Phosphorus modified and CuI incorporated polymeric g-C3N4 photocatalyst for efficient photocatalytic hydrogen production under direct solar light irradiation

• Published in: Materials science & engineering. B, Solid-state materials for advanced technology Solid-state materials for advanced technology, 2022-10, Vol.284, p.115873, Article 115873
• Main Authors: T.P., Rugma, Lakhera, Sandeep Kumar, Sahoo, Trilochan, Neppolian, Bernaudshaw
• Format: Article
• Language: English
• Subjects: Carbon nitride; Carrier recombination; Charge efficiency; CuI; Current carriers; Electromagnetic absorption; g-C3N4; Heterojunction; Heterojunctions; Hydrogen evolution; Hydrogen production; Light irradiation; Melamine; P-n junctions; Phosphorous; Photocatalysis; Photocatalyst; Photocatalysts; Photovoltaic cells; Red shift; Separation; Solar energy; Solar energy conversion
• ISSN: 0921-5107; 1873-4944
• DOI: 10.1016/j.mseb.2022.115873

[Display omitted] •g-C3N4/CuI (P-CN/CuI) photocatalysts was synthesized via facile wet-impregnation and pyrolysis routes.•P-CN/CuI exihibited high charge-carrier separation efficiency.•Na2H2PO4 treatment and CuI incorporation caused a red shift in the bandgap of g-C3N4.•P-CN/CuI photocatalyst produced ∼22 times higher hydrogen than bare g-C3N4. Polymeric carbon nitride (g-C3N4) is a promising 2D semiconducting photocatalyst for solar energy conversion applications. However, it suffers from poor performance due to sluggish charge carrier separation efficiency. Herein, we report a Na2H2PO4 treated g-C3N4/CuI (P-CN/CuI) photocatalysts with enhanced charge carrier separation at the interface of P-g-C3N4 and CuI. Double calcination of melamine at 650 °C caused a large redshift in the band tailing states and the energy bandgap, and treatment of g-C3N4 with Na2H2PO4 led to further improvement in the visible light absorption. The introduction of CuI into the P-CN matrix progressively improved the visible light absorption and charge carrier’s separation, as evident from the UV–vis and PL spectra. Due to the improved charge separation and light absorption properties, the P-CN/CuI photocatalyst produced ∼ 22 times higher hydrogen production than the bare g-C3N4. This work shows that non-metal doping and formation of a p-n heterojunction together could largely inhibit the charge carrier recombination in polymeric g-C3N4 for solar energy conversion applications.