Materials with ultralong phosphorescence have wide-ranging application prospects in biological imaging, light-emitting devices, and anti-counterfeiting. Usually, molecular phosphorescence is ...significantly quenched with increasing temperature, rendering it difficult to achieve high-efficiency and ultralong room temperature phosphorescence. Herein, we spearhead this challenging effort to design thermal-quenching resistant phosphorescent materials based on an effective intermediate energy buffer and energy transfer route. Co-crystallized assembly of zero-dimensional metal halide organic-inorganic hybrids enables ultralong room temperature phosphorescence of (Ph
P)
Cd
Br
that maintains luminescent stability across a wide temperature range from 100 to 320 K (ΔT = 220 °C) with the room temperature phosphorescence quantum yield of 62.79% and lifetime of 37.85 ms, which exceeds those of other state-of-the-art systems. Therefore, this work not only describes a design for thermal-quenching-resistant luminescent materials with high efficiency, but also demonstrates an effective way to obtain intelligent systems with long-lasting room temperature phosphorescence for optical storage and logic compilation applications.
The development of bifunctional and stable non-noble metal electrocatalysts for the high-performance hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is very important and ...challenging for renewable energy. Herein, for the first time, a nickel-chromium layered double hydroxide (NiCr-LDH) nanosheet array was developed as a bifunctional electrocatalyst towards overall water splitting. By tuning different Ni/Cr ratios of LDHs, the optimized Ni
Cr
-LDH shows extraordinary HER activity with an ultralow overpotential of 138 mV at 100 mA cm
, compared with all of the reported Ni-based LDHs (NiFe-LDH, NiCo-LDH, NiMn-LDH, NiTi-LDH, NiV-LDH etc.) and even outperforming Pt/C catalysts. The small overpotential of 319 mV at 100 mA cm
for the OER and outstanding durability at 1.55 V (vs. RHE) for 30 hours can also be achieved for Ni
Cr
-LDH. Notably, a two-electrode electrolyzer with a Ni
Cr
-LDH bifunctional electrocatalyst as both the anode and the cathode can work for at least 30 hours with a cell voltage of merely 1.55 V at 10 mA cm
. Both experimental and density functional theoretical calculations show that the Cr
ions within the LDH layer serve as charge transfer sites and thus effectively boost the intrinsic electrochemical activity. Therefore, this work provides a new NiCr-LDH system as a more efficient metal hydroxide for bifunctional water splitting electrocatalyst.
The design of molecular optoelectronic materials based on fabricating polymorphs and/or co-crystals has received much recent attention in the fields of luminescence, sensors, nonlinear optics, and so ...on. If the advantages of the two crystal engineering strategies above were combined, the diversity of self-assembly fashions and the tuning of photofunctional performances would be largely extended. However, such multicomponent examples have still been very limited to date. Herein, we report the construction of luminescent polymorphic co-crystals by assembly of tris(pentafluorophenyl)borane (TPFB) with 9,10-dicyanoanthracene (DCA) and acridine (AC) as paradigms. Different stacking modes and arrangement styles based on identical building block units in polymorphic co-crystals result in adjustable crystalline morphologies and variant photophysical properties (such as fluorescence wavelength, lifetimes, and up-conversion luminescence). The optimized photoluminescence quantum yield (63.1%) and lifetime (57.1 ns) are much higher than those of the pristine assembled units. In addition, two polymorphic co-crystals (DCA@TPFB-1 and AC@TPFB-2) present prominent fluorescence polarization and optical waveguide behaviors due to the highly regulated molecular orientation. Their high one-dimensional luminescence anisotropy (0.652) and low optical waveguide loss (0.0079 dB/μm) outperform most state-of-the-art low-dimensional molecular systems and thus endow them with great opportunities for photonic materials and devices. Therefore, this work not only confirms that constructing polymorphic co-crystals can be an effective way to design new photofunctional materials for luminescence and photonic applications but also discloses a deep understanding on the relationship between variant self-assembled fashions and tunable photofunctional properties of new TPFB-based molecular materials.
Luminescent films have attracted a great amount of attention due to their unique properties and various potential applications in optical displays, sensors and switches. Due to the fast development ...of stimuli-responsive luminescent films, we believe it is timely to introduce recent advances and to promote the trends in this field. In this review, firstly, we describe several effective ways to synthesize stimuli-responsive luminescent films. The attention is then focused on the development of several important fluorescence switching systems, which are sensitive to external stimuli (such as typical physical and chemical environments). Finally, the future trends and perspectives are also briefly discussed.
