28 However, absence of a tunable band gap within the acceptable slot has limited their practical applications. 21 Several other 2D materials such as silicene, 22 germanene, 23 borophene, 24,25 stanene 26,27 and monochalcogenides 28 have been explored for their potential application as photocatalysts. 16,17 Although, its oxygenated counterpart is seen to have finite band gap of 2.4 eV to 4.3 eV, 18–20 it fails to be within the acceptable slot of 1.6–2.2 eV so as to be activated efficaciously under natural solar light irradiation. 14,15 However, due to its intrinsic zero band gap and consequently its instantaneous electron–hole recombination, its application in photocatalysis remains challenging. 14 Employment of graphene-based materials, to catalysis quickly has captured the interests of researchers in the last few decades. The journey of 2D materials based catalysts started with graphene, a single atom thick carbon sheet held by sp 2 hybrid bonds arranged in hexagonal manner. 11 (f) Lastly, quantum confinement and unsaturated surfaces leads to facile movement of electrons along in-plane direction, thus increasing the lifetime of charge carrier. 10 (e) They offer wide range of options for feasible chemical engagement, thereby enabling charge storage. 9 (d) 2D sheet being atomic thick, reduces charge carrier distance from the core to top, thereby reducing electron–hole recombination and enhancing the redox process marginally. 8 (c) Due to their promising thermal conductivity and large surface space, they also act as efficient heat sinks during exothermic reaction. 7 (b) Secondly, these materials offer higher thermal and mechanical stability and thus, operational ability at various temperatures. (a) Firstly, each site on their surface is equally accessible for catalytic process. 1–6 Among the various low dimensional nano-structures such as quantum dots/nanoparticles (zero dimensional), 1D nanotubes/nanorods and 2D nanofilms/nanosheets, 2D based materials have the upper hand with respect to other dimensional substances as catalysts due to the aforesaid reasons. However, the most widely applied area of these materials is catalysis on account of their higher surface to volume ratio and higher electron transferability making it cost effective. Various quantum phenomena such as phonon–electron interactions, spin interaction, quantum tunnelling effect and quantum confinement within these materials are responsible for their enhanced and yet tuneable electronic, thermal, magnetic and optical properties with far reaching applications in novel devices such as spintronics, photonics, quantum computing and catalytic materials. Low dimensional materials have been a buzzing topic of research in the last two decades due to their characteristic physico-chemical properties. Finally, this work opens up a driving lead of non-corrosive catalysts for water molecule splitting. The edge doped systems not only provide the chemical activity to activate water, but also show feasible HER overpotentials of 1.24–1.29 eV at neutral medium. Studies reveal that edge doping demonstrates better water molecule activation independent of S atom concentration. Photocatalytic activity is studied in terms of band gap and band alignment for different concentrations of the former. The cohesive energy studies predict the higher stability of even number S doped sheets as compared to their odd counterparts. central, edge and central edge positions with varying concentrations from 3.125% to 18.75% (corresponding to n = 1 to 6 sulphur atoms within a 32-atom blue-phosphorene sheet, P 32− nS n). The dopant is inserted at three locations viz. Metal-free element, sulphur, is explored as a dopant in a 32-atom blue-phosphorene sheet. a chemically tempered blue-phosphorene sheet, with single atom thickness and high carrier mobility. The present study illustrates the excellent photocatalytic potential of a two-dimensional material, viz. Several low dimensional materials have been explored for their photocatalytic properties on account of their surface to volume ratio. It is high time to placate the peak demand for an efficient, economic and green fuel in the form of H 2 through photocatalytic water splitting.
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