Nitrogen vacancy modulated amorphization and photoluminescence in graphitic carbon nitride under pressure

Abstract

The bandgap engineering in graphitic carbon nitride (g-C3N4) has attracted much attention in the aim to optimize its photoelectric properties. Amorphization shows potential advantages in modulating the bandgap of various semiconductors. In this report, we propose a collaborative strategy that combines pressure treatment and introducing vacancies to fabricate amorphized g-C3N4 with tunable photoluminescence (PL) wavelength. An irreversible pressure-induced amorphization occurs at ∼25 GPa for pristine g-C3N4, which retains upon decompression to ambient conditions. Through increasing amount of N vacancy, the transition pressure of amorphization decreases accompanied by tunable PL central wavelength from 581 to 640 nm at ambient conditions, while introducing N vacancies alone shifts the PL only from 560 to 619 nm. The collaborative method of pressure technology and introducing vacancies can manually prepare various amorphized materials and enhance the visible-light absorption ability.