Surface structural transformation and adsorption performance of poly(triazine imide)

Poly(triazine imide) synthesized by the molten salt route with incorporation of Li+ and Cl- ions (PTI/Li+Cl-) was prepared by rational controlling of the washing extent. The surface transformation of the phase-pure PTI framework incurred by thorough washing has been confirmed by a systematic analysis based on x-ray diffraction, Ultraviolet Raman, atomic force microscope, and x-ray photoelectron spectroscopy measurements. Uranyl ion adsorption experiments further support the surface structural transformation from triazine-unit PTI to heptazine-based graphitic carbon nitride. Efforts on the exploration of PTI material application should be mainly directed toward the waterless fields to give good repeatability. Graphical Abstract The surface transformation of the phase-pure PTI/LiCl from triazine-based structure to heptazine-based g-C3N4 framwork incurred by thorough washing has been detected by a systematic analysis based on XRD, Ultraviolet Raman, AFM and XPS measurements, and further confirmed by uranyl ion adsorption experiments.