Bold upright i-hat and j-hat for vector notation

For bold and upright, you could use the regular text-version of \imath and \jmath, which are \i and \j:

\newcommand{\ihat}{\hat{\textbf{\i}}}
\newcommand{\jhat}{\hat{\textbf{\j}}}

Additionally, if you want the \hat to be bold as well, then use \boldsymbol.

\newcommand{\ihat}{\boldsymbol{\hat{\textbf{\i}}}}
\newcommand{\jhat}{\boldsymbol{\hat{\textbf{\j}}}}

\DeclareMathSymbol{\ii}{\mathalpha}{letters}{"10}
\DeclareMathSymbol{\jj}{\mathalpha}{letters}{"11}

\newcommand{\ihat}{\mathbf {\hat{\ii}}}
\newcommand{\jhat}{\mathbf {\hat{\jj}}}
\newcommand{\vect}{\mathbf}

The last line is a better definition of your \vect command.

\newcommand{\ihat}{\textbf{\^\i}}
\newcommand{\jhat}{\textbf{\^\j}}

This is a simplification of Werner's answer.