Design two-in-one n-MoS2/p-Cu2S heterostructures for SERS monitoring and catalytic eliminating wastewater

Monitoring toxic organic pollutants from water to protect the ecology of water resources is an important and challenging task. For this purpose, snowflake-like n-MoS2/p-Cu2S heterostructures with sensitivity and stability were synthesized by a simple method. The enhancement factor (EF) of 0.02MoS2/Cu2S substrate can reach 1.27 × 109 and limit of detection (LOD) is 10−12 M for methylene blue (MB) in lake water. Moreover, the 0.02MoS2/Cu2S showed excellent photocatalytic activity for degradation of organic pollutants (MB, CV, MG, R6G) which were removed with efficiencies of at least 70–99% within 24 min. This significant EF and photocatalytic performance are mainly attributed to the more "hot spots" offered by the distinctive morphology of Cu2S (confirmed by finite-difference time-domain (FDTD) simulation) and the increased charge-separation efficacy of p-n heterojunction owing to the 0.02MoS2/Cu2S. This study opens up new frontiers for the high-sensitivity detection and complete degradation of organic pollutants. The application of 0.02MoS2/Cu2S heterostructures to pollution problems provides a cost-effective solution for wastewater treatment.