Rajan Mekha Susan, John Anju, Yoon Minjoong, Thomas Jesty
Research Department of Chemistry, Kuriakose Elias College, Mannanam, Kottayam, Kerala, 686561, India.
Department of Chemistry, Chungnam National University, Daejeon, 34134, Republic of Korea.
Environ Sci Pollut Res Int. 2023 May;30(21):60638-60653. doi: 10.1007/s11356-023-26768-x. Epub 2023 Apr 10.
The existence of antibiotics in aquatic streams destroys water quality and thereby poses serious ecological hitches. Photocatalysis involving nanosemiconductors is an environmentally benign technique for the mineralization of antibiotics. Herein, we prepared a new visible light-sensitive photocatalyst, zeolite Y-supported carbon-doped TiO nanocomposite (zeolite Y-c-TiO), for the elimination of cefazolin antibiotic in wastewater systems. The structural and optical properties of the synthesized nanocomposites were investigated by Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Brunauer-Emmett-Teller surface area analysis (BET) as well as diffuse reflectance spectroscopy (UV-DRS) and photoluminescence spectroscopy (PL). The UV-Vis absorbance spectrum of zeolite Y-c-TiO exhibited a red shift towards longer wavelength with an increase in visible light absorption as compared to pure TiO nanoparticles and zeolite Y-supported TiO nanocomposites (zeolite Y-TiO). Accordingly, the photocatalytic action of the zeolite Y-c-TiO for the degradation of methylene blue was evaluated under solar simulator, and it turned out to be highly efficient (100%) mineralization as compared to TiO-nanoparticles (42%) and zeolite Y-TiO (62%) after 70 min irradiation for a 50mg L methylene blue solution. Radical scavenging experiments revealed the involvement of hydroxyl radicals, superoxide radicals, and photogenerated holes in the degradation process. Consequently, zeolite Y-c-TiO was applied for the photocatalytic degradation of the cefazolin antibiotic in water, and complete degradation of cefazolin (50 mg L) was observed within 6 h of solar light irradiation on zeolite Y-c-TiO. The degradation pathway of cefazolin was proposed by considering various intermediates detected via LC-MS analysis. The study points to the significant potential of zeolite Y-c-TiO photocatalyst for the purification of medicinal wastewater under sunlight.
水体溪流中抗生素的存在会破坏水质，进而造成严重的生态问题。涉及纳米半导体的光催化是一种环境友好型的抗生素矿化技术。在此，我们制备了一种新型可见光敏感光催化剂，即沸石Y负载的碳掺杂TiO纳米复合材料（沸石Y-c-TiO），用于去除废水系统中的头孢唑林抗生素。通过傅里叶变换红外光谱（FT-IR）、粉末X射线衍射分析（XRD）、扫描电子显微镜（SEM）、能量色散X射线分析（EDX）、透射电子显微镜（TEM）、X射线光电子能谱（XPS）、布鲁诺尔-埃米特-泰勒表面积分析（BET）以及漫反射光谱（UV-DRS）和光致发光光谱（PL）对合成的纳米复合材料的结构和光学性质进行了研究。与纯TiO纳米颗粒和沸石Y负载的TiO纳米复合材料（沸石Y-TiO）相比，沸石Y-c-TiO的紫外-可见吸收光谱向更长波长方向发生红移，可见光吸收增加。因此，在太阳模拟器下评估了沸石Y-c-TiO对亚甲基蓝的光催化降解作用，结果表明，对于50mg/L的亚甲基蓝溶液，在照射70分钟后，与TiO纳米颗粒（42%）和沸石Y-TiO（62%）相比，它具有高效的（100%）矿化能力。自由基清除实验表明，羟基自由基、超氧自由基和光生空穴参与了降解过程。因此，将沸石Y-c-TiO应用于水中头孢唑林抗生素的光催化降解，在太阳光照射沸石Y-c-TiO 6小时内观察到头孢唑林（50mg/L）完全降解。通过液相色谱-质谱分析检测到的各种中间体，提出了头孢唑林的降解途径。该研究表明，沸石Y-c-TiO光催化剂在阳光下净化医药废水方面具有巨大潜力。
