Sn-doped g-C3N4 as a novel photoelectrocatalyst for water oxidation

• Published in: The Journal of physics and chemistry of solids 2023-05, Vol.176, p.111242, Article 111242
• Main Authors: Aboubakr, Ahmed Esmail A., Khan, Malik Dilshad, Revaprasadu, Neerish, Millet, Pierre, Hung, Chen-Hsiung, El Rouby, Waleed M.A.
• Format: Article
• Language: English
• Subjects: Photoanode; Photoelectrochemical impedance spectroscopy; Sn-doped g-C3N4; Water splitting
• ISSN: 0022-3697; 1879-2553
• DOI: 10.1016/j.jpcs.2023.111242

The photocatalytic performance of graphitic carbon nitride can be enhanced multifold by introducing suitable dopants. Here we report incorporating a cost-effective, non-toxic and abundant element, i.e., tin, in elongated semiconducting carbon nitride (g-C3N4). A novel procedure was used to introduce varying amounts of tin to the g-C3N4 framework. The new photocatalysts (Sn–CN) were characterized by X-Ray Diffraction (XRD) and FT-IR measurements, confirming the absence of tin oxide and incorporation of tin in the g-C3N4 backbone. The SEM, EDX, TEM and XPS measurements demonstrated the elongated morphology and the presence of tin in the composite materials. BET measurements showed a relative increase in the specific surface area for the composites. The optical measurements showed enhanced solar light absorption and promoted the charge carrier's separation after the insertion of Sn to g-C3N4. Photoelectrochemical water dissociation measurements showed that 10% tin doping increased the activity of g-C3N4 to water photo-oxidation about four times. This improvement was analyzed by electrochemical impedance spectroscopy measurements. •g-C3N4 materials was synthesized from melamine.•The as-prepared material was doped with tin to adjust the band gap.•10% Sn doping showed a 12-fold electron-hole separation, compared to pristine g-C3N4.•PEC water splitting activity was enhanced by 4 times after doping g-C3N4 with 10% Sn.•Mott–Schottky plots were used to determine the conduction and valence bands' values.