One step to prepare Cl doped porous defect modified g-C₃N₄ with improved visible-light photocatalytic performance for H₂ production and rhodamine B degradation

Cl doped porous defect modified graphitic carbon nitride (Cl-pdg-C₃N₄) have been synthesized by pyrolysis of the mixture of melamine and NH₄Cl, and thoroughly analyzed by x-ray diffraction, Fourier transform infrared spectroscopy, x-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, N₂ adsorption-desorption isotherm, BET, UV–vis diffuse reflectance spectra, photoluminescence spectra and photoelectrochemical properties. Experimental results indicated that Cl in NH₄Cl could react with melamine to form supermolecule to induce the formation of porous structure. Meanwhile, NH₄Cl could occupy space to limit the long-range polymerization of g-C₃N₄, resulting in the formation of N defect. Moreover, NH₄Cl as the Cl element precursor could induce Cl element doped in the g-C₃N₄ system. When Cl-pdg-C₃N₄ worked as photocatalyst for producing H₂ and degrading rhodamine B under visible light, the as-prepared Cl-pdg-C₃N₄ presented more excellent photocatalytic activity and kept excellent recycled activity than bulk g-C₃N₄. Hence, this strategy provides insights into the fabrication of g-C₃N₄ with excellent photocatalytic activity, which was promisingly applied in various fields. (paper)