复合改性纳米TiO_(2)催化降解五氯苯酚的试验研究

An experimental study on catalytic degradation of chlorophenasic acid by compound modified nano-TiO_(2)

为了探究纳米C-Co/TiO_(2)催化剂降解五氯苯酚的动力学特性,采用溶胶-凝胶法,制备了C、Co双元素掺杂复合改性的纳米C-Co/TiO_(2)催化剂。利用XRD、SEM-EDS、UV-vis进行表征分析,结果表明:掺杂C、Co元素后,纳米C-Co/TiO_(2)晶型未发生改变,特征峰强度增强,晶体结晶性好,粒径约为12.08 nm;催化剂表面呈现球状堆积形貌,比表面积大,有利于反应物吸附脱附;与纯TiO_(2)相比,催化剂带隙能降低,对可见光的响应性增强。结合降解过程中产物的紫外吸收光谱,探究五氯苯酚的催化降解机理。根据试验检测结果,分析拟合初始浓度与降解速率的线性关系,得到光催化降解五氯苯酚的L-H模型动力学方程:r0=0.38491 0.0951C_(0)/1+0.0951C_(0)。

In order to investigate the dynamic characteristics of nano C-Co/TiO_(2) catalyst degrading chlorophenasic acid,compound modified nano C-Co/TiO_(2) doped with carbon and cobalt was prepared by sol-gel method.Using XRD,SEM-EDS,UV-vis to characterize and analyze the said compound catalyst,the results showed that,after doping C and Co,the crystal pattern of nano C-Co/TiO_(2) was unchanged,the characteristic peak intensity increased,the crystal crystallinity was good,and the grain diameter was 12.08 nm.The surface of the catalyst appeared spherical accumulation shape,the specific surface area was large,which was of benefit to the adsorption and desorption of the reactant.Compared to pure TiO_(2),the said catalyst had lower band-gap energy,and stronger responsibility to visible light.According to the ultraviolet absorption spectra of the products during the degradation process,the catalytic degradation mechanism of chlorophenasic acid was investigated.Based on the measurement result of the experiment,the linear relationship between the initial concentration and the degradation rate was analyzed;besides,the L-H model kinetic equation of photocatalytic degradation of chlorophenasic acid was obtained:r0=0.38491 0.0951C_(0)/1+0.0951C_(0).