An extremely small size novel adsorbent, nickel hydroxide nanoplate loaded on activated carbon (Ni(OH)(2)-NP-AC) was synthesized using a simple, low cost and highly efficient method. The developed adsorbent was used for the removal of hazardous MG dye from the aqueous solution. To evaluate the importance of Ni(OH)(2) nanoplates on the adsorption and removal process, the contact time of virgin AC and Ni(OH)(2)-NP-AC were compared (under the same conditions) that the results showed Ni(OH)(2) nanoplate had a crucial role in the removal or adsorption process. The surface unique textural and morphological properties such as high surface area (>960 m(2) g(-1)) and low pore size (<3.5 nm) made it possible for efficient and rapid removal of MG. Subsequently, the impact of various influential variables such as pH, adsorbent dosage, initial dye concentration, contact time and temperature were examined and optimized. The adsorption kinetic and equilibrium data of MG were found well fitted and found to be in good agreement with pseudo-second-order and Langmuir models, respectively. Finally, antibacterial activity of the synthesized nanoplates was evaluated by testing against some Gram-negative and Gram-positive bacteria. The results of this antibacterial testing indicated that the synthesized nanoplates showed effective bactericidal activity. (C) 2016 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.