Fluorine functionalized graphitic carbon nitride for cataluminescence sensing of H2S

Graphitic carbon nitride, as an excellent metal-free catalyst, is a promising candidate for cataluminescence (CTL) sensing of H 2 S owing to its high sulfur tolerance, environmental friendliness and low cost. Herein, in view of inner chemical inertness and low special surface area of g-C 3 N 4 , fluorine with strong electronegativity was employed to adjust the electron density of g-C 3 N 4 to obtain fluorine functionalized graphitic carbon nitride (F-g-C 3 N 4 ) for H 2 S sensing. As expected, the CTL response of F-g-C 3 N 4 exhibits more than 30 times higher towards H 2 S by contrast with that of g-C 3 N 4 . Results demonstrated that F-g-C 3 N 4 was more conducive to the adsorption of O 2 and H 2 S due to the enlarged special surface area, the easier formation of hydrogen bond and the changed electronic structure, which was also supported by density functional theory calculations. Additionally, the F-g-C 3 N 4 -based sensor exhibits as high sensitivity as that of metal catalyst-based sensors but a longer lifetime. Meanwhile, the F-g-C 3 N 4 -based sensor has much higher CTL responses in the range of 1.27∼64.00 μg mL −1 , lower detection limit of 0.07 μg mL −1 when comparing with previously reported metal-free catalyst-based sensors. Undoubtedly, this work not only opened up a novel approach to improve the sensing performance of g-C 3 N 4 , but also proposed an efficient strategy for obtaining satisfying catalytic performance of other metal-free layered materials.