Synthesis, characterization, and photocatalytic performance of Ag/AgFeO2 decorated on g-C3N4-nanosheet under the visible light irradiation

Abstract

In this work, the CNNS/Ag/AgFeO2 photocatalysts were synthesized by the thermal polymerization-hydrothermal method, aiming for photocatalytic degradation of RhB under visible irradiation. Different advanced techniques such as X-ray diffraction analysis (XRD), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS), Total Organic Carbon (TOC) analysis, and so on were employed to examine samples features. The results showed that the CNNS/Ag/AgFeO2 (15%) photocatalyst possess a higher potential for rhodamine B (RhB) photodegradation than pure CN and CNNS photocatalysts. The rate constant of CNNS/Ag/AgFeO2 (15%) (957×10–4 min−1) is 55 and 5.8 times higher than of pure CN (17.3 × 10–4 min−1) and CNNS (164×10–4 min−1) photocatalysts, respectively. The reasons for the better photocatalytic performance of prepared nanocomposites can be attributed to the synergistic effect between CNNS and Ag/AgFeO2. Therefore, the ability of visible light absorption and separation of photogenerated electron-hole pairs are effectively increased. A photocatalytic mechanism was presented, and suppressing the recombination of photogenerated charges resulting from the formation of the Z-scheme heterojunction was discussed. The prepared nanocomposite's photocatalytic performance for malachite green (MG), methyl orange (MO), and congo red (CR) degradation as organic dyes and phenol as a colorless pollutant were studied. Besides, after four photocatalytic cycles, there was no significant inactivity, indicating acceptable stability of the investigated nanocomposite.