CdS/Pt photocatalytic activity boosted by high-energetic photons based on efficient triplet–triplet annihilation upconversion

We herein report the triplet–triplet annihilation upconversion luminescence (TTA-UCL) clusters achieved by loading the platinum(II)-octaethylporphyrin (PtOEP) and 9,10-diphenylanthracene (DPA) into silica shells. This aqueous-based system possesses a core–shell structure which is of crucial importance for enhancing the mobility of core liquid. The encapsulated clusters with efficient green-to-blue upconversion without deoxygenation are conjoined with cadmium sulfide (CdS) as the photocatalyst. Platinum (Pt) is used to improve the separation of electron−hole pairs on the photocatalytic system. Given the band gap of photocatalysts, tetracycline (TC) degradation and photoinduced hydrogen evolution are used to perform the photocatalytic activity. CdS loaded with Pt has higher Pseudo-first-order rate constant (k_pfo) in decomposing tetracycline than pure CdS. Moreover, the excellent hydrogen evolution property appears when the converted high energy photons from TTA-UCL-based clusters are introduced to the photocatalytic system. The quantum efficiency of hydrogen evolution increases further after the cocatalyst Pt deposition. This work not only fabricates an encapsulated structure for TTA-UCL clusters, but also provides an effective TTA-supported upconversion-photocatalysis system.