This review article comprehensively discusses the recent development of band engineering ways, synthetic methods, and photocatalytic applications using ZnS nanocrystalline semiconductors. The band engineering is just the first step in the design of visible-light-driven photocatalysts. Particle size, shape, surface area, crystal structure, and degree of crystallinity also affect photocatalytic activity. The reason we chose ZnS as a target is due to its remarkable chemical stability against oxidation and hydrolysis when the particle size steps down to just a few nanometers. In addition, photocatalytic water splitting technology driven by ZnS photocatalyst has great potential for low-cost and environmentally friendly solar-hydrogen production to support the future hydrogen economy. Therefore, the ZnS assisted photocatalytic degradation of pollutants and water splitting under various conditions have been summarized in this review article. The possible reaction mechanisms for organic pollutants degradation and the photocatalytic hydrogen evolution using the metal-doped ZnS photocatalysts have been also included and compared. (C) 2017 Elsevier B.V. All rights reserved.