Search

[Display omitted] • Magnesiothermic reduction for the synthesis of N -deficient-g-C 3 N 4 (DCN). • Enhanced visible-light-driven photocatalytic RhB degradation. • The catalytic efficiency of DCN is almost six times higher than that of bulk g-C 3 N 4. • Providing mechanistic insights into RhB degradation over DCN catalyst. The N -deficient g-C 3 N 4 (DCN) materials were prepared via a magnesiothermic reduction of g-C 3 N 4 , which exhibited significantly enhanced visible-light absorption and photocatalytic performance compared to pristine g-C 3 N 4. In particular, the DCN sample with a g-C 3 N 4 :Mg mass ratio of 1:0.2 in the precursor mixture provided the most efficient RhB degradation of over 99%, nearly six-time higher than that of pure g-C 3 N 4. This is attributed to the widened visible-light absorption and efficient separation of generated charge carriers due to the presence of nitrogen vacancies in DCN. A proposed photocatalytic mechanism and the pH effect on rhodamine B photodegradation for DCN were obtained. [ABSTRACT FROM AUTHOR]

• Rapid adsorption of Rhodamine B (Rh.B) by ZIF-8 under visible light irradiation. • Blue-shifted π –π* transition of aromatic π system of Rh.B adsorbed on the ZIF-8. • ZIF-8 generated hydroxyl radicals for the degradation of organic dye under UV light. • Density functional theory coupled with spectroscopic techniques were optimized. The adsorption of Rhodamine B (Rh.B) was achieved by Zeolite imidazolate framework-8 (ZIF-8) in the dark condition, and the adsorption rate was noticeably increased under visible and UV light irradiations. According to fluorescence spectroscopic studies, ZIF-8 under UV light generated hydroxyl radicals for the effective degradation of Rh.B dyes. These featured mechanisms were systematically elucidated by investigating the zeta potentials of ZIF-8/Rh.B; blue-shifted π –π* transition of aromatic system; chemical shift of 13C NMR spectra; FTIR spectra; and high surface area and abundant mesopores of ZIF-8. Furthermore, the interaction mechanism between Rh.B with ZIF-8 was studied using a density functional theory (DFT) coupled with a spectroscopic technique. Herein, nine ZIF-8 clusters and Rh.B molecules were optimized in aqueous solution using the polarizable continuum model to address the solvation effect. The DFT calculations suggested that π-π stacking interactions between the xanthene ring of Rh.B and the imidazole rings of ZIF-8 and electrostatic interactions between electron-deficient Zn centers and Rh.B predominantly contributed to the adsorption of Rh.B on the ZIF-8. The experimental and computations studies provide a new insight for the sophisticated design of ZIF-8 nanostructures for removing organic pollutants efficiently through the combined adsorption and degradation under solar light irradiation. [ABSTRACT FROM AUTHOR]