Visible-light-driven hydrogen production is a promising pathway to realize efficient solar energy utilization. Here, Nd3+ incorporated ZnIn2S4 (Nd-ZIS) was synthesized via facile one step hydrothermal method. Raman spectroscopy and X-ray Photoelectron Spectroscopy (XPS) confirm the successful incorporation of Nd3+ in ZnIn2S4. Optical studies reveal the reduction of effective bandgap from 2.7 eV to 2.54 eV upon incorporation of Nd3+ with improved charge carrier life time of 3.12 ns. Electronic properties of ZIS and Nd-ZIS were investigated from first principle calculations. An attempt to improve photocatalytic activity of ZIS by modification with Nd3+ ions resulted in degradation of organic pollutant up to 98% under natural sunlight and decrease in life time of trap states up to a nominal value of 200 ms (as evident from photoelectrochemical measurements). The mechanism behind enhancement of photocatalytic activity of ZIS post Nd3+ integration has been proposed. Nd-ZIS was also utilized for water splitting activity exhibiting a considerable H-2 generation similar to 3415 mu mol g(-1). To the best of our knowledge, activity of Nd3+ incorporated ZIS has been explored for the first time in present work. It is believed that an in-depth understanding of photoactivity of ZIS would be significantly important for designing materials with desired photocatalytic performance in future. (C) 2020 Elsevier Ltd. All rights reserved.