Gaseous Mercury Capture by Copper-Activated Nanoporous Carbon Nitride

Abstract

Graphitic carbon nitride (g-C3N4) as a 2D layered carbon material with exceptional electronic, thermal, and catalytic property has attracted increasing research attention. A porous g-C3N4 nanosheet (PCNN) has been synthesized via a facile two-step thermal etching oxidation approach and applied in low-temperature elemental mercury (Hg0) removal. PCNN exhibits good reactivity toward Hg0 adsorption at temperatures of 40–200 °C. CuO impregnation can prominently enhance the Hg0 capture performance of PCNN on account of the intimate interaction of CuO and PCNN. Temperature has a positive effect on Hg0 capture ability of PCNN and CuO/PCNN. Hg0 is mainly oxidized by the chemisorbed oxygen species that are generated from the O–C–N of g-C3N4 and the lattice oxygen of CuO. CuO modification can efficiently activate g-C3N4 with significantly improved Hg0 capture ability presumably owing to the Mott–Schottky effect at the interface of CuO and g-C3N4.