Place boundary of two adjacent nodes on top of each other

Question

If I place two nodes adjacent to each other the resulting boundary between the nodes is doubled making it more thick than other boundarys. Is it possible to place them on top of each other in order to keep the original thickness?

Here my code and below some example pictures:

\documentclass[10pt,a4paper]{article}
\usepackage[utf8]{inputenc}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{tikz}
\usetikzlibrary{positioning}

\begin{document}

\begin{figure}
\begin{center}
\begin{tikzpicture}

\tikzstyle{node} = [draw, rectangle, minimum width=1cm]
\node [node] (n_one) {node 1};
\node [node, right = 0cm of n_one.north east, anchor = north west] (n_two) {node 2};

\end{tikzpicture}
\end{center}
\end{figure}

\end{document}

Answer 1

You can shift the right node by one line width:

\documentclass[10pt,a4paper]{article}
\usepackage[utf8]{inputenc}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{tikz}
\usetikzlibrary{positioning}

\begin{document}

\begin{figure}
\begin{center}
\begin{tikzpicture}

\tikzstyle{node} = [draw, rectangle, minimum width=1cm]
\node [blue,node] (n_one) {node 1};
\node [red,node, right = -\the\pgflinewidth of n_one.north east, anchor = north west] (n_two) {node 2};

\end{tikzpicture}
\end{center}
\end{figure}

\end{document}

Or you could draw only a single node:

\documentclass[10pt,a4paper]{article}
\usepackage[utf8]{inputenc}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{tikz}
\usetikzlibrary{positioning}
\usetikzlibrary{shapes.multipart} 

\begin{document}

\begin{figure}
\begin{center}
\begin{tikzpicture}
\node[
  rectangle split, 
  rectangle split parts=2,
  draw, 
  rectangle split horizontal,
  rectangle split part align={center, top, bottom}
] at (0,0)  {node 1\nodepart{two}node 2};
\end{tikzpicture}
\end{center}
\end{figure}

\end{document}