Significantly Increased Specific Discharge Capacitance at Carbon Fibers Created via Architected Ultramicropores.

Carbon is commonly used as an electrode material for supercapacitors operating on an electrical double-layer energy storage mechanism. However, the low specific capacitance limits its application. Increasing the specific surface area is by far the most common expansion method, and surprisingly, they are not always positively correlated. The overmuch specific surface will show the characteristics of nanoconfinement, and the potential synergistic enhancement mechanism of various key parameters is still controversial. In this work, carbon fiber electrodes with different ultramicropore structures were designed in order to improve the utilization rate and the discharge capacitance. It has been found that when the ultramicropore entrance's surface is too small, it will lead to the decrease of the external charge of the pore transport channel, and then, the selectivity of the opposite ions will decrease. The numerical simulation based on Poisson and Nernst-Planck equations also indicates that ions have difficulty diffusing into the micropores when their entrance surface decreases. Surface properties within the nanocontainment space become critical factors influencing ion transport and adsorption. The specific discharge capacitance of carbon fiber is increased from 3 to 1430 mF cm-2.

Archimedean Spirals with Controllable Chirality: Disk Substrate-Mediated Solution Assembly of Rod-Coil Block Copolymers.

Spirals are common in nature; however, they are rarely observed in polymer self-assembly systems, and the formation mechanism is not well understood. Herein, we report the formation of two-dimensional (2D) spiral patterns via microdisk substrate-mediated solution self-assembly of polypeptide-based rod-coil block copolymers. The spiral pattern consists of multiple strands assembled from the block copolymers, and two central points are observed. The spirals fit well with the Archimedean spiral model, and their chirality is dependent on the chirality of the polypeptide blocks. As revealed by a combination of experiments and theoretical simulations, these spirals are induced by an interplay of the parallel ordering tendency of the strands and circular confinement of the microdisks. This work presents the first example regarding substrate-mediated self-assembly of block copolymers into spirals. The gained information could not only enhance our understanding of natural spirals but also assist in both the controllable preparations and applications of spiral nanostructures.

Probing nanoscale structural response of collagen fibril in human Achilles tendon during loading using in situ SAXS.

The specific viscoelastic mechanical properties of the human Achilles tendon are strongly dependent on the structural characteristics of collagen. Although research on the deformation mechanisms of the Achilles tendon in various animals is extensive, understanding of these mechanisms in the human Achilles tendon remains largely empirical and macroscopic. In this work, the evolution of D-space, orientation, and average length of voids between fibers are investigated during the stretching using SAXS techniques. Initially, the void length increases marginally, while the misorientation breadth decreased rapidly as the D-space steadily increased. In the second region, D-space and the void length increase sharply under rising stress, even though misorientation width decreased. During the third region, the increases in void length and D-space decelerate, but the misorientation width widens, suggesting the onset of irreversible microscopic fibril failure in the Achilles tendon. In the final region, the fibers undergo macroscopic failure, with D-space and void length returning to their initial states. The macroscopic alterations are elucidated by the nanoscale structural responses, providing a fundamental understanding of the mechanisms driving the complex biomechanics, tissue structural organization, and Achilles tendon regeneration.

Modulating charge oriented accumulation via interfacial chemical-bond on In2O3/Bi2MoO6 heterostructures for photocatalytic nitrogen fixation.

Photocatalytic nitrogen fixation presents an eco-friendly approach to converting atmospheric nitrogen into ammonia (NH3), but the process faces challenges due to rapid interface charge recombination. Here, we report an innovative charge transfer and oriented accumulation strategy using an In-O-Mo bond-modulated S-scheme heterostructure composed of In2O3/Bi2MoO6 (In/BMO) synthesized using a simple electrostatic assembly. The unique interfacial arrangement with optimal photocatalyst configuration (3 % In/BMO) enabled enhanced photogenerated electron separation and transfer, leading to a remarkable nitrogen fixation rate of approximately 150.9 µmol·gcat-1·h-1 under visible light irradiation. The performance of the photocatalyst was 9-fold and 27-fold higher than that of its pristine components, Bi2MoO6 and In2O3, respectively. The experimental and theoretical evaluation deemed interfacial In-O-Mo bonds crucial for rapid transfer and charge-oriented accumulation. Whereas the generated internal electric field drove the spatial separation and transfer of photo-generated electrons and holes, significantly enhancing the photocatalytic N2-to-NH3 conversion efficiency. The proposed work lays the foundation for designing S-scheme heterostructures with highly efficient interfacial bonds, offering a promising avenue for substantial improvements in photocatalytic nitrogen fixation.

Efficient Dual Mechanisms Boost the Efficiency of Ternary Solar Cells with Two Compatible Polymer Donors to Exceed 19.

