沉淀剂对Co_3O_4光催化性能的影响

Effect of precipitants on photocatalytic property of Co_3O_4 particles

分别以CO(NH_2)_2、Na_2C_2O_4、Na_2CO_3和(NH_4)_2CO_3为沉淀剂,采用水热-热分解法制备黑色Co_3O_4颗粒。通过XRD、SEM对样品的结构和形貌进行了分析。结果表明,选用CO(NH_2)_2、Na_2C_2O_4、Na_2CO_3和(NH_4)_2CO_3为沉淀剂所制备的Co_3O_4分别呈片层堆叠状、棒状、薄的纳米片状和具有二级结构的绣球状。通过降解甲基橙溶液研究了沉淀剂对Co_3O_4光催化性能的影响,结果发现,以CO(NH_2)_2、Na_2C_2O_4、Na_2CO_3和(NH_4)_2CO_3为沉淀剂所制备的Co_3O_4对甲基橙溶液的降解率分别达到48%、92%、95%和97%,以(NH_4)_2CO_3为沉淀剂所制备的Co_3O_4由于具有二级结构的绣球状结构,与溶液的接触面积大,有利于对光的吸收和利用,对甲基橙的催化降解效果最好,在30 min降解率可达90%。

Black Co3O4 particles are prepared by hydrothermal and thermal-decomposition method using CO（NH2）2,Na2C2O4,Na2CO3and（ NH4）2CO3as precipitating agent,respectively. The structure and morphology of products are analyzed by X-ray diffractometry（ XRD） and scanning electron microscope（ SEM）. The results show that the nano-thin sheet,rod,lamellar and hydrangea-like Co3O4 particles can be obtained when CO（NH2）2,Na2C2O4,Na2CO3and（ NH4）2CO3are used as precipitating agent,respectively. The influence of precipitants on photocatalytic property of Co3O4 is evaluated through the degradation of methyl orange solution. The degradation rate of methyl orange solution reaches 48%,92%,95% and 97% using the Co3O4 particles as catalysts which are prepared with CO（NH2）2,Na2C2O4,Na2CO3and（ NH4）2CO3as precipitating agent,respectively. The photocatalytic property Co3O4 prepared with（ NH4）2CO3as precipitant is the best,because of its secondary and hydrangea-like structure which are helpful to increase the contact area of the solution and thus improve the absorption and utilization of light. The degradation rate of methyl orange can reach 90% after 30 min.