Boosting Acetone Sensing Performance of ZnCo ₂ O ₄ Nanowire Arrays Through Surface Etching

ABSTRACT It is crucial to develop a gas sensor that is fast, efficient, and capable of real‐time monitoring of acetone. In this study, a cost‐effective and environmentally sustainable synthesis approach was employed to in situ fabricate ZnCo 2 O 4 nanowire arrays on ceramic tubes. By adjusting the etching time in NaBH 4 solution, the content of Co 2+ and oxygen species concentration in ZnCo 2 O 4 were effectively modulated. The ZnCo 2 O 4 nanowire arrays sensor etched with NaBH 4 solution for 30 min (ZCO‐30) exhibited a high response of 42.1 toward 100 ppm acetone at 130°C, a recovery time of 13 s, and a detection limit as low as 100 ppb. The sensor also demonstrated excellent reproducibility, humidity resistance, and long‐term stability. This excellent sensing performance is attributed to the unique array structure of ZnCo 2 O 4 , abundant Co 2+ , oxygen vacancies, and the content of surface‐adsorbed oxygen species.