Enhancement of photocatalytic efficiency of Fe2O3 through g-C3N4 nanosheet modification for degradation of organic and pharmaceutical pollutants and hydrogen production.

In this paper, a Fe 2 O 3 /g-C 3 N 4 nanocomposite was prepared using a facile precipitation method, demonstrating the influence of g-C 3 N 4 nanosheets on the photocatalytic efficiency of α-Fe 2 O 3. Despite the stability of pure g-C 3 N 4 during heat treatment up to 700 °C, its presence, along with iron oxide during calcination, reduces its stability temperature to about 450 °C. The reduction of hematite to magnetite by carbon is accompanied by the decomposition of g-C 3 N 4. The appropriate calcination temperature determined for this synthesis process is 390 °C. Microscopic analysis revealed a uniform distribution of α-Fe 2 O 3 particles (average particle size of 16 nm) on g-C 3 N 4 nanosheets with a close and intimate contact. The g-C 3 N 4 content in the nanocomposite influenced the size of Fe 2 O 3 nanoparticles. g-C 3 N 4 nanosheets in the α-Fe 2 O 3 structure changed the band gap from 1.9 to 2.4 eV, reducing the recombination rate of electrons and holes. A nanocomposite containing 10 wt% g-C 3 N 4 showed the highest photocatalytic performance. The Z-scheme charge transfer mechanism and the significant role of superoxide radicals in the photocatalytic process were identified. The nanocomposite's photocatalytic efficiency was evaluated on various pollutants, including methylene blue (MB, 88 %), phenol (60 %), methyl orange (MO, 38 %), and the pharmaceutical compound Metformin (96 %). The α-Fe 2 O 3 /10 wt% g-C 3 N 4 nanocomposite exhibited the highest hydrogen production rate at 435 μmol/g.h, establishing its importance in photocatalytic performance. [ABSTRACT FROM AUTHOR]