Ghosh Sougata, Imboon Tanawat, Layek Rashbihari, Salunke Gayatri, Parihar Vijay Singh, Khumphon Jeerawan, Webster Thomas J, Sutar Santosh, Kityakarn Sutasinne, Issro Chaisak, Khamboonrueang Dusadee, Thongmee Sirikanjana
Department of Physics, Faculty of Science, Kasetsart University, Bangkok, Thailand.
Department of Microbiology, School of Science, RK. University, Rajkot, Gujarat, India.
Front Chem. 2025 Apr 15;13:1576504. doi: 10.3389/fchem.2025.1576504. eCollection 2025.
Doping-associated surface modification is a powerful strategy to enhance the photocatalytic potential of n-type semiconductor nanomaterials. Silver (Ag) is one of the most effective dopants that can result in the retardation of the electron hole recombination-generating Schottky barrier at the TiO interface with a simultaneous extension of absorption to the visible region. This work presents a study on the effect of catechin, a bioactive principle polyphenol compound found in various plants, on the synthesis, Ag-doping and stabilization of TiO nanoparticles (TiONPs). The nanoparticles were irregular in shape with sizes ranging from 19 to 30 nm. Ag-TiONPs were fabricated using TiO as a precursor and 1%, 3%, and 5% AgNO as a doping agent. The average particle size of 1%Ag-TiONPs, 3%Ag-TiONPs, and 5%Ag-TiONPs was 27.3 ± 7.5 nm, 29.8 ± 9.6 nm, and 25.0 ± 9.0 nm, respectively. High-resolution transmission electron microscopy (HRTEM) showed lattice fringes with an interplanar spacing of 0.23 nm corresponding to the Ag (111) plane in addition to the presence of the anatase phase of TiO. Fourier transform infrared (FTIR) spectra exhibited a broad peak around 400-800 cm that was attributed to Ti-O-Ti stretching vibrations which was slightly shifted in Ag-TiONPs due to changes in the local bonding environment around Ti atoms caused by interactions with Ag. Catechin loading in the TiONPs and Ag-TiONPs was between 1.55 and 3.3 wt. %. TiONPs, 1%Ag-TiONPs, 3%Ag-TiONPs, and 5%Ag-TiONPs exhibited superior photocatalytic degradation of methylene blue dye up to 78%, 87%, 91%, and 92%, respectively, and RhB dye up to 92%, 94%, 97% and 99%, respectively, with a pseudo-first-order reaction kinetics. Furthermore, its recyclability was also demonstrated for three cycles. The simplicity of fabrication and superior photocatalytic performance of TiO demonstrated here make this green route advantageous for environmental applications to treat dye contaminated effluent as well as for numerous other applications.
掺杂相关的表面修饰是增强n型半导体纳米材料光催化潜力的有效策略。银（Ag）是最有效的掺杂剂之一，它能延缓电子空穴复合，在TiO界面处形成肖特基势垒，同时将吸收光谱扩展到可见光区域。本研究探讨了儿茶素（一种存在于多种植物中的生物活性多酚化合物）对TiO纳米颗粒（TiONPs）的合成、Ag掺杂及稳定性的影响。这些纳米颗粒形状不规则，尺寸在19至30纳米之间。以TiO为前驱体，1%、3%和5%的AgNO为掺杂剂制备了Ag-TiONPs。1%Ag-TiONPs、3%Ag-TiONPs和5%Ag-TiONPs的平均粒径分别为27.3±7.5纳米、29.8±9.6纳米和25.0±9.0纳米。高分辨率透射电子显微镜（HRTEM）显示，除了TiO的锐钛矿相外，还有对应于Ag（111）平面、面间距为0.23纳米的晶格条纹。傅里叶变换红外（FTIR）光谱在400 - 800厘米附近有一个宽峰，归因于Ti - O - Ti的伸缩振动，由于与Ag相互作用导致Ti原子周围局部键合环境的变化，该峰在Ag-TiONPs中略有位移。TiONPs和Ag-TiONPs中的儿茶素负载量在1.55至3.3重量%之间。TiONPs、1%Ag-TiONPs、3%Ag-TiONPs和5%Ag-TiONPs对亚甲基蓝染料的光催化降解率分别高达78%、87%、91%和92%，对罗丹明B染料的光催化降解率分别高达92%、94%、97%和99%，符合准一级反应动力学。此外，还证明了其可循环使用三个周期。本文展示的TiO制备方法简单且光催化性能优异，使得这种绿色途径在处理染料污染废水及众多其他环境应用中具有优势。