Ternary strategyopens a simple avenue to improve the power conversion efficiency (PCE) of organic solar cells (OSCs). The introduction of wide bandgap polymer donors (PDs) as third component canbetter utilize sunlight and improve the mechanical and thermal stability of active layer. However, efficient ternary OSCs (TOSCs) with two PDs are rarely reported due to inferior compatibility and shortage of efficient PDs match with acceptors. Herein, two PDs-(PBB-F and PBB-Cl) are adopted in the dual-PDs ternary systems to explore the underlying mechanisms and improve their photovoltaic performance. The findings demonstrate that the third components exhibit excellent miscibility with PM6 and are embedded in the host donor to form alloy-like phase. A more profound mechanism for enhancing efficiency through dual mechanisms, that are the guest energy transfer to PM6 and charge transport at the donor/acceptor interface, has been proposed. Consequently, the PM6:PBB-Cl:BTP-eC9 TOSCs achieve PCE of over 19%. Furthermore, the TOSCs exhibit better thermal stability than that of binary OSCs due to the reduction in spatial site resistance resulting from a more tightly entangled long-chain structure. This work not only provides an effective approach to fabricate high-performance TOSCs, but also demonstrates the importance of developing dual compatible PD materials.

Impacts of hyperthermic chemotherapeutic agent on cytotoxicity, chemoresistance-related proteins and PD-L1 expression in human gastric cancer cells.

Objective: Gastric cancer with peritoneal metastasis is considered to be final stage gastric cancer. One current treatment approach for this condition is combined cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (HIPEC). However, the therapeutic mechanisms of HIPEC remain largely undescribed. Method: In order to assess the cellular effects of HIPEC in vitro, we treated AGS human gastric adenocarcinoma cells with or without 5-fluorouracil (5-Fu) at 37 °C or at 43 °C (hyperthermic temperature) for 1 h followed by incubation at 37 °C for 23 h. The impacts of hyperthermia/5-Fu on apoptosis, cell survival signals, oxidative stress, chemoresistance-related proteins and programmed death-ligand 1 (PD-L1) expression were measured. Results: Our results showed that hyperthermia potentiates 5-Fu-mediated cytotoxicity in AGS cells. Furthermore, the combination of 5-Fu and hyperthermia reduces levels of both phosphorylated STAT3 and STAT3, while increasing the levels of phosphorylated Akt and ERK. In addition, 5-Fu/hyperthermia enhances reactive oxygen species and suppresses superoxide dismutase 1. Chemoresistance-related proteins, such as multidrug resistance 1 and thymidylate synthase, are also suppressed by 5-Fu/hyperthermia. Interestingly, hyperthermia enhances 5-Fu-mediated induction of glycosylated PD-L1, but 5-Fu-mediated upregulation of PD-L1 surface expression is prevented by hyperthermia. Conclusion: Taken together, our findings provide insights that may aid in the development of novel therapeutic strategies and enhanced therapeutic efficacy of HIPEC.

Double metals sites synergistically enhanced photocatalytic N2 fixation performance over Bi24O31Br10@Bi/Ti3C2Tx Ohm junctions.

At present, it is a research hotspot to realize green synthetic ammonia by using solar energy. Exploring cheap and efficient co-catalysts for enhancing the performance of photocatalysts is a challenge in the field of energy conversion. In order to boost the charge separation/transfer of the photocatalyst and widen the visible light absorption, Bi24O31Br10@Bi/Ti3C2Tx with double Ohm junction is successfully fabricated by in situ growth of metal Bi and loading Ti3C2Tx MXene on the surface of Bi24O31Br10. The dual active sites of Bi and Ti3C2Tx MXene not only broaden the light adsorption of Bi24O31Br10 but also serve as excellent 'electronic receptor' for synergically enhancing the separation/transfer efficiency of photogenerated electrons/holes. Meanwhile, temperature programmed desorption (TPD) result revealed that MXene and Bi can promote N2 adsorption/activation and NH3 desorption over Bi24O31Br10@Bi/Ti3C2Tx. As a result, under mild conditions and without the presence of hole scavenger, the ammonia synthesis efficiency of Bi24O31Br10@Bi/Ti3C2Tx-20 % reached 53.86 µmol g-1cat for three hours which is 3.2 and 53.8 times of Bi24O31Br10 and Ti3C2Tx, respectively. This study offers a novel scheme for the construction of photocatalytic systems and demonstrates Ti3C2Tx MXene and metal Bi as a promising and cheap co-catalyst.

Small-Angle X-ray Scattering for PEGylated Liposomal Doxorubicin Drugs: An Analytical Model Comparison Study.

