Real-time degradation of methylene blue using bio-inspired superhydrophobic PDMS tube coated with Ta-ZnO composite

Abstract

Dyes are widely used in a variety of industrial applications for aesthetical purpose as well as to provide the color of their products. Huge amount of dye-containing wastewater is released after their processing, posing a risk of environmental contamination. This has prompted the development of low-cost, highly reliable, and long-term technologies for effluent remediation. In this work, the synthesized tantalum (Ta)-doped Zinc oxide (ZnO) composite coated over the bioinspired polymeric platform has been reported for the decolouration of methylene blue (MB) dye when exposed to UV light. These structures were carefully investigated using a scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and a contact angle (CA) goniometer. The contact angle results show the contact angle of 108˚ for pure polydimethylsiloxane (PDMS) and 168˚ for bio-inspired PDMS with Ta-doped ZnO composite leading to a superhydrophobic surface. This superhydrophobic bio-inspired polymeric platform was modified by optimizing the surface roughness and coating it with low-surface-energy Ta-ZnO NWs composites, paving the way for it to be envisioned in "self-cleaning" water treatment facilities. When exposed to UV light, the MB dye degradation time was reduced from 150 mins to 105 mins, indicating that the synthesized Ta-doped ZnO NWs composite is more effective than ZnO. These photocatalysts lead to "waste control using Ta-ZnO NWs composites," which opens up new possibilities for flexible and biocompatible environmental remediation platforms. In this study, real-time MB dye degradation is also monitored using the Internet of things (IoT) technique by integrating a NodeMCU microcontroller board as a control center and a pH sensor as a tool for detecting the change in pH value of the MB dye under UV light exposure.