A novel and stretchable carbon-nanotube/Ni@TiO 2 :W photocatalytic composite for the complete removal of diclofenac drug from the drinking water

• Published in: Journal of environmental sciences (China) Vol. 126; p. 575
• Main Authors: Valadez-Renteria, Ernesto, Perez-Gonzalez, Rafael, Gomez-Solis, Christian, Diaz-Torres, Luis Armando, Encinas, Armando, Oliva, Jorge, Rodriguez-Gonzalez, Vicente
• Format: Journal Article
• Language: English
• Published: Netherlands 01.04.2023
• Subjects: Diclofenac; Drinking Water; Electrons; Nanotubes, Carbon; Oxygen; Carbon nanotubes; Stretchable composite; TiO; Pharmaceutical contaminant; Photocatalysis; Diclofenac
• ISSN: 1001-0742
• DOI: 10.1016/jjes.2022.05.028

We present the structural, morphological and photocatalytic properties of stretchable composites made with carbon nanotubes (CNTs), silicon rubber and Ni@TiO :W nanoparticles (TiWNi NPs) with average size of 37 ± 2 nm. Microscopy images showed that the TiWNi NPs decorated the surface of the CNT fibers, which are oriented in a preferential direction. TiWNi NPs presented a mixture of anatase/rutile phases with cubic structure. The performance of the TiWNi powders and stretchable composites was evaluated for the photocatalytic degradation of diclofenac (DCF) anti-inflammatory drug under ultraviolet-visible light. The results revealed that the maximum DCF degradation percentages were 34.6%, 91.9%, 97.1%, 98.5% and 100% for the CNT composite (stretched at 0%), TiWNi powders, CNT + TiWNi (stretched at 0%), CNT + TiWNi (stretched at 50%) and CNT + TiWNi (stretched at 100%), respectively. Thus, stretching the CNT + TiWNi composites was a good strategy to enhance the DCF degradation percentage from 97.1% to 100%, since stretching created additional defects (oxygen vacancies) that acted as electron sink, delaying the electron-hole recombination, and favors the DCF degradation. Raman/absorbance measurements confirmed the presence of such defects. Moreover, the reactive oxygen species (ROS) were determined by the scavenger's experiments and found that the main ROS were the ·OH and O radicals, which attacked the DCF molecules, causing their degradation. The results of this investigation confirmed that the stretchable CNT/TiWNi-based composites are a viable alternative to remove pharmaceutical contaminants from water and can be manually separated from the decontaminated water, which is unviable using photocatalytic powders.