Low-temperature molten salt synthesis of Na, K-codoped g-C3N4 Fenton-like catalyst with remarkable TCH degradation performance in a wide pH range

Abstract

• Na, K-codoped g-C 3 N 4 Fenton-like catalyst were synthesized by a molten salt method. • The density of single electrons of NKCN is obviously improved. • It exhbits remarkable TCH degradation performance in a wide pH range in dark. • The O 2 − radicals are the main active species during TCH degradation in dark. A Na, K-codpoed g-C 3 N 4 Fenton-like catalyst (NKCN) was prepared by a low-temperature molten salt method at 300 °C in KNO 3 -NaNO 2 system for the first time. The density of single electrons of NKCN is obviously improved by doping Na + and K + as well as the formation of more N vacancies. This NKCN material can efficiently activate H 2 O 2 to generate O 2 − radicals, which can efficiently degrade tetracycline hydrochloride (TCH, a typical emerging aqueous pollutant) in a wide pH value range (4.04–9.22) in dark. Its rate constant ( k ) is 52 and 8.7 times those of g-C 3 N 4 and Fe 2 O 3 , respectively.