Branched TiO2/Si nanostructures for enhanced photoelectrochemical water splitting

► Successful demonstration of nanoscale heterogeneous integration of TiO2 and Si. ► Fabrication specifics of three-dimensionally branched TiO2/Si nanowire array described. ► Application of the 3D branched TiO2/Si nanowire array photoelectrode for PEC water splitting. ► Demonstration of enhanced light absorption and energy conversion by the 3D nanostructure.