Upgrading of biomass wastes to value-added
materials
has been incessantly
pursued worldwide with diverse applications, especially deploying
photocatalytic composites encompassing metal oxides with acidic and
carbon compounds. Herein, the fabrication of a morphologically unique
acidic catalyst encompassing a two-dimensional (2D) TiO2/g-C3N4 heterojunction feature is described
for the generation of 5-hydroxymethylfurfural (5-HMF), which exploits
the acidic/ionic liquid (IL) bifunctional photocatalysis under visible
light. The structural integrity of the synthesized TiO2/g-C3N4/SO3H(IL) was corroborated
by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction
(XRD), energy-dispersive X-ray spectroscopy–energy-dispersive
spectroscopy (EDX–EDS), X-ray photoelectron spectroscopy (XPS),
thermogravimetric analysis (TGA), field emission scanning electron
microscopy (FESEM), UV–vis, Tauc plots, transmission electron
microscopy (TEM), and Brunauer–Emmett–Teller–Barrett–Joyner–Halenda
(BET–BJH) analyses. Keeping environmental impact in mind, there
are compelling advantages in the development of bio-derived pathways
to access ILs from natural renewable resources. The outcomes of environmental
assessments have revealed that the incorporation of TiO2 in g-C3N4 and ClSO3H can reduce
the probability of recombination due to ionic charges present, therefore
enhancing the photocatalytic activity via the transformation of cellulose
and glucose to produce 5-HMF in higher yields, with the optimum conditions
being reaction in water under a blue light-emitting diode (LED), at
100 °C, for 1–1.5 h. The main advantages of this production
method include minimum number of synthetic steps as well as ample
availability of and easy access to primary ingredients. While a significant
volume of 5-HMF was produced under blue light-emitting diode (LED)
radiation, the selectivity was drastically reduced in the dark. The
salient attributes of the catalyst comprise stability in air, robustness,
reusability, and its overall superior activity that is devoid of hazardous
additives or agents. This inimitable method has uncovered a newer
strategy for enhancing the photocatalytic attributes of deployed semiconducting
materials for numerous photocatalytic functions while adhering to
the tenets of environmental friendliness.