Facile construction of a novel NiFe2O4@P-doped g-C3N4 nanocomposite with enhanced visiblelight-driven photocatalytic activity

Construction of a Z-scheme-based photocatalyst, i. e., NiFe2O4@ P-g-C3N4 nanocomposite, was successfully fabricated by coupling phosphorus-doped g-C3N4 with spinel structure NiFe2O4. The structural, morphological, and spectroscopic data of the as-synthesized photocatalyst was successfully characterized through XRD, FTIR, SEM, TEM, UV-Vis DRS, PL, and XPS techniques. It was found that NiFe2O4@ P-g-C3N4 had an increased light-absorption capacity, high exciton separation, low photogenerated electron-hole recombination, and showed better photocatalytic activity toward phenol oxidation and hydrogen energy production than the neat materials. Photocatalytic phenol oxidation by 20 wt% NFO@ P-CN was also superior and could achieve a 96% conversion, which was 2 and 3 times higher than that by P-CN and NFO, respectively. The 20 wt% NFO@ P-CN showed excellent photostability and was able to evolve 904 mmol h(-1) H-2 under visible-light irradiation. The enhanced photocatalytic activity of NiFe2O4@ P-g-C3N4 was in good agreement with the photocurrent results. The synergistic effect between P-CN and NFO could accelerate photogenerated charge separation and, moreover, the distinctive magnetism of NiFe2O4@ P-g-C3N4 aided the collection and recycling of the photocatalyst.