Abstract
This study investigated the design and construction of a nucleotide probe on a
Bi2WO6/NbSe2@Nb4N3Tx MXene S-scheme heterojunction for the
photoelectrochemical detection and degradation of efavirenz. The materials were
synthesized using a combination of hydrothermal, controlled calcination, and
ultrasonication methods. Bi2WO6 was synthesized through hydrothermal methods,
while NbSe2 followed a ball milling and calcination approach. Nb4N3Tx MXene was
obtained by exfoliating the MAX phase using in-situ prepared HF from a LiF and HCl
mixture. The synthesized materials were characterized using X-ray diffraction
(XRD), scanning electron microscopy (SEM), transmission electron microscopy
(TEM), energy dispersive X-ray spectrometry (EDS), Raman spectroscopy, Fourier
transform infrared spectroscopy (FTIR), UV-visible diffuse reflectance spectroscopy
(UV-DRS), and photoluminescence spectroscopy (PL).
XRD analysis confirmed the successful preparation of orthorhombic Bi2WO6 phase,
hexagonal phases of NbSe2 and Nb4N3Tx, and their respective binary and ternary
nanocomposites. While SEM analysis revealed a multicomponent design where a
hexagonal-like NbSe2 nanorod and Nb4N3Tx MXene nanosheets formed a support
network for reticulated Bi2WO6 micro-flowers.
Electrochemical analysis, including cyclic voltammetry (CV), electrochemical
impedance spectroscopy (EIS), chronoamperometry measurements, open circuit
potential (OCP), and Mott Schottky analysis, confirmed the formation of an Sscheme
heterojunction from n and p-type semiconductors belonging to Bi2WO6 and
NbSe2, respectively. This unique architecture established a dual-drive chargetransfer
channel, effectively promoting the separation of charge carriers. One path
formed a Schottky junction between NbSe2 and Nb4N3Tx MXene, while the other
followed an S-scheme transfer mode between Bi2WO6 and NbSe2.
To impart high specificity for efavirenz detection, a nucleotide probe was designed
using in-silico and molecular docking approaches and functionalized on the
photoanode surface using Material Studio, Dmol3 calculation. The docking studies
were conducted against various potential pollutants, with the result showing that ...