摘要：Noble metal cocatalysts have shown great potential in boosting the performance of CdS in photocatalytic water ***,the mechanism and kinetics of electron transfer in noble-metal-decorated CdS during practical hydrogen evolution is not clearly ***,Pt-nanoparticle-decorated CdS nanorods(CdS/Pt)are utilized as the model system to analyze the electron transfer kinetics in CdS/Pt *** femtosecond transient absorption spectroscopy,three dominating exciton quenching pathways are observed and assigned to the trapping of photogenerated electrons at shallow states,recombination of free electrons and trapped holes,and radiative recombination of locally photogenerated electron-hole *** introduction of Pt cocatalyst can release the electrons trapped at the shallow states and construct an ultrafast electron transfer tunnel at the CdS/Pt *** CdS/Pt is dispersed in acetonitrile,the lifetime and rate for interfacial electron transfer are respectively calculated to be~5.5 ps and~3.5×10^(10) s^(−1).The CdS/Pt is again dispersed in water to simulate photocatalytic water *** lifetime of the interfacial electron transfer decreases to~5.1 ps and the electron transfer rate increases to~4.9×10^(10) s^(−1),confirming that Pt nanoparticles serve as the main active sites of hydrogen *** work reveals the role of Pt cocatalysts in enhancing the photocatalytic performance of CdS from the perspective of electron transfer kinetics.

摘要：Intrinsic broadband photoluminescence(PL)of self-trapped excitons(STEs)are systematically studied in lead-free double perovskite nanocrystals(NCs).It is clarified that bandgap(direct/indirect)has important influence on the PL properties of STEs:indirect bandgap NCs exhibit strong exciton-phonon coupling which results in non-radiative STEs,while direct bandgap NCs exhibit moderate exciton-phonon coupling,inducing bright STE ***,by alloying K+and Li+ions in Cs2AgInCl6 NCs,the NCs exhibit broadband white-light ***-carrier dynamics study indicates that the efficient white-light emission originates from the further suppressed non-radiative processes of the STEs in the direct bandgap *** work may deepen the understanding of STEs and guide the design of highperformance lead-free perovskites.