AUTHOR=Das Sabuj Kanti , Shyamal Sanjib , Das Manisha , Mondal Saptarsi , Chowdhury Avik , Chakraborty Debabrata , Dey Ramendra Sundar , Bhaumik Asim TITLE=Metal-Free Pyrene-Based Conjugated Microporous Polymer Catalyst Bearing N- and S-Sites for Photoelectrochemical Oxygen Evolution Reaction JOURNAL=Frontiers in Chemistry VOLUME=Volume 9 - 2021 YEAR=2021 URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2021.803860 DOI=10.3389/fchem.2021.803860 ISSN=2296-2646 ABSTRACT=The development of an efficient, sustainable and inexpensive metal-free catalyst for oxygen evolution reaction (OER) via photoelectrochemical water splitting is very demanding for the energy conversion devices like green fuel generators, fuel cells and metal-air batteries. Herein, we have developed a metal-free pyrene-based nitrogen and sulphur containing conjugated microporous polymer having high BET surface area (761 m2 g-1) and low band gap of 2.09 eV for OER from alkaline solution. The π-conjugated as synthesized porous organic material (PBTDZ) has been characterized by Fourier transform infrared spectroscopy (FT-IR), solid state 13C (cross-polarization magic angle spinning-nuclear magnetic resonance) CP-MAS NMR, N2 adsorption/desorption analysis, field-emission scanning electron microscope (FESEM), high resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA) experiments. The material acts as an efficient catalyst for photoelectrochemical OER with a current density of 80 mA/cm2 at 0.8 V vs Ag/AgCl and delivered 104 mmol of oxygen in 2 h run. The presence of low band gap energy, π-conjugated conducting polymeric skeleton bearing donor heteroatoms (N and S), and higher specific surface area associated with inherent microporosity are responsible for this admirable photoelectrocatalytic activity of PBTDZ catalyst.