Free-standing Ni(OH)(2) platelet-like nanostructures with average width of 124 nm and thickness of 19 nm were successfully prepared through a simple one-pot polymer assisted process. The preparation involves the assistance of poly (sodium-4-styrene sulfonate) (PSS) and is easy to perform. The influence of pH value on the structure of the Ni(OH)(2) product was investigated and it was found that pH value plays an important role for the formation of free-standing Ni(OH)(2) nanoplatelets. A possible formation mechanism is proposed. In addition, from the obtained Ni(OH)(2) nanoplatelets, a NiO sensor was fabricated and tested, which exhibits a 5 ppm sensing sensitivity to ethanol and propanol. (C) 2013 Elsevier Inc. All rights reserved.