Mohlaroyim Yuzuru G'ofurjonova You have precipitated Ni(OH)2 which can be thermally decomposed to NiO. Look at the phase diagram or a TGA plot to determine at which temperature this calcination should proceed.

To prevent the formation of precipitates during the synthesis of nickel oxide (NiO) by the sol-gel method, you can follow these guidelines:

Control pH: Maintain an appropriate pH level during the sol-gel process. The pH should be adjusted to a range that prevents the premature formation of hydroxides, which can lead to precipitates.

Slow Addition of Reactants: Add reactants slowly to ensure a uniform distribution and avoid localized supersaturation, which can cause precipitation.

Use of Stabilizing Agents: Incorporate stabilizing agents or surfactants that can help in preventing the aggregation of particles, thereby reducing the chance of precipitate formation.

Temperature Control: Maintain a consistent temperature during the sol-gel process. Abrupt temperature changes can cause nucleation and growth of unwanted precipitates.

Proper Solvent Choice: Use solvents that are compatible with the precursors and can effectively dissolve them without causing precipitation.

Aging Time: Allow sufficient aging time for the sol to convert to gel. Rushing this process can lead to incomplete reactions and precipitate formation.

Purity of Reagents: Use high-purity reagents to minimize the introduction of impurities that could initiate precipitation.

Mixing: Ensure thorough mixing of the sol to achieve a homogeneous solution, which helps in preventing localized concentrations that could lead to precipitation.

By carefully controlling these parameters, you can minimize the formation of precipitates and achieve a more uniform and high-quality nickel oxide product.