Photoluminescence properties of gallium-containing ZSM-5 zeolite were studied. It was found for the first time that reduced Ga-ZSM-5 containing low-valent Ga+ cations exhibits strong UV photoluminescence emission at 356 nm under excitation at 220 nm. This photoluminescence emission is induced by charge-transfer O-2 -Ga+ excitation transitions. (C) 2012 Elsevier B.V. All rights reserved.