Nanocrystalline, wurtzite structure ZnS and iron-doped ZnS were synthesized by a hydrothermal method. The visible light (lambda > 500 nm) driven photocatalytic activity of doped zinc sulfide was evaluated by the reduction of hexavalent chromium in water. ZnS-based materials exhibit high photocatalytic activity towards reduction of Cr(VI) due to its low potential of conduction band edge. Moreover, the reaction yield increased in the presence of organic contaminants. In parallel, ability of ZnS towards degradation of organic pollutants such as detergents has been also demonstrated. Thermodynamic and kinetic aspects of processes have been studied. Photocatalysts based on zinc sulfide seem to be particularly attractive for wastewater treatment: the efficiency of photocatalytic process increase in the presence of organic contaminants and highly toxic hexavalent chromium is reduced to Cr(0), that is very easy to remove by sedimentation. Moreover, materials are active under natural sunlight. (C) 2018 Elsevier B.V. All rights reserved.