Abstract The photoelectrochemical properties and the diffuse reflection spectra of the titanates K 1.8 M 2+ 0.9 Ti 7.1 O 16 (M 2+ = Mg 2+ , Ni 2+ ) and K 1.8 M 3+ 1.8 Ti 6.2 O 16 (M 3+ = Al 3+ , Cr 3+ ) with the hollandite structure are reported. The white titanates K 1.8 Mg 0.9 Ti 7.1 O 16 and K 1.8 Al 1.8 Ti 6.2 O 16 show an optical absorption edge near 3.7 eV. These compositions can be coloured by transition-metal ions due to the occurrence of Me n+ → Ti 4+ charge-transfer transitions. When these coloured titanates were used as photo-anodes in a photoelectrochemical cell for water electrolysis, no photoresponse was observed with visible light irradiation. Possible reasons are discussed.