ES22-Karmakar

Author: Karmakar, Sreejani - Department of Physics, Indian Institute of Science Education and Research, Tirupati

Title: Hybrid DFT Based Prediction of a New Photocatalyst: g − B3C2N3

Abstract: Computational designing and screening of two dimensional materials to find efficient and stable photocatalyst is extremely important, in order to achieve green hydrogen fuel based economy. Here, using hybrid density functional theory (DFT) based calculation, a new two-dimensional (2D) B-C-N material, g−B3C2N3 is proposed to have promising prospect in metal-free photocatalysis. It is a direct band gap (3.69 eV), near UV absorbing semiconductor with robust dynamical and mechanical stability. The band positions with respect to water oxidation and hydrogen reduction potential levels, shows that g − B3C2N3 monolayer has the ability to be used for hydrogen fuel generation through spontaneous solar water splitting, over a broad pH range. To improve on the photon harvest efficiency and optimize the band alignment even further, the opto-electronic properties are modulated through biaxial strain application. Tensile strain application provides balanced HER-OER offsets with red shifted absorption spectra, implying higher photon harvest under solar irradiation. Moreover, the condition of pH and/or strain, g − B3C2N3 can be used as a key to control the redox offset and perform various photocatalytic reactions or suppress side reactions selectively, as per requirement. This may address many sustainable goals e.g. green energy production, carbon sequestration, waste water purification and beyond.

Other authors: Adhikary, Souren - Department of Physics, Indian Institute of Science Education and Research, Tirupati; Dutta, Sudipta - Department of Physics and Center for Atomic, Molecular and Optical Sciences - Technologies, Indian Institute of Science Education and Research, Tirupati