Enhanced visible light photocatalytic activity of CdS with alkalized Ti₃C₂ nano-sheets as co-catalyst for degradation of rhodamine B

Active co-catalysts have been extensively used for improving photocatalytic activity in semiconductor-based photocatalytic systems. Herein, 2D alkalized Ti₃C₂ (Ti₃C₂-OH) nano-sheets were coupled with CdS via a facile electrostatic self-assembly strategy and combined with hydrothermal method to prepare Ti₃C₂-OH/CdS photocatalyst. The morphologies, crystal phases, optical and photoelectrical properties of the prepared photocatalysts were characterized by XRD, SEM, TEM, FTIR, PL, and EIS analysis, respectively. The photocatalytic degradation results verified that the photo-degradation performance of Ti₃C₂-OH/CdS photocatalyst (degradation of 97% RhB in 100 min) was obviously superior to that of pure CdS (degradation of 70% RhB in 100 min) and Ti₃C₂/CdS (degradation of 82% RhB in 100 min). The active species trapping experiments for Ti₃C₂-OH/CdS photocatalyst revealed that the superoxide radical (^·O₂⁻) and holes (h⁺) were the predominant species for degradation of RhB. Furthermore, the Ti₃C₂-OH co-catalyst in the Ti₃C₂-OH/CdS composite not only played the role of promoting the effective separation of photo-generated electron–hole pairs, but also constructing strong connections with CdS semiconductor to establish heterostructure, ultimately enhancing the photocatalytic performance of the Ti₃C₂-OH/CdS photocatalyst.