Interfacial coupling effects in a-Fe2O3/g-C3N4 composite magnetically separable heterojunction with upgraded Z-scheme photocatalytic performance of mixed organic pollutant degradation

Photocatalysis has fascinated wide consideration due to its promising advantage in wastewater treatment. And the metal-oxides and g-C3N4 that possess Z-scheme heterojunctions have become the energetic photocatalysts (PCs) in degrading the organic impurities. In this work, a novel magnetic separable g-C3N4/-Fe2O3 (GFE) nanocomposites (NCs) were fabricated by a facile hydrothermal strategy. Structural, morphological, optical, surface area and magnetic belongings of GFE composites were effectively explored using XRD, FT-IR, XPS, FESEM, HRTEM with EDX mapping, BET, UV-DRS and PL spectra. The (g-C3N4/20 wt % alpha-Fe2O3) GFE2 com-posite PCs were verified robust with significantly upgraded the photocatalytic efficiency for (anionic) RhB (97.2%) and (cationic) MB (90.6%) mixed aqueous organic pollutants degradation in 150 min under visible-light exposure, which was favourably higher than to GCN (65.2%) and alpha-Fe2O3 (16.6%) PCs. Moreover, the as-obtained GFE composite PCs also exposed great stability after five successive recyclabilities. The enhanced photo-degradation activity was largely ascribed to the extended visible-light fascination ability, high surface area, augmented active sites and strong redox ability relatively. Also, the energetic formation of alpha-Fe2O3 coupled g-C3N4 heterojunction that skilled the probable recombination rate and beneficial for the separation of photo-excited electron and hole (e(-)/h(+)) pairs based on active Z-scheme mechanism was liable for eliminating organic mixed pollutants.

Automated summary

Photocatalysis has been widely studied for its promising benefits in wastewater treatment. Metal-oxides and g-C3N4 with Z-scheme heterojunctions have become energetic photocatalysts in degrading organic impurities. In this study, a novel magnetic separable g-C3N4/-Fe2O3 nanocomposites were fabricated using a facile hydrothermal strategy. The composites showed enhanced photocatalytic efficiency in degrading RhB and MB mixed aqueous organic pollutants under visible-light exposure, and exhibited good stability after multiple recyclabilities. The enhanced photo-degradation activity was attributed to the extended visible-light absorption ability, high surface area, increased active sites, and strong redox ability of the composites. The active heterojunction formed by alpha-Fe2O3 and g-C3N4 played a crucial role in preventing the recombination of electrons and holes, promoting the separation of photo-excited electron and hole pairs, and eliminating organic mixed pollutants.