Diborane reacts independently with ${\mathrm{O}}_2$and ${\mathrm{H}}_2\mathrm{O}$ to produce, respectively

Diborane reacts with water to form boric acid and hydrogen gas.

${\mathrm{B}}_2{\mathrm{H}}_6+3{\mathrm{H}}_2\mathrm{O}\to 2{\mathrm{H}}_3{\mathrm{BO}}_3+3{\mathrm{H}}_2$

Diborane reacts with oxygen to form boron trioxide and water.

${\mathrm{B}}_2{\mathrm{H}}_6+3{\mathrm{O}}_2\to {\mathrm{B}}_2{\mathrm{O}}_3+3{\mathrm{H}}_2\mathrm{O}$