Luminescent films have attracted a great amount of attention due to their unique properties and various potential applications in optical displays, sensors and switches.
Long-persistent luminescence based on purely inorganic and/or organic compounds has recently attracted much attention in a wide variety of fields including illumination, biological imaging, and ...information safety. However, simultaneously tuning the static and dynamic afterglow performance still presents a challenge. In this work, we put forward a new route of organic-doped inorganic framework to achieve wide-range and multicolor ultralong room-temperature phosphorescence (RTP). Through a facile hydrothermal method, phosphor (tetrafluoroterephthalic acid (TFTPA)) into the CdCO
(or Zn
(OH)
CO
) host matrix exhibits an excitation-dependent colorful RTP due to the formation of diverse molecular aggregations with multicentral luminescence. The RTP lifetime of the doped organic/inorganic hybrids is greatly enhanced (313 times) compared to the pristine TFTPA. The high RTP quantum yield (43.9%) and good stability guarantee their easy visualization in both ambient and extreme conditions (such as acidic/basic solutions and an oxygen environment). Further codoped inorganic ions (Mn
and Pb
) afford the hybrid materials with a novel time-resolved tunable afterglow emission, and the excitation-dependent RTP color is highly adjustable from dark blue to red, covering nearly the whole visible spectrum and outperforming the current state-of-the-art RTP materials. Therefore, this work not only describes a combined codoping and multicentral strategy to obtain statically and dynamically tunable long-persistent luminescence but also provides great opportunity for the use of organic-inorganic hybrid materials in multilevel anticounterfeiting and multicolor display applications.
Perovskite/silicon tandem solar cells are promising avenues for achieving high‐performance photovoltaics with low costs. However, the highest certified efficiency of perovskite/silicon tandem devices ...based on economically matured silicon heterojunction technology (SHJ) with fully textured wafer is only 25.2% due to incompatibility between the limitation of fabrication technology which is not compatible with the production‐line silicon wafer. Here, a molecular‐level nanotechnology is developed by designing NiOx/2PACz (2‐(9H‐carbazol‐9‐yl) ethylphosphonic acid) as an ultrathin hybrid hole transport layer (HTL) above indium tin oxide (ITO) recombination junction, to serve as a vital pivot for achieving a conformal deposition of high‐quality perovskite layer on top. The NiOx interlayer facilitates a uniform self‐assembly of 2PACz molecules onto the fully textured surface, thus avoiding direct contact between ITO and perovskite top‐cell for a minimal shunt loss. As a result of such interfacial engineering, the fully textured perovskite/silicon tandem cells obtain a certified efficiency of 28.84% on a 1.2‐cm2 masked area, which is the highest performance to date based on the fully textured, production‐line compatible SHJ. This work advances commercially promising photovoltaics with high performance and low costs by adopting a meticulously designed HTL/perovskite interface.
An ultrathin hybrid hole transporting layer employing NiOx/2‐(9H‐carbazol‐9‐yl) ethylphosphonic acid enables complete and uniform coverage on fully textured indium tin oxide (ITO)/silicon surface with pyramid structures of 2–5 µm sizes. As a result of the depleted shunt pathways between ITO and perovskite top cell, a certified record efficiency—28.84%—is achieved on perovskite/silicon tandem solar cells with fully textured, production‐line compatible bottom silicon wafers.
In current research work, highly efficient and pH-universal non-noble metal based electrocatalyst (NiVB/rGO heterostructure) towards bifunctional water splitting application is fabricated via a ...facile chemical reduction method under ambient conditions.
Display omitted
•Novel amorphous NiVB/rGO heterostructure is fabricated by a facile and easily scalable chemical reduction method.•The uniform dispersion of the NiVB nanoparticles over the ultrathin rGO nanosheets facilitates to prevent the agglomeration.•Unique architecture increases the electrochemical active surface area and accessibility to active sites.•The NiVB/rGO shows tremendous performance in a wide-range of pH for water splitting applications.
