Highly effective and stable MWCNT/WO3 nanocatalyst for ammonia gas sensing, photodegradation of ciprofloxacin and peroxidase mimic activity

Abstract

The present study discusses the ammonia (NH3) sensing characteristics, photocatalytic degradation of emerging pollutants, and peroxidase mimic activity of multifunctional multi-walled carbon nanotube-tungsten oxide nanocomposite (MWCNT/WO3) prepared by conventional solvothermal method. The prepared MWCNT/WO3 nanocomposites were characterized by various analytical techniques like XRD, Raman, XPS, N2 adsorption, FESEM with elemental analysis and diffuse reflection spectroscopy. The prepared 1% MWCNT/WO3 nanocomposite showed better gas sensing performance for the NH3 vapors at 10–100 ppm than the pristine WO3 and the response and recover time of about 13 and 15s towards 20 ppm of ammonia (NH3) was achieved. The photocatalytic activity of MWCNT/WO3 towards organic dyes such as Rhodamine-B (Rh.B) methylene blue (MB) and pharmaceutical compound ciprofloxacin (CIP) were studied and achieved above 90% degradation at 160 min for CIP and 60 min for MB and Rho-B respectively. The radicle scavenging activity for MWCNT/WO3 nanocomposite showed the predominant formation of hydroxyl (OH•) and superoxide radicle (•O2−). Further, the MWCNT/WO3 nanocomposite showed peroxidase mimic activity and exhibit the limit of detection (LOD) of about 321 nM. From the overall analysis, MWCNT/WO3 hybrid seems to have potential characteristics that can be explored for multiple functional applications.