Designed fabrication of sulfide-rich bi-metallic-assembled MXene layered sheets with dramatically enhanced photocatalytic performance for Rhodamine B removal

Abstract

Herein, a two-step hydrothermal treatment was used to synthesize a novel hybrid photocatalyst with sulfide-rich layered double hydroxides intercalated MXene for the degradation of rhodamine B (RhB). The fabricated NiCo2S4 on MXene (denoted as NCS@MX) photocatalyst showed higher catalytic activity and degraded RhB to approximately ≈100% within 20 min under visible light irradiation. The optical response and recombination rate used increased the separation efficiency of photoinduced e− and h+ by NCS@MX, thus enhancing the photocatalytic degradation of RhB. The OH and O2− radicals were non-toxic by-products of the NCS@MX system for the mineralization of organic pollutants. Furthermore, NCS@MX exhibited great photo-stability in five repetitive runs for the degradation of RhB with a minimal drop on catalytic activity. Possible oxidative pathways of RhB and the reaction intermediates were observed by liquid chromatography-mass spectrometry (LC-MS). The pollutant was primarily oxidized into non-toxic products such as H2O, CO2, and few inorganic species. Therefore, NCS@MX is expected to have prospects for applications in wastewater management considering its environmental friendliness, low-cost, and non-toxic by-products production.