Efficient Charge Transfer in TiOPc/MoS₂ Heterostructure for Dynamically Enhanced SERS Sensing and Photocatalysis

Surface-enhanced Raman scattering (SERS) offers exceptional sensitivity for trace contaminant detection; conventional noble-metal substrates suffer from high cost, signal irreproducibility, and poor chemical stability. While semiconductor alternatives are promising, their performance is fundamentally limited by sluggish interfacial charge-transfer kinetics under static band alignment. To overcome these limitations, we introduced a new strategy centred on a high carrier generation rate (HCGR). By integrating TiOPc, a material that exhibits strong Ti-O bond polarisation and a high HCGR, with atomically thin MoS₂, we constructed a hybrid platform that drives efficient charge transfer via HCGR-enabled kinetic pumping, surpassing traditional thermodynamic band engineering. This HCGR-driven efficient CT mechanism primarily amplifies SERS through enhanced chemical mechanisms (CM) with minor electromagnetic contributions, achieving an enhancement factor (EF) of 10⁷. The platform can detect methylene blue (MB) and rhodamine 6G (R6G) at concentrations as low as 10^-14 M and 10^-13 M, respectively, demonstrating excellent repeatability (RSD = 7.2%) and stability over 60 days. Additionally, efficient CT accelerated MB photodegradation under UV light, achieving complete decomposition within 80 min. The practical applicability of the platform is evidenced by detecting Hg²⁺ (LOD: 10^-11 M) and malachite green in tap/lake water (LODs: 10^-12 M/10^-10 M). This work establishes HCGR-driven efficient CT as the next generation of semiconductor SERS platforms. It provides a scalable route toward low-cost, reusable sensors for real-time, in situ monitoring of industrial effluents and the dynamic pollutant degradation of pollutants in environmental monitoring.