Production of hydrogen (H2) and oxygen (O2) through electrocatalytic water splitting is one of the sustainable, green and pivotal ways to accomplish the ever-increasing demands for renewable energy sources, but remains a big challenge because of the uphill reaction during overall water splitting. Herein, we develop high-performance non-noble metal electrocatalysts for pH-universal water splitting, based on nickel/vanadium boride (NiVB) nanoparticles/reduced graphene oxide (rGO) hybrid (NiVB/rGO) through a facile chemical reduction approach under ambient condition. By virtue of more exposure to surface active sites, superior electron transfer capability and strong electronic coupling, the as-prepared NiVB/rGO heterostructure needs pretty low overpotentials of 267 and 151 mV to deliver a current density of 10 mA cm−2 for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) respectively, with the corresponding Tafel slope of 44 and 88 mV dec−1 in 1.0 M KOH. Moreover, the NiVB/rGO electrocatalysts display a promising performance in a wide-pH conditions that require low overpotential of 310, 353 and 489 mV to drive a current density of 10 mA cm−2 for OER under 0.5 M KOH, 0. 05 M H2SO4 and 1.0 M phosphate buffer solution (PBS) respectively, confirming the excellent electrocatalytic performance among state-of-the-art Ni-based electrocatalysts for overall water splitting. Therefore, the interfacial tuning based on incorporation of active heterostructure may pave a new route to develop bifunctional, cost-effective and efficient electrocatalyst systems for water splitting and H2 production.
Hydrogen generation from water splitting could be an alternative way to meet increasing energy demands while also balancing the impact of energy being supplied by fossil-based fuels. The efficacy of ...water splitting strongly depends on the performance of electrocatalysts. Herein, we report a unique space-confined earth-abundant electrocatalyst having the bifunctionality of simultaneous hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), leading to high-efficiency water splitting. Outperforming Pt/C or RuO2 catalysts, this mesoscopic, space-confined, bifunctional configuration is constructed from a monolithic zeolitic imidazolate framework@layered double hydroxide (ZIF@LDH) precursor on Ni foam. Such a confinement leads to a high dispersion of ultrafine Co3O4 nanoparticles within the N-doped carbon matrix by temperature-dependent calcination of the ZIF@LDH. We demonstrate that the OER has an overpotential of 318 mV at a current density of 10 mA cm–2, while that of HER is −106 mV @ −10 mA cm–2. The voltage applied to a two-electrode cell for overall water splitting is 1.59 V to achieve a stable current density of 10 mA cm–2 while using the monolithic catalyst as both the anode and the cathode. It is anticipated that our space-confined method, which focuses on earth-abundant elements with structural integrity, may provide a novel and economically sound strategy for practical energy conversion applications.
Three one-dimensional (1D) chain polymers (1D-9HAC, 1D-Cd-9AC, and 1D-Cd-9AC-HBIM) that exhibit different intermolecular interactions and stacking patterns have been designed and synthesized. Only ...1D-Cd-9AC-HBIM with rigid (anion) and flexible (cation) units alternately arranged exhibits mechanochromic luminescence, which can be recovered through rapid solvent treatment or a self-recovery process.
A one-dimensional co-crystallized coordination polymer exhibits mechanochromic luminescence, which can be recovered through rapid solvent treatment or a self-recovery process.
Persistent luminescence has attracted great attention due to the unique applications in molecular imaging, photodynamic therapy, and information storage, among many others. However, tuning the ...dynamic persistent luminescence through molecular design and materials engineering remains a challenge. In this work, the first example of excitation‐dependent persistent luminescence in a reverse mode for smart optical materials through tailoring the excited‐state proton transfer process of metal cytosine halide hybrids is reported. This approach enables ultralong phosphorescence and thermally activated delayed fluorescence emission colors highly tuned by modulation of excitation wavelength, time evolution, and temperature, which realize multi‐mode dynamic color adjustment from green to blue or cyan to yellow‐green. At the single crystal level, the 2D excitation/space/time‐resolved optical waveguides with triple color conversion have been constructed on the organic‐metal halide microsheets, which represent a new strategy for multi‐dimensional information encryption and optical logic gate applications.
Reversed excitation‐dependent persistent luminescence can be obtained in metal cytosine halides by controlling the process of excited‐state proton transfer (ESIPT). The metal cytosine halides further exhibit multi‐mode (excitation/space/time) triple‐color luminescent conversion, which have promising applications in multi‐dimensional information encryption and photonic logic gates.
PDF
