Environmental Nanotechnology Laboratory, Department of Environmental Science and Engineering, Indian Institute of Technology (ISM), Dhanbad, 826004, Jharkhand, India; Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India.
Environmental Nanotechnology Laboratory, Department of Environmental Science and Engineering, Indian Institute of Technology (ISM), Dhanbad, 826004, Jharkhand, India.
Chemosphere. 2024 Sep;364:143198. doi: 10.1016/j.chemosphere.2024.143198. Epub 2024 Aug 30.
The occurrence of xenobiotic pollutants in the aquatic environment troubling the present and future generation. Persistent Organic Pollutants (POPs) is one such class of xenobiotic that was dominant in that category. In the present paper, a competent visible light driven heterojunction photocatalyst combining Bismuth niobate and g-CN was developed for the effective removal of Bisphenol A (BPA), a notable POP. Before constructing the heterostructure the calcination temperature for bismuth niobate synthesis was optimised for achieving most proficient photocatalysis. A phase change in the crystal structure of bismuth niobate was apparent. The BiNbO at 300-500 °C transformed to BiNbO at 600-700 °C and to orthorhombic BiNbO at 900 °C as the temperature was enhanced. With the increment in the temperature the light absorbance of the materials enhanced in UV and reduced in visible light. Thus, the bismuth niobate obtained by calcining at 500 °C demonstrated highest BPA removal under sunlight was chosen for heterojunction construction. After the heterojunction construction with g-CN the crystal lattice strain was observed to be reduced for all composites, and a greater mobility of charge carriers was observed within the composite. The presence of either of the materials resulted in a different band structure and thus Type II and Z-scheme pathway was inferred. A commendable photocatalytic activity was observed for B1.5G and BG1.5 under sunlight and LED light respectively. Hight amount of g-CN in the BG1.5 resulted in maximum absorbance in LED light. Superoxide radicals (*O) radicals were observed as major radicals for B1.5G composite, whereas both *O and holes (h) were the major radicals in case of BG1.5.
外源性污染物在水生环境中的出现给现在和未来的几代人带来了困扰。持久性有机污染物 (POPs) 就是这样一类外源性污染物，它们在这一类别中占主导地位。在本文中，开发了一种结合了铌酸铋和 g-CN 的高效可见光驱动异质结光催化剂，用于有效去除双酚 A (BPA)，这是一种显著的 POP。在构建异质结构之前，优化了合成铌酸铋的煅烧温度，以实现最有效的光催化。铌酸铋的晶体结构发生了相变。BiNbO 在 300-500°C 下转变为 BiNbO 在 600-700°C 和正交 BiNbO 在 900°C 下，随着温度的升高。随着温度的升高，材料的光吸收率在紫外光下增强，在可见光下减弱。因此，选择在 500°C 下煅烧得到的铌酸铋在太阳光下表现出最高的 BPA 去除率，用于异质结构的构建。与 g-CN 构建异质结后，观察到所有复合材料的晶格应变减小，并且在复合材料中载流子的迁移率增加。两种材料中的任何一种都会导致不同的能带结构，因此推断出存在 II 型和 Z 型途径。B1.5G 和 BG1.5 在阳光和 LED 光下分别表现出令人瞩目的光催化活性。在 BG1.5 中，g-CN 的高含量导致在 LED 光下的最大吸收。在 B1.5G 复合材料中观察到超氧自由基 (*O) 自由基是主要自由基，而在 BG1.5 中，*O 和空穴 (h) 都是主要自由基。
