A n-butanol gas sensor with enhanced gas sensing performance based on Co-doped BiVO4 polyhedrons

N-butanol, a poisonous and flammable liquid, has great threat to human life and property security, which is of importance to monitor n-butanol in the environment. In this paper, the pure and Co-doped BiVO4 polyhedrons are successfully synthesized by hydrothermal method. A series of characterizations, such as XRD, XPS, SEM, UV, and EIS, etc., are used to analyze the crystal structure, morphology, element compositions, optical and electrochemical properties of the as-prepared samples. The optimal sample (3Co-BiVO4) exhibits high gas response (51.65) toward 100 ppm n-butanol, which is around four times higher than that of pure BiVO4 at 300 degrees C. In addition, the 3Co-BiVO4 also has fast response-recovery time, good humidity resistance, favorable selectivity to n-butanol, etc. Based on the above characterizations and gas sensing test results, the enhanced gas sensing mechanism for 3Co-BiVO4 is proposed. This work provides a feasible strategy to fabricate BiVO4 polyhedron by doping Co to greatly enhance the gas sensing properties for n-butanol.