Optimization of WS2 modified polyaniline for superior photocatalytic degradation and electrochemical detection of pharmaceutical drug

In this study, the strategy of "free two birds with one key" was implemented for the photocatalytic degradation and electrochemical molecularly imprinted polymer (MIP) based detection of nitrofurantoin (NFT) using optimized Z-scheme-based WS2-PANI nanocomposite. The electron micrographs confirmed the formation of interconnected nanofibers of PANI entangled between the WS2 nanosheets. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy have confirmed the presence of quinoid (C -N) and benzenoid (C=N) amine with W -S and S -S bonds. Time-resolved photoluminescence spectroscopy revealed enhanced separation of photoinduced electron-hole pairs (tau avg = 7.76 ns) in optimized nanocomposite which is twice the pristine sample. The pore diameter of the optimized nanocomposite (21.60 nm) was -7 times the pristine WS2, confirmed from BET analysis. The MIP modified WS2-PANI electrode exhibited superior electrochemical detection with a low limit of detection (0.23 nM) with a wide linear range of 100 to 0.01 nM. The optimized nanocomposite yielded superior photocatalytic efficiency (-92 % in 75 min). The generation of reactive oxygen species (center dot O2  and OH center dot) was confirmed by performing electron paramagnetic resonance (EPR) and trapping experiment. The optimized nanocomposite is a potential candidate for environmental remediation applications due to its excellent electrochemical and photocatalytic ability.