Efficient Photocatalysis of Composite Films Based on Plasmon-Enhanced Triplet-Triplet Annihilation

To avoid secondary environmental pollution caused by photocatalysts in their applications, our work offers a new strategy for fabricating photocatalytic films based on plasmon-enhanced triplet-triplet annihilation upconversion (TTA-UC). Polydimethylsiloxane (PDMS) films containing platinum (II)-octaethylporphyrin and 9,10-diphenylanthracene (PtDPAP), and gold nanoparticles (AuNPs) were prepared. While graphene (G) was used as an adhesive and conductive layer, CdS nanoparticles were deposited onto the films (AuNPs-PtDPAP/G/CdS) by plasma glow discharge pretreatment. The AuNPs-PtDPAP film had an enhancement in the green-to-blue upconversion compared with the pristine PtDPAP film. CdS can utilize the AuNPs plasmon-enhanced TTA-UC photons to realize efficient photocatalytic reactions. The pseudo-first-order rate constant (k_pfo) of the optimized active and stable photocatalytic film, 0.3 AuNPs-PtDPAP/G/CdS, reached 0.294 h^-1 for tetracycline degradation under green light irradiation. Its k_pfo in decomposing tetracycline under visible light is 2.62 times higher than that of the PtDPAP/G/CdS. The reported composite films provide a strategy to improve the photocatalytic activity and promote the practical applications of nanosize photocatalysts.