▎ 摘　　要

A crumpled graphene oxide-SnO2 nanocolumn (CGO-SnO2) composite electrode was fabricated using aerosol-based techniques. First, SnO2 nanocolumn thin films were fabricated using an aerosol chemical vapor deposition (ACVD) technique. The surface of the nanocolumn was then decorated with CGO by electrospray deposition. The CGOSnO(2) electrode was utilized for the electrochemical detection and determination of the free chlorine concentration in aqueous solutions using linear sweep voltammetry (LSV) and amperometric i-t curve techniques. The CGO-SnO2 electrodes worked through the direct electrochemical reduction of hypochlorite ions (ClO-) on the surface of the electrode, which was used to determine the free chlorine concentration. The electrodes operate over a wide linear range of 0.1-10.08 ppm, with a sensitivity of 2.69 mu A mu M-1 cm(-2). Further, selectivity studies showed that these electrodes easily conquer the electrochemical signals of other common ions in drinking water distribution systems, and only shows the electrochemical reduction signals of free chlorine. Finally, the CGO-SnO2 electrodes were successfully employed for the detection of free chlorine in tap water solutions (St. Louis, MO 63130, USA) with a sensitivity of 5.86 mu A mu M-1 cm(-2). Overall, the sensor fabricated using simple and scalable aerosol-based techniques showed a comparable performance to previous studies on amperometric chlorine sensing using carbonbased electrodes.