可见光下Cu2O/TiO2催化臭氧氧化头孢曲松钠性能研究

Photocatalytic ozonation of ceftriaxone sodium by Cu2O/TiO2 under visible light

抗生素是治疗各种传染病的常用药物,但残留在水环境中的抗生素会对生态系统造成威胁。因此,探索去除水环境中抗生素的有效方法具有重要意义。由于光催化臭氧氧化技术可以高效降解和矿化水体中的污染物,该技术受到广泛关注。本工作通过浸渍-化学还原法制备Cu_(2)O/TiO_(2)复合材料并将其作为可见光催化臭氧氧化头孢曲松钠(CRO)的催化剂。利用X射线衍射仪(XRD)、傅里叶变换红外光谱仪(FT-IR)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、比表面积分析仪(BET)和紫外-可见漫反射光谱仪(UV-Vis DRS)对Cu_(2)O/TiO_(2)形貌结构和光学性能进行表征,考察了Cu_(2)O/TiO_(2)配比、Cu_(2)O/TiO_(2)投加量、臭氧浓度、头孢曲松钠初始浓度、溶液初始pH值等因素对可见光催化臭氧氧化头孢曲松钠的影响。结果表明,Cu_(2)O对TiO_(2)的掺杂改性使材料孔容和平均孔径增大,能带宽度减小,可见光下的催化性能增强。在Cu_(2)O:TiO_(2)摩尔比为0.2:1、可见光照射120 min、溶液pH值为6.12、头孢曲松钠浓度为10 mg/L、Cu_(2)O/TiO_(2)投加量为0.2 g/L、臭氧浓度为1.5 mg/L条件下,头孢曲松钠和TOC的降解率分别达到81.05%和52.16%,臭氧利用率达到50.84%。自由基捕获实验表明,可见光催化臭氧氧化头孢曲松钠的过程中光生空穴(h^(+))和超氧自由基(·O_(2)^(-))起主要作用。5次循环使用实验结果表明,Cu_(2)O/TiO_(2)有较好的可重复利用性。本研究结果表明,对于水体中的头孢曲松钠,可见光催化臭氧氧化是一种很有前途的治理技术。

Antibiotics are commonly used drugs for the treatment of various infectious diseases in humans and animals,but the residual antibiotics released into the aquatic environment will threaten the ecological system.Therefore,it is important to explore efficient methods to remove antibiotics from the water environment.Photocatalytic ozonation technology has received extensive attention for its effective degradation and mineralization of persistent organic pollutants from the water matrix.In this work,Cu_(2)O/TiO_(2)composite was prepared by the impregnationchemical reduction method and was used as a catalyst for photocatalytic ozonation of ceftriaxone sodium(CRO)under visible light irradiation.The morphology,structure,and optical properties were investigated by X-ray diffraction(XRD),Fourier transforms infrared spectroscopy(FT-IR),scanning electron microscope(SEM),transmission electron microscopy(TEM),nitrogen adsorption-desorption isotherms(BET)and ultraviolet-visible diffuse reflection(UV-Vis DRS).The effects of Cu_(2)O/TiO_(2)ratio,Cu_(2)O/TiO_(2)dosage,ozone concentration,initial concentration of ceftriaxone sodium,and initial pH value of the solution on visible-light-induced photocatalytic ozonation of ceftriaxone sodium were comprehensively investigated.The results showed that the doping of Cu_(2)O on TiO_(2)increased the specific surface area and pore volume,reduced the energy gap,and improved the catalytic performance under visible light.The photocatalytic ozonation process had achieved a much higher removal rate of ceftriaxone sodium from an aqueous solution than the photocatalysis and ozonation processes.When the molar ratio of Cu_(2)O:TiO_(2)was 0.2:1,the visible light irradiation time was 120 min,the initial pH value of the solution was 6.12,the concentration of ceftriaxone sodium was 10 mg/L,the dosage of Cu_(2)O/TiO_(2)was 0.2 g/L and ozone concentration was 1.5 mg/L,the removal rates of ceftriaxone sodium and TOC were 81.05% and 52.16%,respectively,and the ozone utilization rate was 50.84%.The free radical capture experiments showed that photogenerated holes(h^(+))and superoxide radicals(·O_(2)^(-))played a major role in the visible-light-induced photocatalytic ozonation of ceftriaxone sodium.Moreover,Cu_(2)O/Ti O_(2)exhibited satisfactory stability and reusability for 5 consecutive cycles.The findings of this study suggest that the photocatalytic ozonation process induced by visible light is a promising treatment technology for the abatement of ceftriaxone sodium pollution in an aqueous solution.