Encapsulating nano rods of copper–biphenylamines framework on g-C3N4 photocatalysts for visible-light-driven organic dyes degradation: promoting charge separation efficiency

Abstract

For the first time we have successfully constructed semi conductive copper–biphenylamines framework hybrid photocatalysts to degrade organic pollutants. Cu complexes sensitized photocatalysts of g-C₃N₄, i.e. CN-Cu(BN), CN-Cu(PD) and CN-Cu(BA), have been successfully tested for photocatalytic degradation of organic pollutants under visible light illumination, and a significant enhancement in catalytic activity was observed for CN-Cu(BA) in comparison to pristine g-C₃N₄. The modified material creates a charge separation with the electrons populating the higher CB and the holes the lower VB, thus enhancing the redox reaction power of the charge carriers. CN-Cu (BA) can easily degrade 99% of RhB in 1.5 hours and 60% of phenol in 2 hours. While the degradation efficiency of CN-Cu(BN), CN-Cu(PD) and g-C₃N₄ is lower than that of CN-Cu(BA). The k_obs for CN-Cu(BN) is 0.01985 min⁻¹, 5.2 times higher than that of g-C₃N₄, and that of CN-Cu(BA) is 0.0292 min⁻¹ which is 7.55 times greater than that of pristine g-C₃N₄. These degradation outcomes are favourable for developing a modified catalyst in bulk amount and its application. The strong holes can directly degrade RhB and phenol. Promoting the injection of electrons from g-C₃N₄ into the copper unit as well as strengthening the electronic interactions between the two units enhanced its activity.