Chapter 10 Bismuth-Based Compounds as Visible Light Photocatalyst for Remediation and Water Splitting Mahboobeh Zargazi and Mohammad Chahkandi Contents 10.1 Introduction .............................................................................. 322 10.2 Photocatalyst Semiconductors ........................................................... 323 10.2.1 Bicompounds ................................................................. 324 10.2.2 Modification of Bicompounds ............................................... 334 10.3 Application ............................................................................... 343 10.3.1 Water Remediation ............................................................. 343 10.3.2 Water Splitting .................................................................. 345 10.4 Conclusions and Prospects ............................................................... 347 References ....................................................................................... 349 Abstract Enhancing demand for environmental protection has become an urgent need more than ever. For this purpose, water the most known indispensable essences for survivorship of aboveground organisms should be specifically considered. Today, quality of water as dominant source influence of the animate systems has been endangered by various harmful contamination levels. Accordingly, rescuing approaches and cleaning compounds in safe manner demanding for improvement of the quality of potable and industrial utilizing waters are daily pursued. Different materials of bismuth having layered structures, hybridized orbitals, low band gap, and band positions can be attended because of significant ability of water remedia- tion. At this book chapter, we reviewed the photocatalytic efficiency of Bicompounds, the heterojunction and Zscheme composites of them, and the synthetization method. Heterojunction or Zscheme combinations led to obtain high separation photogenerated electronshole and reduction of the recombination rate. Furthermore, type II of heterojunction and Zscheme connections with other M. Zargazi (*) Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran M. Chahkandi (*) Department of Chemistry, Hakim Sabzevari University, Sabzevar, Iran e-mail: m.chahkandi@hsu.ac.ir © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 Inamuddin et al. (eds.), Water Pollution and Remediation: Photocatalysis, Environmental Chemistry for a Sustainable World 57, https://doi.org/10.1007/978-3-030-54723-3_10 321