Supramolecularly engineered S-scheme SubPc-Br/MoS2 photocatalyst nanosheets for enhanced photocatalytic degradation of antibiotics

Abstract

Developing a simple, low-cost, high-yield, and controllable strategy for preparing various functionalized MoS2-based composite materials remains a challenge. This study innovatively utilizes boron subphthalocyanine bromide (SubPc-Br) as a photosensitizer, which self-assembles on MoS2 via intermolecular π-π stacking, creating a SubPc-Br/MoS2 organic–inorganic semiconductor system. This addresses a research gap, employing subphthalocyanines as MoS2 sensitizers. The SubPc-Br/MoS2 heterojunction exhibited excellent photocatalytic activity for the degradation of antibiotics in water under solar irradiation. The rate constants for the photocatalytic degradation of CTC and CIP by SubPc-Br/MoS2 were 4.66 and 5.93 times higher than those of pristine MoS2, respectively. The significant improvement in photocatalytic performance is attributed to the efficient charge separation and transfer induced by the unique S-Scheme charge transfer mechanism, which has been verified by different theoretical and experimental results. We demonstrate that the photochemical activity of O2 molecules adsorbed on MoS2(100) is site-sensitive, with O2 preferentially adsorbing on the Mid-site location with higher electron transport capability. This study provides a new perspective for enhancing photocatalytic performance by constructing an artificial photosynthetic system with an S-scheme heterojunction.