Oxygen vacancies enabled hierarchical SnO2 for highly sensitive Cl2 detection at room temperature

Chlorine (Cl2) is a highly hazardous and corrosive substance that can cause severe respiratory problems and skin burns in humans at low doses. The effective detection of Cl2 has become critical for protecting both the ecological environment and public health. Herein, the oxygen vacancy-abundant SnO2 were synthesized using SnS as template followed by the calcination method. The resultant SnO2-800 sensor exhibits improved sensing response to Cl2 (about 205-10 ppm) at room temperature, together with a trace detection limit of 100 ppb. Such excellent sensing properties could be assigned to several reasons including the unique cross-linked structure, the appropriate amount of grain boundaries, and especially sufficient oxygen vacancies. The XPS, GC-MS techniques and DFT theoretical calculation were combined used to detailly investigate the sensing mechanism. This work might shed light on the rational design of high-performance sensing materials via defect engineering.