Reduced graphene oxide (RGO)-supported
bismuth ferrite (BiFeO3) (RGO–BFO) nanocomposite
is synthesized via a two-step
chemical route for photoelectrochemical (PEC) water splitting and
photocatalytic dye degradation. The detailed structural analysis,
chemical coupling, and morphology of BFO- and RGO-supported BFO are
established through X-ray diffraction, Raman and X-ray photoelectron
spectroscopy, and high-resolution transmission electron microscopy
studies. The modified band structure in RGO–BFO is obtained
from the UV–vis spectroscopy study and supported by density
functional theory (DFT). The photocatalytic degradation of Rhodamine
B dye achieved under 120 min visible-light illumination is 94% by
the RGO–BFO composite with a degradation rate of 1.86 ×
10–2 min–1, which is 3.8 times
faster than the BFO nanoparticles. The chemical oxygen demand (COD)
study further confirmed the mineralization of an organic dye in presence
of the RGO–BFO catalyst. The RGO–BFO composite shows
excellent PEC performance toward water splitting, with a photocurrent
density of 10.2 mA·cm–2, a solar-to-hydrogen
conversion efficiency of 3.3%, and a hole injection efficiency of
98% at 1 V (vs Ag/AgCl). The enhanced catalytic activity of RGO–BFO
is explained on the basis of the modified band structure and chemical
coupling between BFO and RGO, leading to the fast charge transport
through the interfacial layers, hindering the recombination of the
photogenerated electron–hole pair and ensuring the availability
of free charge carriers to assist the catalytic activity.