An oxygen vacancy-engineered Bi2MoO6 light collector with prominent SERS enhancement for ultrasensitive detection and degradation of organic contaminants

Abstract

Surface-enhanced Raman scattering (SERS) based on the chemical mechanism (CM) has attracted tremendous attention for high stability and reproducibility. However, effectively improving the sensitivity of CM-based SERS remains a challenge. Herein, an oxygen vacancy-engineered bismuth molybdate (Bi2MoO6) light collector with superior SERS sensitivity and high reproducibility was developed as CM enhancing substrate. The Raman enhancement factor (EF) was calculated to be 2.7 × 107, resulting in an ultra-low limit of detection (LOD) for methyl orange (MO) down to 1.92 × 10−11 M. The remarkable SERS enhancement was ascribed to the synergistic effect of oxygen vacancy-promoted photoinduced charge transfer (PICT), enhanced light-harvesting ability, and molecule enrichment through cavity-like micro/nanostructures. Moreover, the PICT line contributed to effective charge separation, which resulted in enhanced photocatalytic activity of the Bi2MoO6 substrate for self-cleaning utilization. The dual-functional substrate presented excellent SERS activity and recyclability in the SERS detection of organic contaminants in wastewater samples. The oxygen vacancy-engineered Bi2MoO6 light collector provides new insight for rational CM-based SERS substrate design and opportunities for developing recyclable SERS substrates and extending applications of semiconductor-based SERS.