Abstract Co‐catalysts are commonly employed as catalytic centers to activate reactants and intermediates for driving redox reactions with photogenerated carriers during photocatalysis. Herein, a group of electronically inverted perovskite‐type nitrides Cu x In 1− x NNi 3 (0 ≤ x ≤ 1) are reported as novel and versatile co‐catalysts for the significantly enhanced photocatalytic hydrogen production performance on various photocatalysts, such as metal sulfides (CdS, ZnIn 2 S 4 ), carbon nitride (g‐C 3 N 4 ), and metal oxide (TiO 2 ), respectively. The hybrid photocatalyst Cu 0.5 In 0.5 NNi 3 /CdS exhibits an optimal activity up to 6945 µmol g −1 h −1 and a remarkable enhancement factor of 6146% compared with that of pristine CdS. Besides, a high reaction stability with repetitive photocatalytic cycles is achieved. The obvious improvement of activity can be ascribed to the promoted charge separation of energetic carriers due to the metallic properties of Cu x In 1− x NNi 3 and abundant Ni active sites. A near‐zero Gibbs free energy of adsorbed atomic hydrogen on the Ni‐site is thermodynamically favorable for hydrogen evolution, which can be regulated by electronic states of A‐sites (Cu/In). This work not only demonstrates the great potential of perovskite‐structured nitrides as a universal platform for enhanced photocatalysis but also addresses the importance of exploring new catalytic applications for unique perovskite‐derivatives with cations/anions exchanged in coordinated sites of polyhedral.
Abstract Broadband emissive perovskites are next‐generation materials for solid‐state lighting and radiative detection. However, white‐emitting perovskites are generally synthesized by regulating B/X sites, while not enough attention is paid to the A‐site, which is thought to hardly affect the band‐edge structures and optoelectronic properties. Here, a series of Sb 3+ ‐doped In‐based 0D halide perovskite derivatives are described with various organoammonium cations in A‐sites. Warm‐white light emitting across the visible spectrum (450–850 nm), large Stokes shifts, and high photoluminescence quantum yields are easily tunable by molecularly tailoring A‐site cations. These features enable a light yield up to 60976 Photons/MeV as X‐ray scintillator, and a detection limit of 90 nGy air /s that is ≈60 times lower than the medical requirement. It is proved that A‐site plays a critical role in determining the degree of distortion of polyhedra, which influences the broadband photoluminescence and self‐trapped exciton (STE) dominates the emission process. Moreover, for the first time, via the incorporation of 2,6‐dimethylpiperazine, a mixed A‐site regulating strategy produces a standard white‐light emission, which originates from the blue‐light and yellow‐light related to various STE emission centers. It is foreseen that this strategy highlights the expanded role of A‐site and the importance of rethinking A‐sites in perovskites.
Light-to-heat conversion represents one of the most promising pathways to utilize full-spectrum solar energy. The key for boosting the photothermal conversion in semiconductor-based light absorbers relies on narrowing the bandgap for harvesting wide-range sunlight and localizing thermal energy via decreasing heat loss. Here, we demonstrate the first example of using a halide perovskite, Cs4CuSb2Cl12, as the photothermal material for efficient solar-to-heat conversion, with an intrinsic narrow bandgap and ultralow thermal conductivity. Full-spectrum (200–2500 nm) absorption and solar-thermal conversion efficiency up to 93.4% are achieved. The photothermal property enables a low-temperature and rapid hydrogen production from ammonia borane, with 2.0 equiv of hydrogen released, and a photothermal activation efficiency of 12.2% is realized, without any extra energy input. This high photothermal performance not only provides a potential for an energy-efficient on-board hydrogen supply for fuel cells but also opens up a new field for halide perovskites utilized as photothermal convertors.
The creation of junctions between 0D and 2D materials can be an efficient strategy to enhance charge separation for solar hydrogen production. In this study, a simple in situ growth method has been used to synthesize a series of 0D/2D Zn-Ag-In-S quantum dots/reduced graphene oxide (ZAIS QDs/RGO) heterojunctions. The developed heterojunctions were characterized for structural characteristics, morphology, and photocatalytic performance, while varying the content of RGO. We observed that photocatalytic hydrogen production reached a maximum at an RGO content of 30 μL (342.34 µmol g−1 h−1), surpassing that of pure ZAIS QDs (110.38 µmol g−1 h−1) by 3.1 times, while maintaining excellent stability. To understand this enhancement, we performed time-resolved fluorescence and electrochemical impedance spectroscopy. The fluorescence lifetime of RGO loaded at 30 μL (417.76 ns) was significantly higher than that of pure ZAIS QDs (294.10 ns) and had the fastest charge transfer, which can be attributed to the charge transfer and storage capacity of RGO to extend the lifetime of photogenerated carriers and improve the charge separation efficiency. This study offers a simple synthesis method for constructing 0D/2D QDs/RGO heterojunction structures and provides a valuable reference for further enhancing the activity and stability of I-III-VI sulfide QDs.
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