The photocatalytic HCrO4- reduction was investigated in air equilibrated solution using the spinel CuFe2O4 nanoparticles as sensitizers. The oxide is p-type semi conductor, prepared from nitrates decomposition. The catalytic performance increases with decreasing pH and the concomitant oxidation of salicylic acid contributes significantly to the photoactivity through the charges separation of electron/hole pairs (C7H6O3 + 6 O-2 + 4h(+) + 3 H2O --> 7 CO2 + 4 H3O+). Evidence has been given to show the advantages of the hetero-system CuFe2O4/CdS in the chromate reduction. CuFe2O4 acts as electrons pump and the electron transfer to chromate is mediated via CdS hexagonal variety (greenockite). A reduction of 60% occurs and the process is well described by a pseudo first order kinetic with a half life of similar to 2.8 h and a quantum yield of similar to 0.12% for an initial HCrO4- concentration of 3 x 10(-4) M. An improvement up to 72% is obtained when the reaction occurs in a stirred reactor and no cadmium was detected after 6h illumination. The results indicate a competitive effect with the water reduction. The hydrogen evolutions are found to be 0.236 and 0.960 cm(3) mn(-1) g(-1) in presence and in absence of HCrO4-, respectively. (C) 2010 Elsevier B.V. All rights reserved.