The preparation of visible light-responsive efficient
photocatalysts
for removing organic contaminants from water and killing cancer cells
has gotten a lot of attention due to the growing global concern. In
this study, we have successfully fabricated an efficient AgBr/β-MnO
2
nanocomposite via a facile deposition and precipitation method
at room temperature. Techniques such as XRD, SEM-EDS, TEM, DRS, PL,
EIS, ESR, and FTIR were used to determine the crystalline, structural,
morphological, optical, and other properties. The SEM and TEM analyses
reveal that AgBr NPs are decorated on the surface of β-MnO
2
, which possesses rods with a sphere-like structure for AgBr/β-MnO
2
. The EDX analysis confirms the existence of Mn, O, Ag, and
Br elements in the nanocomposites without an extra peak, indicating
that the synthesized samples are highly pure. The high photocatalytic
performance of AgBr/β-MnO
2
could be attributed to
the formation of Ag NPs and the construction of the Z-scheme heterojunction
between AgBr and β-MnO
2
. This may enhance fast light
absorption and efficient photogenerated (e–/h+) pairs, as indicated
by EIS and photoluminescence measurements, which in turn achieved
high activity for the decomposition of MB (97%, in 12 min), RhB (98.9%,
in 9 min), and paracetamol (80%, in 180 min), respectively. The kinetic
model study proposed that the first-order model showed a better fit
than the zero- and second-order for the photocatalytic decolorization
of RhB dye. XRD analysis of 0.2 AgBr/β-MnO
2
before
and after recycling confirms the high stability of the catalyst. HPLC
results showed that no detectable by-products are produced through
the decomposition of paracetamol. Interestingly, 0.2 AgBr/β-MnO
2
nanocomposites showed visible light-induced anticancer activity
against A549 cancer cell lines. The mechanistic degradation pathway
has been proposed using the involvement of active species like superoxide
radicals (
−•
O
2
) and photoinduced
holes (h
+
). The proposed work focuses on synthesizing effective
photocatalysts in a less hazardous environment with superior biological
activity.