查看更多>>摘要：Lead halide perovskite solar cells (PSCs) have come closer to their commercialization because of their high power conversion efficiencies (PCEs), substantially enhanced stability, and low-cost and scalable manufacturing. However, toxic lead (Pb) as an indispensable component in high-performance PSCs remains an outstanding issue challenging the commercialization of perovskite photovoltaic technology; toxic and water-soluble lead can leak out of perovskite layers under severe weather conditions, resulting in great potential pollution to soil and underground water. It is therefore essential to develop a closed-loop management of lead from preventing Pb leakage from perovskite solar modules during the device service life to recycling Pb from end-of-life modules. Here we highlight the recent advances in the sustainable management of Pb in PSCs from the above two aspects, and provide a brief outlook for the further development of lead management in PSCs.
查看更多>>摘要：The prevalence of MXenes, two-dimensional (2D) transition metal carbides/nitrides separated from layered MAX phases, has generated much interest in exploring 2D transition metal borides during the past decade. In 2017, we first reported a new family of 2D transition metal borides as analogues to MXenes and coined a catchy name for them, MBenes. Over the last five years, MBenes have gained more and more attentions in the fields of nanomaterials, physics and chemistry. The promising future of MBenes is foreseeable since they have exhibited many intriguing properties and been widely studied for energy storage and electrocatalysis applications. However, research on MBenes is still in its infancy, with many expected properties and applications awaiting to be explored. In this review, first we made a scientific classification of 2D transition metal borides and proposed an explicit definition of MBenes: a family of 2D transition metal borides with sandwich-like structures which are derived from layered MAB phases. Then we reviewed the progress of synthesis methods, properties and applications of MBenes for energy storage and electrocatalysis. Finally, the discussions on the existing problems in experimental synthesis and theoretical calculations along with the perspectives and prospects of MBenes were presented.
查看更多>>摘要：Recently, great advances in polymerized small molecular acceptors (PSMAs) have boosted the power conversion efficiencies (PCEs) of all-polymer solar cells (all-PSCs) over the 17% milestone. However, significant research efforts have been mainly dedicated to designing narrow bandgap PSMAs by altering the building block and alkyl side chain. In this work, we report the design of novel PSMAs with wide bandgaps by incorporating a novel terminal unit without isomerization, 5-bromo-4,7-difluoro-1H-indene-1,3(2H)-dione (FFOBr). The resulting PSMAs exhibit high molar absorption coefficient over 105 M−1 cm−1, relatively wide bandgaps about 1.65 eV as well as high-lying lowest occupied molecular orbital (LUMO) energy levels of above −3.70 eV. When matching with the polymer donor JD40, both polymer acceptors can enable efficient all-PSCs with over 1.10 V open-circuit voltage (VOC) due to their high-lying LUMO energy level. Moreover, with a screened copolymerization spacer, the PFFO-Th-based blend film exhibits favorable morphology, more ordered crystallization, improved charge transport, and reduced recombination losses, which together contribute to the higher short-circuit current density and fill factor and thereby a high PCE of 10.8%. This value is one of the best with regard to PSMA-based all-polymer solar cells with VOC over 1.10 V in the reported literature. Our work shows that the terminal unit and linkage manipulation are effective strategies to develop high-performance PSMAs with controllable bandgaps.
查看更多>>摘要：Tailoring electrode–electrolyte interphases could potentially enhance the interfacial reaction for protonic ceramic fuel cells (PCFCs), and an in situ generated dense active cathode functional interlayer (CFI) via a low-cost linear current sweeping (LCS) method is developed based on the perovskite-related Sm2Ba1.33Ce0.67Cu3O9 (SBCC) cathode material. Due to the simultaneous occurrence of Ba element segregation and the densifying process at the SBCC/BZCY interface during the LCS procedure, the Ba(Zr,Ce)1−x(Sm,Y,Cu)xO3−δ (BZCSYC) phase is formed and sandwiched between two SBCC phases in the 2 μm thick CFI, promoting the protolysis to the SBCC@BZCSYC CFI–cathode interface. When assessing the SBCC cathode accompanied by the CFI based on a BaZr0.1Ce0.7Y0.2O3−δ-based single-cell, exhilarating cell performance with peak power densities (PPDs) of 1669 and 905 mW cm−2, corresponding to the interfacial polarization resistance (RP) values of 0.027 and 0.115 Ω cm2 at 700 and 600 °C, respectively, is attained. The superior cell performance, including the remarkably high PPD and the notably low RP, clearly state that SBCC is a preferential cathode alternative. The LCS technique is an advanced method to optimize the electrode interface for high-performance low-temperature PCFCs.
查看更多>>摘要：Perovskite scintillators have emerged as good candidates for next-generation X-ray detectors due to their excellent scintillation efficiency and controllable properties by compositions. However, moisture stability and large-area X-ray imaging are still major concerns. Here, we report two 0D lead-free perovskite structures with different ionic arrangements formed by co-assembling solvent molecules with perovskite ions. Different solvent molecules of hydrogen oxide (H2O) and acetonitrile (CH3CN) were self-assembled into a crystal lattice to modulate the ion arrangements of two new single crystals 4-diethylaminobenzoic acid manganese(ii) bromide hydrogen oxide ((DABA)2MnBr4·H2O) and 4-diethylaminobenzoic acid manganese(ii) bromide acetonitrile ((DABA)2MnBr4·CH3CN). The solvent co-assembled perovskite single crystal exhibits excellent moisture stability under ambient conditions for one month without any encapsulation, and is a good candidate for a low-cost and high-performance scintillator. The multiple supramolecular interactions within the two single crystals offer efficient driving forces for self-assembly, and the excitons are better confined in the (DABA)2MnBr4·H2O crystals than that in (DABA)2MnBr4·CH3CN crystals, resulting in a higher photoluminescence (PL) quantum yield of 51%. The light yield of (DABA)2MnBr4·H2O to 120 keV can reach 28 333 photons MeV−1. In addition, constructed strong hydrogen bonds in (DABA)2MnBr4·H2O ensure good capability to suppress thermal PL quenching due to the reduced electron-phonon interactions. Large-area scintillators with a dimension size of 2.4 cm × 3.0 cm exhibit comparable X-ray imaging capability with spatial resolutions up to 5.0 lp mm−1, providing a new design route for the perovskite scintillator family.
