Honeycomb-like carbon nitride through supramolecular preorganization of monomers for high photocatalytic performanceunder visible light irradiation

摘要

A metal-free modified carbon nitride MCU(DMSO)-C3N4 (3:3:1) with a honeycomb-like morphology was prepared via firstly introducing cyanuric acid and urea into melamine in dimethyl sulfoxide (DMSO) as the precursor for the MCU-C3N4. A variety of characterization methods, including XRD, XPS, FT-IR, SEM, TEM, UV-vis, photoluminescence (PL), and photocurrent generation, were applied to investigate the structure, morphology, optical, and photoelectrochemical properties of the g-C3N4 and MCU-C3N4 (3:3:1). Rhodamine B (RhB), methylene blue (MB), and bisphenol A (BPA) were selected as target pollutants to evaluate photocatalytic activity of the MCU-C3N4 (3:3:1) under visible light irradiation. MCU-C3N4 (3:3:1) exhibits significantly enhanced photocatalytic activity compared with g-C3N4, where 99.49% RhB is removed within 40min, 97.7% MB is removed within 80 min, and 84.37% BPA is removed within 90 min. The improved photodegradation efficiency was mainly due to the larger surface area, the stronger REDOX ability, and the increased separation efficiency of photogenerated electron-hole pairs. The active radical trapping experiments and electron spin resonance tests indicated that h(+) and center dot O-2(-) radicals were the dominant active species whereas center dot OH radicals could be a minor factor. A possible photocatalytic mechanism is proposed. This strategy here provides an ideal platform for the design of photocatalysts with large surface area and high porosity for various pollutant controlling applications. (C) 2018 Elsevier Ltd. All rights reserved.