Highly ordered mesoporous V2O5 nanospheres utilized chemiresistive sensors for selective detection of xylene

[Display omitted] •A template-free solvothermal method demonstrated for hollow V2O5 nanospheres.•Sensor displays good response, repeatability and long-term stability towards xylene.•Superior xylene selectivity against other interfering gases is observed.•The sensing mechanism of V2O5 nanospheres towards xylene is deduced in detail. This work reports a simple, time efficient, template-free solvothermal and environmentally friendly method for the synthesis of V2O5 nanospheres (NSs) for xylene gas detection. The four types of V2O5-5, V2O5-7, V2O5-9 and V2O5-11 NSs have been synthesized and tested toward xylene in concentration ranging from 1 ppm to 300 ppm. The V2O5-7 sensor exhibits excellent sensing response of 2.75 toward 100 ppm xylene gas within fast response time of 21 s with obtained limit of detection (LOD) of 1 ppm at optimal operating temperature 290 °C. The sensing mechanism is based on an interaction of V2O5 NSs towards xylene through chemical reaction with adsorbed oxygen species present on V2O5 NSs, resulting in a thinner depletion layer and a lower potential barrier which further leads to decrease in sensor resistance. These experimental results suggest that the V2O5 NSs based sensors have potential to fulfill the demands in the gas sensing field.