Alhamdulillah, ada jawabannya di [1] :
\documentclass{article}
\usepackage{multicol,lipsum,xparse}
\let\multicolmulticols\multicols
\let\endmulticolmulticols\endmulticols
\RenewDocumentEnvironment{multicols}{mO{}}
{%
\ifnum#1=1
#2%
\else % More than 1 column
\multicolmulticols{#1}[#2]
\fi
}
{%
\ifnum#1=1
\else % More than 1 column
\endmulticolmulticols
\fi
}
\begin{document}
\begin{multicols}{2}[\section{Title in single column}]
\lipsum[1-2]
\end{multicols}
\begin{multicols}{1}
\lipsum[1-2]
\end{multicols}
\end{document}
Referensi
- one-column multicol environment, http://tex.stackexchange.com/questions/233866/one-column-multicol-environment