  In this work, we construct charged AdS black holes with a global monopole
charge in diverse dimensions and study the thermodynamics. We find a critical
monopole charge below which the solution exhibits Van-der Waals like behaviors.
In the context of holography, this could be intepreted using the boundary
degrees of freedoms. As an example, we study the phase diagram in the four
dimensions analytically. We further analyze the microstructures of the solution
using Ruppeiner geometry. We find that repulsive interactions dominates for
black holes in a wide range of temperatures. However, around the critical
point, attractive interactions is dominant and the Ruppeiner scalar curvature
shows universal behaviors: it has a critical exponent $2$ and coefficient
$-1/8$ in diverse dimensions. Universality of the results is interpreted from
the scaling behavior of free energy near the critical point for Van-der Waals
like fluids.
