High performance magnetically recoverable g-C3N4/Fe3O4/Ag/Ag2SO3 plasmonic photocatalyst for enhanced photocatalytic degradation of water pollutants

•Preparation of novel g-C3N4/Fe3O4/Ag/Ag2SO3 plasmonic photocatalyst is reported.•Activity of g-C3N4/Fe3O4/Ag/Ag2SO3 (40%) nanocomposite is 11.7-folds of g-C3N4.•The nanocomposite is simply separated from the treated solution using a magnet.•The nanocomposite has excellent stability even after five degradation runs.

The g-C3N4/Fe3O4/Ag/Ag2SO3 nanocomposites have been successfully fabricated by facile refluxing method. The as-obtained products were characterized by XRD, EDX, SEM, TEM, UV-vis DRS, FT-IR, TGA, PL, and VSM techniques. The results suggest that the Ag/Ag2SO3 nanoparticles have anchored on the surface of g-C3N4/Fe3O4 nanocomposite, showing strong absorption in the visible region. The evaluation of photocatalytic activity indicates that for the g-C3N4/Fe3O4/Ag/Ag2SO3 (40%) nanocomposite, the degradation rate constant was 188 × 10−4 min−1 for rhodamine B, exceeding those of the g-C3N4 (16.0 × 10−4 min−1) and g-C3N4/Fe3O4 (20.2 × 10−4 min−1) by factors of 11.7 and 9.3, respectively. The results showed that the nanocomposite prepared by refluxing for 120 min has the superior photocatalytic activity and its activity decreased with rising the calcination temperature. The trapping experiments confirmed that superoxide ion radical was the main active species in the photocatalytic degradation process. Also, it was demonstrated that the magnetic photocatalyst has considerable activity in degradation of one more dye pollutant. Finally, the reusability of the photocatalyst was evaluated by five consecutive catalytic runs. This work may open up new insights into the utilization of magnetically separable nanocomposites and provide new opportunities for facile fabrication of g-C3N4-based plasmonic photocatalysts.

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