Peroxymonosulfate-assisted photocatalysis by a novel Ti3C2-based heterojunction catalyst (g-C3N4/Ti3C2/MnFe2O4) for enhanced degradation of naphthalene

Given the urgency of polycyclic aromatic hydrocarbons (PAHs) remediation and a lack of recoverable efficient catalysts for advanced oxidation processes (AOPs), a novel g-C3N4/Ti3C2/MnFe2O4 (CTM) catalyst based on the co-catalyst function of Ti3C2 (MXene) was fabricated via in situ calcination and liquid surface self-assembly, employed in a peroxymonosulfate (PMS) -assisted photocatalytic system to degrade naphthalene (NAP). Almost 100% of the NAP was removed within 45 min with pseudo-first-order kinetic constants about 2.74 and 1.97 times of those in the absence of Ti3C2 or visible light, respectively, confirming the positive role of the moderate Ti3C2 and the synergism between PMS activation and photocatalysis. The effect of initial solution pH, various inorganic anions, and actual water conditions on the reaction and stability tests revealed the potential of CTM catalysts in practical applications. There existed both free radical and non-radical pathways for NAP degradation, in which singlet oxygen (1O2) was identified as the main reactive oxygen species. This study provided a promising perspective for the rational design of efficient and stable Ti3C2-based heterojunction catalysts and their application in PMS-assisted photocatalytic systems for the effective degradation of persistent organic pollutants.