Phosphorous, boron and sulfur doped g-C3N4 nanosheet: Synthesis, characterization, and comparative study towards photocatalytic hydrogen generation

Phosphorus, sulfur, and boron doped graphitic carbon nitride were successfully synthesized by solidstate calcination of melamine, as precursor of g-C3N4 and ammonium dihydrogen phosphate [NH4(H2PO4)], thiourea (CH4N2S), and boric acid (H3BO3) as dopant. The as synthesized materials were further subjected to chemical exfoliation using hydrochloric acid as exfoliating agent. The different physicochemical properties of the synthesized materials were well characterized by means of Powder X-ray diffraction (PXRD), UV-Visible diffuse reflectance absorption spectra (UV-DRS), photoluminescence spectra (PL), and electrochemical measurement. Boron doping into the bulk CN lattice enhance the absorption of light, electron-hole separation as revealed from absorption and PL emission spectra. From the photocurrent and impedance spectra it is clear that boron doping not only enhances the photocurrent value but also decreases the charge transfer resistance of the parent material. All synthesised materials were tested for photocatalytic hydrogen evolution reaction, out of which CNB shows highest rate of hydrogen generation (18.2 mu molh(-1)) which is around three times more than that of g-C3N4. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

The study successfully synthesized phosphorus, sulfur, and boron doped graphitic carbon nitride, with boron doping showing enhanced light absorption and electron-hole separation, leading to significantly improved photocurrent value and reduced charge transfer resistance.