Melem Hydrate-Derived g-C3N4 Micro-Rods Coordinated with Cu2+: Why is Cu a superior cocatalyst compared to Ni and co?

• Main Authors: Pandi K., Kangeyan K.P., Lakhera S.K., Kiong T.S., Bernaurdshaw N.
• Other Authors: 57218799806
• Format: Article
• Published: Elsevier Ltd 2025
• Subjects: Carbon nitride; Charge transfer; Hydrates; Hydration; Hydrogen production; Nickel; Photoluminescence spectroscopy; Co catalysts; G-C3N4; Graphitic carbon nitrides; H 2 production; High charges; Melem hydrate; Metal nitrate hydroxide; Microrods; Performance; Visible-light activity; Cost effectiveness

Graphitic carbon nitride (g-C?N?) holds significant promise for hydrogen production due to its visible-light activity, stability, and cost-effectiveness. However, it faces challenges related to high charge recombination and trapping, which ultimately hinders its photocatalytic efficiency. In this study, we address these limitations by first modifying g-C?N? nanosheets into rods through the formation of melem hydrate using an ultrasonication method. Subsequently, the melem hydrate is transformed into g-C?N? micro-rods (CNR). These CNR micro-rods are further coordinated with transition metals (Ni2?, Co2?, and Cu2?) via a hydrothermal process. Among these samples, the Cu-coordinated micro-rods exhibit the highest photocatalytic hydrogen production rate, achieving 4 mmol/g/h. This performance surpasses previously reported novel metal-coated g-C?N? materials. Notably, when compared to Ni and Co, the Cu-coordinated g-C?N? produces 2.8- and 3.6-times higher hydrogen, respectively. The enhanced performance is attributed to faster interfacial charge transfer kinetics between g-C?N? micro-rods and Cu, as evidenced by the highest kNT value of 0.81 ns?1 and kET value of 0.16 ns?1, measured using time-resolved photoluminescence spectroscopy. ? 2024 Elsevier Ltd