Panchromatic Pt/TiO2-Based Photocatalysts Sensitized with Carboxylated Chlorin Dyads for Water Splitting Hydrogen Evolution

•Three chlorophyll (Chl)-related dyad sensitizers were designed and synthesized by covalently-linking two different types of chromophore units derived from natural abundant Chls-a/b and realize panchromatic light absorption for Pt/TiO2 photocatalytic system.•Intramolecular fluorescence resonance energy transfer (FRET) occurs in Chl-PPb and thus influences the H2 evolution efficiency.•The highest H2 evolution efficiency reached 5.4 mmol g-1h−1 with the turn-over numbers (TONs) of 812.•The competition of absorption by PPd moiety and the Chl unit of Chl-PPd in the short wavelength region decreased the H2 evolution efficiency.