Carbon Nitride Photocatalysts for Improved H2 Production in Different Water Matrices

Abstract

Graphitic carbon nitride (g-C₃N₄) based-photocatalysts were prepared from melamine, exfoliating the carbon nitride with a double microwave-assisted thermal treatment. The presence of a small amount of Pt (0.75 wt%) as cocatalyst led to an efficient H₂ production through visible-light glucose photoreforming, also changing the water matrices from ultrapure water to wastewater or seawater. Interestingly, the examined photocatalyst showed higher H₂ evolution in wastewater and in seawater than in ultrapure water in overall water splitting tests (i.e., without the addition of glucose). The photocatalyst demonstrated high stability and reusability in the different water matrices. To increase its applicability, the photocatalyst was also immobilized in film form, while maintaining remarkable photocatalytic activity and showing a higher apparent quantum yield at 420 nm (9.5%) compared to the sample in the powder form (3%). The ease of synthesis and effective performance make this approach promising for the development of a new class of visible-light-driven photocatalysts for sustainable H₂ production.