Universal integration of photothermal particles onto g-C3N4 towards improved photocatalysis

Abstract

The photothermal effect has been recognized as a universal promoter in various photocatalytic reactions. However, in many promising nanocomposite systems, the integration of heterogeneous photothermal materials with photocatalysts remains a significant technical challenge. Focusing on the emerging graphitic carbon nitride (g-C₃N₄) based photocatalyst, we identified that the segregation of the introduced photothermal particles results from the dynamic instability of the original solid-solid dispersion system, which essentially origins from a sluggish two-step solid-liquid-solid phase transformation of urea towards g-C₃N₄. By taking advantages of the photothermal particles to be loaded, we developed a photothermal-polymerization strategy to create a rapid heating to overcome their undesired segregation during g-C₃N₄ formation. The strategy enables a one-step loading of various photothermal particles on the g-C₃N₄, presenting a versatile methodology. This sustainable technique enhances the synthesis yield of g-C₃N₄ by 352 % with reduced energy consumption. The derived photothermal particles-dispersed g-C₃N₄ shows 290 % improvement in photocatalytic CO₂ reduction compared to the separated system, which is obtained from the traditional heating synthesis. Beyond enriching the accessible categories of composite catalysts, this study may deepen physiochemical insights into the dynamic transformation of the novel dispersion system.