ZnO基光催化材料的制备及其光催化性能研究

Preparation and Photocatalytic Property of ZnO Photocatalytic Materials

ZnO作为一种使用普遍的光催化剂,它的化学性质稳定、廉价易得、无毒。首先以Zn(Ac)2和(CH3)4NOH为原料,通过溶胶-凝胶法制备ZnO干胶,以苯酚溶液模拟有机废水,详细研究了原料不同摩尔比、不同煅烧温度、不同煅烧时间下所合成的ZnO材料及ZnO不同投入量催化降解苯酚的性能。之后以AgNO3为掺杂剂,在上述最佳合成条件下,采用超声-旋蒸法合成了一系列Ag掺杂量不同的Ag-ZnO光催化剂,并详细研究了不同Ag掺杂量、不同热处理温度和时间及Ag-ZnO的不同投入量对苯酚溶液的光催化降解率。XRD测试结果表明,上述条件下所得ZnO和Ag-ZnO材料结晶度高、无杂质,与标准图谱一致;UV-vis数据表明掺杂Ag后提高了ZnO的吸收范围。催化降解苯酚结果表明,当Zn(Ac)2和(CH3)4NOH原料配比为1∶2、煅烧温度为500℃、煅烧时间为2h所得ZnO材料投入量为0.10g/100mL苯酚、紫外灯光灯照射3h时,苯酚的降解率为62.8%;当Ag的掺杂量为3%时,在上述条件下所得的Ag-ZnO材料对苯酚的降解率为79.5%,银掺杂后所得的光催化材料明显提高了苯酚的降解率。

As a commonly used photocatalyst,ZnO shows the stable chemical property,low-cost,easy availability,and non-toxicity.Zn(Ac)2 and(CH3)4NOH were used as raw materials to prepare ZnO dry gel by a sol-gel method.The organic wastewater was simulated by the phenol solution.The photocatalytic degradation performance of ZnO synthesized with different proportions of raw materials and variable calcination temperatures and times were studied.Then,using AgNO3 as a dopant,a series of Ag-ZnO photocatalysts with different amounts of Ag doping were synthesized via an ultrasonic-spin evaporation method under the optimal synthetic conditions.The effects of Ag doping and calcination temperatures and times of the obtained Ag-ZnO photocatalysts on photocatalytic degradation of phenol were also studied.The XRD data indicates that the photocatalysts show high crystallinity and purity while the UV-vis data reveal that Ag doping may extend the absorption range of ZnO photocatalysts.The catalytic degradation rate of phenol may reach 62.8%for the ZnO photocatalyst(0.10 g/100 mL)obtained at a ratio of 0.5 for Zn(Ac)2 and(CH3)4NOH under a calcination temperature of 500℃and a calcination time of 2 h.The Ag-ZnO photocatalyst with an Ag doping concentration at 3%under a calcination temperature of 500℃and a calcination time of 2 h shows a higher photocatalytic performance of 79.5%for degradation of phenol,which proves that Ag doping could significantly improve the photocatalytic degradation rate.