A direct polymeric carbon nitride/tungsten oxide Z‐scheme heterostructure for efficient photocatalytic hydrogen generation via reforming of plastics into value‐added chemicals
Ruizhe Wang, Zhi Lin, Yiqing Wang, Kaini Zhang, Gehong Zhang, Jie Zhang, Samuel S. Mao, Shaohua Shen
Abstract
Abstract To promote charge transfer and separation for efficient photocatalysis, a direct Z‐scheme heterostructure was constructed by coupling polymeric carbon nitride (PCN) and WO 3 . Interestingly, the obtained PCN/WO 3 Z‐scheme heterostructure could photocatalytically produce hydrogen and value‐added chemicals (e.g., formate and acetate) by reforming of plastic polylactic acid (PLA) in alkaline aqueous condition. By optimizing WO 3 contents and reaction conditions, the obtained PCN/WO 3 heterostructure exhibits much increased photocatalytic activity for PLA photoreforming under visible light, with hydrogen evolution rate reaching 402.90 μmol·g −1 ·h −1 , which is 3.5 times that of PCN. It is revealed that the Z‐scheme charge transfer between PCN and WO 3 mainly contributes to the promoted charge separation and thus the improved photocatalytic activity. Moreover, with h + and ·OH experimentally evidenced as the predominant active species, a possible reaction pathway for the reforming of PLA into value‐added chemicals (e.g., formate and acetate) over PCN/WO 3 Z‐scheme heterostructure is cleared by monitoring the reaction intermediates and radicals. This work paves a carbon neutrality and scalable route toward the synergistical production of hydrogen and value‐added chemicals by utilizing and recycling plastic waste.