Charge transfer and recombination at the single crystalline ZnO photoanode were studied by a combination of dc and ac techniques. The potential dependence of the spectrally resolved photoluminescence gives information on the competition between bulk recombination and electron−hole pair separation. The kinetics of surface recombination were studied by electrical and optoelectrical admittance spectroscopy. These results provide insight into the mechanisms of recombination and charge transfer at ZnO photoanodes.