Insights into Atomic Level π‐Electron Modulations in Supramolecular Carbon Nitride Nanoarchitectonics for Sustainable Green Hydrogen Production

Abstract

AbstractCarbon nitrides, metal‐free semiconducting materials, have unique molecular structure and semiconducting properties which have inspired researchers to utilize them as photocatalysts for the sustainable production of hydrogen. However, they suffer from a few drawbacks including fast charge‐carrier recombination rate and low charge transfer efficiency owing to their amorphous and less conducting wall structure which remain as significant challenge for achieving breakthrough in photocatalytic water splitting. Herein, the study reports a supramolecular approach of coupling thiourea and trimesic acid for designing highly efficient C‐doped carbon nitride photocatalysts in which the π‐electron density is precisely manipulated. The developed C‐doped carbon nitride demonstrates the fine‐tuned band positions, the mitigated electron–hole recombination, and enhanced conductivity, resulting in the facilitation of significantly enhanced hydrogen generation through the photocatalytic water splitting under the solar‐simulated light. The position and distribution of C‐doping in the carbon nitride framework are characterized by using advanced analytical techniques such as X‐ray photoelectron spectroscopy, near‐edge X‐ray absorption fine structure spectroscopy, and electron paramagnetic resonance spectroscopy together with the first‐principles studies of the electronic structure and energetics of doping. The remarkable increase in photocatalytic hydrogen generation by using developed C‐doped carbon nitride brings one step closer to achieving a green hydrogen economy.