to prepare TiO2 multi-component photocatalysts by adsorption phase synthesis (APS) and different heat treatment processes. The photodegradation of phenol in artificial seawater was carried out under irradiation of weak UV light (light intensity is less than 1 mW·cm-3) with different initial concentration. La3+ doped TiO2-SiO2 by APS after calcinations could not overcome the disturbance of salt ions, and it showed weak adsorption capacity for phenol and hydrophilic surface, revealing low photocatalytic activity for phenol with high concentration. After the solvent thermal reduction treatment, the surface hydrophilicity of La3+ doped TiO2-SiO2 decreased significantly. However, it could not disperse well in artificial seawater to form a stable suspension. Via APS, TiO2 nanoparticles with size < 10 nm distributed homogeneously on GO surface in both TiO2-GO and La3+ doped TiO2-GO. After the solvent heat treatment, the formation of crystal TiO2 enhanced photocatalytic activity. The oxygenated functional groups on GO surface in catalysts would be reduced, and the surface hydrophilicity of catalysts decreased simultaneously. It enhanced the adsorption capacity of phenol and the resistance to salt ions of catalysts. In addition, the interaction between the reduced GO and TiO2 particles led to the rapid transfer of photogenerated electrons from TiO2 to reduced GO, which increased the separation efficiency of photogenerated charge carriers and further improved photodegradation performance of the catalysts.

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