Direct preparation of Al-substituted α-Ni(OH)2 from Al-containing salt solution by immersing method

The present study attempts to prepare Al-substituted α-Ni(OH)2 and Al-substituted α-Ni(OH)2 with modified interlayer anions by directly immersing pure α-Ni(OH)2 into AlCl3-containing solutions. XRD and FT-IR analysis demonstrated Al-substituted α-Ni(OH)2 can be prepared directly by soaking pure α-Ni(OH)2 into AlCl3 solution. Al-substituted α-Ni(OH)2 with S2O32− as the primary anion in the interlayer can be obtained by immersing pure α-Ni(OH)2 into AlCl3-Na2S2O3 solution. The analysis of Al content in samples demonstrated the Al content in the Al-substituted α-Ni(OH)2 was regulated by adjusting the molar ratio of pure α-Ni(OH)2 soaked in the solution and Al3+ dissolved in the solution. The Al element entered the lattice of pure α-Ni(OH)2 through a process of pure α-Ni(OH)2 dissolved followed by the precipitation of Al3+, Ni2+ and OH−. The S2O32− entered the interlayer of Al-substituted α-Ni(OH)2 through the formation process of the Al-substituted α-Ni(OH)2 or though ion exchange with the intercalated Cl−. The strongly alkaline solution soaking results demonstrated that Al-substituted α-Ni(OH)2 prepared by soaking pure α-Ni(OH)2 into AlCl3-containing solutions could preliminary get stabilized in the strongly alkaline solution.