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.