Liposomal delivery systems are recognized as efficient and safe platforms for chemotherapeutic agents, with doxorubicin-loaded liposomes being the most representative nanopharmaceuticals. Characterizing the structure of liposomal nanomedicines in high spatial and temporal resolution is critical to analyze and evaluate their stability and efficacy. Small-angle X-ray scattering (SAXS) is a powerful tool increasingly used to investigate liposomal delivery systems. In this study, we chose a Doxil-like PEGylated liposomal doxorubicin (PLD) as an example and characterized the liposomal drug structure using synchrotron SAXS. Classical analytical models, including the spherical-shell or flat-slab geometries with Gaussian or uniform electron density profiles, were used to model the internal structure of the liposomal membrane. A cylinder model was applied to fit the scattering from the drug crystal loaded in the liposomes. The high-resolution structures of the original drug, Caelyx, and a similar research drug prepared in our laboratory were characterized using these analytical models. The structural parameters of PLDs, including the thickness of the liposomal membrane and morphology of the drug crystal, were further compared. The results demonstrated that both spherical-shell and flat-slab geometries with Gaussian electron density distribution were suitable to elucidate the structural features of the liposomal membrane under a certain range of scattering vectors, while models with uniform electron density distribution exhibited poor fitting performance. This study highlights the technical features of SAXS, which provides structural information at the nanoscale for liposomal drugs. The demonstrated methods are reliable and easy-to-use for the structural analysis of liposomal drugs, which are helpful for a broader application of SAXS in the production and regulation of nanopharmaceuticals.

NiS/Cd0.6 Zn0.4 S Schottky Junction Bifunctional Photocatalyst for Sunlight-Driven Highly Selective Catalytic Oxidation of Vanillyl Alcohol Towards Vanillin Coupled with Hydrogen Evolution Reaction.

Selective oxidation of biomass-based molecules to high-value chemicals in conjunction with hydrogen evolution reaction (HER) is an innovative photocatalysis strategy. The key challenge is to design bifunctional photocatalysts with suitable band structures, which can achieve highly efficient generation of high-value chemicals and hydrogen. Herein, NiS/Cd0.6 Zn0.4 S Schottky junction bifunctional catalysts are constructed for sunlight-driven catalytic vanillyl alcohol (VAL) selective oxidation towards vanillin (VN) coupling HER. At optimal conditions, the 8% NiS/Cd0.6 Zn0.4 S photocatalyst achieves high activity of VN production (3.75 mmol g-1 h-1 ) and HER (3.84 mmol g-1 h-1 ). It also exhibits remarkable VAL conversion (66.9%), VN yield (52.1%), and selectivity (77.8%). The photocatalytic oxidation of VAL proceeds a carbon-centered radical mechanism via the cleavage of αC-H bond. Experimental results and theoretical calculations show that NiS with metallic properties enhances the electron transfer capability. Importantly, a Ni-S-Cd "electron bridge" formed at the interface of NiS/Cd0.6 Zn0.4 S further improves the separation/transfer of electrone/h+ pairs and also furnishes HER active sites due to its smaller the |ΔGH* | value, thereby resulting in a remarkably HER activity. This work sheds new light on the selective catalytic oxidation VAL to VN coupling HER, with a new pathway towards achieving its efficient HER efficiency.

Intrinsically morphological effect of perovskite BaTiO3 boosting piezocatalytic uranium extraction efficiency and mechanism investigation.

Developing a convenient, efficient and eco-friendly approach for the recovery of U(VI) ion is a key measure to solve the environmental problems arising from the utilization of nuclear energy. Herein, the high efficiency of uranium extraction is realized by the piezo property of perovskite BaTiO3, revealing the intrinsically morphological engineering effect on the piezocatalytic performance. Especially, BaTiO3 nanowires (BTO NWs) exhibit not only an excellent piezocatalytic activity with U(VI) extraction rate of 96.8% in a UO2(NO3)2 aqueous solution compared to 71.3% of BaTiO3 nanoparticles (BTO NPs), but also a promising piezocatalyst for U extraction in a real U-mining wastewater with various pH ranges. Piezo response force microscopy and finite elemental simulation show that the piezo response of BTO NWs is much higher than BTO NPs. Additionally, some factors (pH, various ions, different powers) are explored on piezocatalytic efficiency for U(VI) extraction. The results from electron spin resonance and the charge/radical capture experiments confirm that the active species (e-, •O2-, •OH) stemmed from the piezo induction of BTO NWs and BTO NPs in the piezocatalytic U(VI) reduction process. The present work reveals the structure-performance correlation during piezocatalysis and highlights the crucial role of piezocatalysis in dealing with environmental problems.

Structural Transformation by Crystal Engineering Endows Aqueous Zinc-Ion Batteries with Ultra-long Cyclability.

