  The Zero divisor Graph of a commutative ring $R$, denoted by $\Gamma[R]$, is
a graph whose vertices are non-zero zero divisors of $R$ and two vertices are
adjacent if their product is zero. In this paper, we consider the zero divisor
graph $\Gamma[\mathbb{Z}_n]$ for $n=p^3$ and $n=p^2q$ with $p$ and $q$ primes.
We discuss the adjacency matrix and eigenvalues of the zero divisor graph
$\Gamma[\mathbb{Z}_n]$. We also calculate the energy of the graph
$\Gamma[\mathbb{Z}_n]$.
