Aguedach Abdelkahhar, Brosillon Stephan, Morvan Jean, Lhadi El Kbir
Laboratoire de l'Eau et environnement, Université Chouaïb Doukkali, Faculté des Sciences, BP.20, El Jadida, Maroc.
J Hazard Mater. 2008 Jan 31;150(2):250-6. doi: 10.1016/j.jhazmat.2007.04.086. Epub 2007 Apr 24.
Reactive black 5 (RB5), an azo dye, was degraded by using UV-irradiated TiO(2) coated on non woven paper with SiO(2) as a binder. The adsorption capacity of the photocatalyst was studied at natural pH, superior to pH(pzc) of the binder, for various ionic strengths. Different salts such as NaCl, KCl, CaCl(2), LiCl, Ca(NO(3))(2) were used to increase the ionic strength. The presence of salt increased the adsorption capacity. The electrostatic interactions between dye and oxide surface charges (TiO(2)/SiO(2)) is very important in the adsorption phenomena. The effect of the ionic strength of the solution on photocatalyst degradation was studied. The rate of degradation was increased by the presence of salts in the range of the experimental conditions. The increase of the initial decolorization rate was observed in the following order: Ca(2+)>K(+)>Na(+)>Li(+). Experiments with different anions (Cl(-), NO(3)(-)) had shown that nitrate was an indifferent electrolyte for the adsorption and photodegradation of the dye on SiO(2)/TiO(2).
活性黑5（RB5）是一种偶氮染料，通过使用以二氧化硅（SiO₂）作为粘合剂涂覆在无纺布上的紫外线照射的二氧化钛（TiO₂）进行降解。在自然pH值（高于粘合剂的零电荷点pH值）下，针对不同离子强度研究了光催化剂的吸附容量。使用不同的盐（如氯化钠、氯化钾、氯化钙、氯化锂、硝酸钙）来提高离子强度。盐的存在增加了吸附容量。染料与氧化物表面电荷（TiO₂/SiO₂）之间的静电相互作用在吸附现象中非常重要。研究了溶液离子强度对光催化剂降解的影响。在实验条件范围内，盐的存在提高了降解速率。观察到初始脱色速率的增加顺序为：Ca²⁺>K⁺>Na⁺>Li⁺。使用不同阴离子（Cl⁻、NO₃⁻）的实验表明，硝酸盐是染料在SiO₂/TiO₂上吸附和光降解的惰性电解质。
