ZnO photocatalyst were prepared by precipitation method using ZnC2O4·2H2O and（NH4）2CO3 as raw materials.The photocatalyst was characterized by powder X-ray diffraction（XRD） and transmission electron microscopy（TEM）.The effects of catalyst loading,initial dye concentration,the illuminating distance（the distance between the light and the solution surface） and dye initial pH on the rate constant were investigated by using the methyl orange as the model pollutant.The results show that rate constant,k,to the catalyst loading,empirically as k∝0.62.The rate constant is inversely related to the initial dye concentration and the distance of illuminating,empirically according to the relation k∝-1.18 and k∝[D]-0.88,respectively.Furthermore,the degradation rate increased with increasing pH.In a word,these empirical models were therefore combined as k∝0.62-1.18 [D]-0.88.%以ZnC2O4.2H2O和（NH4）2CO3为原料,采用沉淀法制备了ZnO光催化剂,通过XRD和TEM对所得催化剂进行了表征.以甲基橙为研究对象,研究了催化剂用量、染料初始浓度、光照距离D（紫外灯与染料液面的距离）及染料初始pH值等对光催化反应速率常数（k）的影响.结果表明：反应速率常数与催化剂用量之间的关系为k∝[ZnO]0.62.反应速率常数与染料初始浓度及光照距离成反比关系,其关系分别为k∝[C0]-1.18和k∝[D]-0.88.此外,光催化降解速率随着pH的增加而增大.总之,光催化反应速率常数与各反应因素的影响经验模型为k∝[ZnO]0.62[C0]-1.18[D]-0.88.
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