Efficient synthesis of polymeric g-C3N4 layered materials as novel efficient visible light driven photocatalysts

TLDR

The study aims to create high‑surface‑area polymeric g‑C3N4 layered photocatalysts by directly heating urea in air between 450–600 °C, avoiding templates, to achieve efficient visible‑light activity for environmental applications. The authors synthesize the g‑C3N4 materials by a single‑step, template‑free thermal treatment of urea in air at 450–600 °C, yielding layered structures with high surface area. The resulting g‑C3N4 materials exhibit a 2.7 eV band gap, increased crystallinity and surface area with higher temperatures, and outperform C‑doped TiO₂ and dicyanamide‑derived g‑C3N4 in RhB photodegradation, demonstrating superior visible‑light photocatalytic activity suitable for large‑scale environmental remediation and solar energy conversion.

Abstract

In order to develop efficient visible light driven photocatalysts for environmental applications, novel polymeric g-C3N4 layered materials with high surface areas are synthesized efficiently from an oxygen-containing precursor by directly treating urea in air between 450 and 600 °C, without the assistance of a template for the first time. The as-prepared g-C3N4 materials with strong visible light absorption have a band gap around 2.7 eV. The crystallinity and specific surface areas of g-C3N4 increases simultaneously when the heating temperatures increases. The g-C3N4 materials are demonstrated to exhibit much higher visible light photocatalytic activity than that of C-doped TiO2 and g-C3N4 prepared from dicyanamide for the degradation of aqueous RhB. The large surface areas, layered structure and band structure in all contributed to the efficient visible light photocatalytic activity. The efficient synthesis method for g-C3N4 combined with efficient photocatalytic activity is of significant interest for environmental pollutants degradation and solar energy conversion in large scale applications.