Recent advances in anion doped g-C3N4 photocatalysts: A review

Today's rapid industrialization and globalization have provoked the sustainable chain of diversity. Photocatalytic nano-materials are emerging to combat two major problems like environmental pollution and energy crisis. In this regard, incredible experimental as well as theoretical studies have been done to realize the characteristic properties of g-C3N4, as a metal free polymeric photocatalytic nano-material. However, because of some important limitations, like low-surface area, limited light absorption, quantum confinement effect and low-dimensionality, diversified modification like band structure engineering, doping, defecting and designing of heterojunction/composites etc. were introduced to broaden its prospective applications. Amongst, band gap engineering through elemental doping is considered as a successful approach to modify its optical as well as electronic properties. In this review, we have highlighted synthesis methods, distinct doping mode of the dopants, complexity due to the dopants, benefits of co-doping, mechanism involved in the photo catalytic performance of various anion doped g-C3N4 based photo catalyst. Incorporation of non-metallic elements plays an unique role in enhancing light absorption and tuning the band potentials to bring about targeted redox reactions. It can pave a novel avenue for the advances of element doped g-C3N4 systems towards visible-light driven photo catalysis. Although we have critically discussed the mono/bi/tri-anion doped g-C3N4 systems, our aim is to showcase the broader version to develop these systems in a sustainable manner. (C) 2020 Elsevier Ltd. All rights reserved.