查看更多>>摘要：Solubility prediction is important in developing high-performance optoelectronic materials for organic solar cells, and can assist the synthetic route and chemical process design of optoelectronic materials, and control the morphology of bulk-heterojunctions. Here we report a successful approach that can effectively predict the solubility of optoelectronic materials in any solvents by using a combination of machine learning and quantum chemistry descriptors. Temperature combined with quantum chemistry calculated molecular vdW surface area (area), positive electrostatic potential (ESP) variance (σ+2) and negative ESP variance (σ−2) were used as a small set of descriptors containing only 7 bits of data. It is the smallest set of descriptors currently used and shows good predictive performance to predict the solubility. This small set of descriptors enables us to predict the solubility of any small molecule in various solvents with a small number of quantum chemical calculations. The solubility of PCBM and Y6 in 42 common solvents used in organic chemistry was predicted, and 10 solvents with the highest solubility are screened out from the dataset. This model can be applied to other small-molecule systems to rapidly predict their solubility in any solvent and provide an important parameter for designing promising high-performance optoelectronic materials for organic solar cells.
查看更多>>摘要：The rational design and preparation of cost-effective, efficient and durable metal carbon nanomaterials for the oxygen evolution reaction (OER) is of great urgency. Herein, we report a high-performance OER electrocatalyst consisting of bimetallic FeNi3 nanoparticles encapsulated in hierarchical carbon nanomaterial, denoted as FeNi3@NCNT. Through a stepwise strategy, hollow carbon nanorods with abundant carbon nanotubes can be successfully calcined from rod-like NiOF-1-Fe, which are hydrolyzed to the initial NiOF-1 by Fe(iii) ions. The optimal FeNi3@NCNT catalyst exhibits an excellent electrochemical performance with a low overpotential of 264 mV at 10 mA cm−2, a Tafel slope of 58.5 mV dec−1, and a robust stability over 10 hours compared to the control samples. This enhanced OER arises from the unique hollow nanorod modified with a nanotube structure, a large surface area, a rich nitrogen content, and the synergistic effect between Ni and Fe species. Indeed, it is catalyzed by in situ generated Fe coupling with NiOOH in carbon nanotubes, which is validated by the subsequent theoretical calculations. This work enables insights into the mechanism of Fe-doped Ni oxyhydroxides for efficient OER and adds to the increasing understanding of the design and synthesis of novel catalysts for efficient energy conversion and storage.
查看更多>>摘要：The instability caused by coking and catalyst sintering during the dry reforming of methane (DRM) is a major obstacle to their commercialization. Herein, Pt/La2O3 exhibits high yield of syngas and satisfactory durability of at least 200 h during the DRM reaction under focused light illumination without external heating, and no obvious aggregation occurs to Pt nanoparticles on Pt/La2O3. The H2 production rate of 1284.5 mmol gcat−1 h−1 and the selectivity of ∼0.89 in photothermocatalysis are 3.0 and 2.1 folds of those in the thermocatalysis at the same temperature (700 °C), respectively. Light-excited hot electrons and more oxygen vacancies accelerate the spontaneous desorption of H2 and the activation and dissociation of CH4 and CO2 to improve the catalytic performance, which together with the strong Pt-support interaction contributes to the reaction stability. The stable catalyst design can be extended to other harsh reactions, offering great potential for industrial applications.
查看更多>>摘要：Developing a sacrificial agent-free Zn1−xCdxS-based photocatalyst for efficient photocatalytic overall water splitting (POWS) is economical and eco-friendly but a challenging task. Herein, we synthesize a phosphorus (PO) protection layer and non-precious FexCoyNizP and MnOa cocatalysts on Zn0.4Cd0.6S by a safe and energy-saving two-step photochemical strategy. The prepared Zn0.4Cd0.6S/PO/FexCoyNizPi–MnOa photocatalyst displays average hydrogen and oxygen evolution rates of ∼1.14 mmol h−1 g−1 and ∼0.54 mmol h−1 g−1 in POWS, respectively, where FexCoyNizP and MnOa act as the photogenerated electron and hole acceptors and provide the active sites for the two reactions. The superior POWS performance was maintained for 12 hours without any obvious attenuation. Moreover, photocatalytic partial water splitting (PPWS) is induced by the oxidation of NaH2PO2 during the photochemical synthesis process, yielding hydrogen evolution rates of 7.22 mmol h−1 g−1 and 5.90 mmol h−1 g−1, respectively. By integrating the two-step photochemical synthesis and POWS process (PPWS → PPWS → POWS), we obtain a total H2 yield of about 4.85 mmol under 17 h visible light irradiation, which corresponds to an average H2 evolution rate of 0.29 mmol h−1. This work develops a safe and energy-saving photochemical synthesis strategy for Zn1−xCdxS-based photocatalysts, which not only exhibits excellent POWS performance but opens an avenue for the tandem application of PPWS and POWS to achieve a high H2 total yield for solar-energy conversion.
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