A Unique, Porous C 3 N 4 Nanotube for Electrochemiluminescence with High Emission Intensity and Long-Term Stability: The Role of Calcination Atmosphere.

Developing excellent strategies to optimize the electrochemiluminescence (ECL) performance of C 3 N 4 materials remains a challenge due to the electrode passivation, causing weak and unstable light emission. A strategy of controlling the calcination atmosphere was proposed to improve the ECL performance of C 3 N 4 nanotubes. Interestingly, we found that calcination atmosphere played a key role in specific surface area, pore-size and crystallinity of C 3 N 4 nanotubes. The C 3 N 4 nanotubes prepared in the Air atmosphere (C 3 N 4 NT-Air) possess a larger specific surface area, smaller pore-size and better crystallinity, which is crucial to improve ECL properties. Therefore, more C 3 N 4 •- excitons could be produced on C 3 N 4 NT-Air, reacting with the SO 4 •- during the electrochemical reaction, which can greatly increase the ECL signal. Furthermore, when C 3 N 4 nanotube/K 2 S 2 O 8 system is proposed as a sensing platform, it offers a high sensitivity, and good selectivity for the detection of Cu 2+ , with a wide linear range of 0.25 nM~1000 nM and a low detection limit of 0.08 nM.