In the present study, superhydrophobic magnetic spiky nickel nanowires were fabricated using a one-pot hydrothermal process and grafted with octadecyltrichlorosilane (ODTS) coupling agent. In a systematic investigation, the effects of ODTS concentration, sonication time, and modifying solution volume on the surface wettability of the samples have been investigated. XRD, FTIR, FESEM, EDS, XPS, and VSM analyses were conducted to confirm the self-assembled monolayer deposition of silane coupling agent and evaluating the morphological and chemical features of the produced sample before and after surface modification. Superhydrophobicity analysis of the magnetic spiky nickel nanowires grafted with ODTS coupling agent indicated that the water contact angle (WCA) and the contact angle hysteresis (CAH) values were 167.34 ± 1.23° and 1.29 ± 0.9°, respectively achieved under the best-operating conditions including ODTS concentration of 12.5 mM, reaction time of 60 min, and ODTS/toluene solution volume of 10 mL. The prepared spiky nickel nanowires were soaked in various pH value adjusted media ranging from 2 to 12 for 24, 48, 72, 96, and 120 h. Results indicated excellent chemical stability of the wetting properties (WCA>150° and CAH<10°). Also, gravity-driven dichloromethane and chloroform/water mixture separation were conducted using superhydrophobic layered-spiky nickel nanowires, which showed efficient fluxes of 5203.43±22 and 4327.25±41 L m−2 h−1, respectively. The modified sample also showed good reusability after twenty oil/water separation cycles, highlighting the prepared nanospiky materials for industrial applications.