Answer
$4H^{+} (aq) + TiO_{2}(s) + 2e^{-} → Ti^{2+} (aq) + 2H_{2}O$
This is a reduction reaction
Work Step by Step
We add water on the right hand side and H on the left hand side to balance the equation. Since Titanium is releasing two electrons and going from oxidation state of 0 to +2, this is a reduction reaction.