Enhanced photocatalytic hydrogen evolution over a heterojunction composed of silver cyanamide and graphitic carbon nitride

Abstract

As photocatalysts, heterojunction materials have attracted much attention because of their capacity to integrate the promising performance of the individual components. Here, a series of heterojunction materials composed of silver cyanamide (Ag₂NCN) and graphitic carbon nitride (g-C₃N₄) have been fabricated using a facile grinding method. Upon photoexcitation, the heterojunction materials exhibited enhanced photocatalytic activity in the hydrogen evolution reaction (322.35 μmol g⁻¹ h⁻¹), 82.87 and 117.65 times higher than that of the pristine Ag₂NCN and g-C₃N₄, respectively. The photoelectrochemistry results revealed that the loading of Ag₂NCN onto g-C₃N₄ could be favorable to the photogenerated charge separation and transfer in the heterojuction system. In addition, the spent heterojuction retained a better photocatalytic activity after 30 hours recycling. Furthermore, the excellent synergetic effect between Ag₂NCN and g-C₃N₄ could achieve the effectively promoted separation of photogenerated electron–hole pairs, thus leading to the enhancement of photocatalytic performance under simulated sunlight illumination. This work could provide a general strategy to fabricate Ag-based materials on g-C₃N₄ photocatalysts with superior H₂ evolution performance.