Construction of Cu2O@Cu1.75S Core-shell Octahedrons for Enhanced NO2 Gas Sensing at Low Temperature

In this work, fabrication of Cu 2 O@Cu 1.75 S core-shell octahedrons was achieved through a facile water bath stirring process. Compared with pure Cu 2 O, the composite showed enhanced sensing performance for NO 2 . The response value of Cu 2 O@Cu 1.75 S to 5 ppm NO 2 at 40 °C is seven times that of Cu 2 O to 5 ppm NO 2 at 75 °C. Moreover, Cu 2 O@Cu 1.75 S has the ability to detect 100 ppb NO 2 and has good NO 2 sensing selectivity and long-term stability. This study shows that Cu 2 O@Cu 1.75 S hybrid is a type of outstanding NO 2 gas sensing material on account of its low working temperature and high sensing sensitivity.