The thick consistency of synthesized zinc oxide nanoparticles (ZnO NPs) can be influenced by several factors. However, without specific details about the synthesis process and the intended application, it is difficult to determine whether a thick consistency is desirable or not. Here are a few possible reasons for the thick consistency and some considerations:

1. Concentration: The concentration of the ZnO NPs in the synthesis solution can affect the consistency. Higher concentrations often result in a thicker or more viscous solution. If a high concentration was intentionally used for the synthesis, the thick consistency might be desirable for certain applications.

2. Particle size and agglomeration: ZnO NPs tend to form aggregates or agglomerates due to their high surface energy. These agglomerates can contribute to a thicker consistency. Controlling the particle size and surface properties during synthesis can help minimize agglomeration and potentially lead to a smoother or less thick consistency.

3. Stabilizers or surfactants: The addition of stabilizers or surfactants during the synthesis process can influence the consistency of the ZnO NPs. These additives can affect the particle dispersion and prevent agglomeration, resulting in a more fluid or less thick consistency.

4. Solvent or medium: The choice of solvent or medium used for the synthesis can impact the consistency. Different solvents have different viscosities, and the choice of solvent can affect the dispersion and stability of the particles.