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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SiO_2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TiO_2的复合催化剂,研究了弱光(光强小于1mW·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La~(3+)掺杂TiO_2-SiO_2,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,La~(3+)掺杂TiO_2-SiO_2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TiO_2-GO和La~(3+)掺杂TiO_2-GO中,TiO_2粒子粒径小于10nm且均匀负载于GO的表面.醇溶剂热还原处理可使TiO_2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TiO_2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.
In order to obtain photocatalysts suitable for photodegradation of organic pollutants in seawater, nano-SiO 2 particles and graphene oxide GO were selected as carrier respectively, and TiO 2 -based composite catalysts were prepared by adsorption-phase reaction and heat treatment. The effects of low light intensity Less than 1mW · cm ~ (-3)), the photocatalytic degradation of phenol in seawater was studied.The results showed that the adsorption of the La 3+ -doped TiO 2-SiO 2 by the adsorption phase reaction combined with the surface hydrophilicity Strong and poor adsorption capacity of phenol, it is difficult to overcome the interference of salt ions and effectively degrade high concentrations of phenol in simulated seawater. However, after the adsorption phase reaction combined with alcohol solvent thermal reduction, the surface of La ~ (3+) doped TiO_2-SiO_2 catalyst But its hydrophilicity is weakened significantly, but the catalyst can not form a stable suspension in the simulated seawater.In TiO 2 -GO and La 3+ -doped TiO 2 -GO obtained by adsorption phase reaction, the particle size of TiO 2 is less than 10 nm And uniformly loaded on the surface of GO. Alcohol solvothermal thermal reduction can form crystalline structure of TiO 2 to improve its catalytic activity, meanwhile reduce the oxygen-containing groups on GO surface and reduce the hydrophilicity of catalyst surface. Catalyst adsorption capacity of phenol and anti-interference ability of salt ions.In addition, the reduction of GO and small particles of TiO 2 particles in close contact, so that photogenerated electrons can quickly transfer to the reduction of GO surface, increase photogenerated charge separation rate and further enhance the catalyst Photodegradation performance.