Surfactant-Assisted Assembly of Hierarchical CdS-Ti3C2Tx MXene toward Enhanced Cooperative Photoredox Catalysis

Abstract

The scarcity of strategies to finely modulate the interface assembly between MXene and semiconductors often restricts their full potential for photocatalysis. Herein, resorting to the cetyltrimethylammonium bromide (CTAB) surfactant intercalation effect, we report the rational synthesis of hierarchical seaurchin-like CdS-Ti₃C₂T_x MXene-CTAB (CdS-T-C) ensembles to modulate the interface and structure of MXene-semiconductor heterojunctions for significantly boosted photoredox coupling catalysis. The ternary CdS-T-C exhibits markedly enhanced activity toward visible light photoreforming of benzyl alcohol (BA) to benzaldehyde (BAD) and H₂ cooperatively, as compared to bare CdS and conventional CdS-Ti₃C₂T_x MXene (CdS-T) that suffer from serious MXene restacking with obvious electronic and optical property attenuation. Mechanistic studies reveal that the CTAB interfacial intercalation alleviates the restacking of Ti₃C₂T_x, thus weakening the light shielding effect while promoting the charge transport and surface activity of MXene. This work demonstrates an appealing strategy to regulate the interfacial cross-coupling configuration of MXene-semiconductor composites for efficient solar-to-chemical conversion.