Highly sensitive toluene sensor based on porous core-shell-structured In2O3–ZnO nanofibers under UV irradiation at room temperature

Porous core-shell-structured In2O3–ZnO nanofibers (NFs) were synthesized using two-step method. The porous and core-shell structure of the In2O3–ZnO NFs was confirmed using field emission scanning electron microscopy and field emission transmission electron microscopy. Gas sensing experiments showed that the In2O3–ZnO NFs exhibited a response of 34.7–100 ppm of toluene gas at room temperature (RT), which was 5.5- and 6.4-fold higher than that of the pure ZnO NFs and pure In2O3 NFs, respectively. The In2O3–ZnO NFs sensor also demonstrated fast response, excellent selectivity, and long-term stability at RT. The enhanced sensing properties for toluene gas were attributed to the larger specific surface area, higher concentration of chemisorbed oxygen species, and core-shell heterostructure of the In2O3–ZnO NFs. The authors anticipate that this study will facilitate the development of future gas sensors for the detection of toluene gas at RT.