Manganese oxide is a promising cathode material for aqueous zinc batteries. However, its weak structural stability, low electrical conductivity, and sluggish reaction kinetics lead to rapid capacity fading. Herein, a crystal engineering strategy is proposed to construct a novel MnO2 cathode material. Both experimental results and theoretical calculations demonstrate that Al-doping plays a crucial role in phase transition and doping-superlattice structure construction, which stabilizes the structure of MnO2 cathode materials, improves conductivity, and accelerates ion diffusion dynamics. As a result, 1.98% Al-doping MnO2 (AlMO) cathode shows an incredible 15 000 cycle stability with a low capacity decay rate of 0.0014% per cycle at 4 A g-1 . Additionally, it provides superior specific capacity of 311.2 mAh g-1 at 0.1 A g-1 and excellent rate performance (145.2 mAh g-1 at 5.0 A g-1 ). To illustrate the potential of 1.98%AlMO to be applied in actual practice, flexible energy storage devices are fabricated and measured. These discoveries provide a new insight for structural transformation via crystal engineering, as well as a new avenue for the rational design of electrode material in other battery systems.

Construction of Ternary Bismuth-Based Heterojunction by Using (BiO)2 CO3 as Electron Bridge for Highly Efficient Degradation of Phenol.

Inspired by nature, it has been considered an effective approach to design artificial photosynthetic system by fabricating Z-scheme photocatalysts to eliminate environmental issues and alleviate the global energy crisis. However, the development of low cost, environment-friendly, and high-efficient photocatalysts by utilizing solar energy still confronts huge challenge. Herein, we constructed a Bi2 O3 /(BiO)2 CO3 /Bi2 MoO6 ternary heterojunction via a facile solvothermal method and calcination approach and used it as a photocatalyst for the degradation of phenol. The optimized Bi2 O3 /(BiO)2 CO3 /Bi2 MoO6 heterojunction delivers a considerable activity for phenol photodegradation with an impressive removal efficiency of 98.8 % and about total organic carbon (TOC) of 68 % within 180 min under visible-light irradiation. The excellent photocatalytic activity was ascribed to the formation of a Z-scheme heterojunction, more importantly, the presence of (BiO)2 CO3 as an electron bridge greatly shortens the migration distance of photogenerated electron from ECB of Bi2 O3 to EVB of Bi2 MoO6 , thus prolonging the lifetime of photogenerated electrons, which is verified by trapping experiments, electron spin-resonance spectroscopy (ESR) results, and density functional theory (DFT) calculations. This work provides a potential strategy to fabricate highly efficient Bi-based Z-scheme photocatalysts with wide application prospects in solar-to-fuel conversion and environmental protection.

Hybrid Cycloalkyl-Alkyl Chain-Based Symmetric/Asymmetric Acceptors with Optimized Crystal Packing and Interfacial Exciton Properties for Efficient Organic Solar Cells.

Hybrid cycloalkyl-alkyl side chains are considered a unique composite side-chain system for the construction of novel organic semiconductor materials. However, there is a lack of fundamental understanding of the variations in the single-crystal structures as well as the optoelectronic and energetic properties generated by the introduction of hybrid side chains in electron acceptors. Herein, symmetric/asymmetric acceptors (Y-C10ch and A-C10ch) bearing bilateral and unilateral 10-cyclohexyldecyl are designed, synthesized, and compared with the symmetric acceptor 2,2'-((2Z,2'Z)-((12,13-bis(2-butyloctyl)-3,9 bis(ethylhexyl)-12,13-dihydro-[1,2,5]thiadiazolo[3,4-e]thieno[2″,3″':4',5']thieno[2',3':4,5] pyrrolo[3,2-g]thieno[2',3':4,5]thieno[3,2-b]indole-2,10- diyl)bis(methanylylidene))bis(5,6-difluoro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile (L8-BO). The stepwise introduction of 10-cyclohexyldecyl side chains decreases the optical bandgap, deepens the energy level, and enables the acceptor molecules to pack closely in a regular manner. Crystallographic analysis demonstrates that the 10-cyclohexyldecyl chain endows the acceptor with a more planar skeleton and enforces more compact 3D network packing, resulting in an active layer with higher domain purity. Moreover, the 10-cyclohexyldecyl chain affects the donor/acceptor interfacial energetics and accelerates exciton dissociation, enabling a power conversion efficiency (PCE) of >18% in the 2,2'-((2Z,2'Z)-((12,13-bis(2-ethylhexyl)-3,9-diundecyl12,13-dihydro-[1,2,5]thiadiazolo[3,4-e]thieno[2″,3″':4',5']thieno[2',3':4,5]pyrrolo[3,2-g]thieno[2',3':4,5]thieno[3,2-b]indole-2,10-diyl)bis(methanylylidene))bis(5,6-difluoro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile (Y6) (PM6):A-C10ch-based organic solar cells (OSCs). Importantly, the incorporation of Y-C10ch as the third component of the PM6:L8-BO blend results in a higher PCE of 19.1%. The superior molecular packing behavior of the 10-cyclohexyldecyl side chain is highlighted here for the fabrication of high-performance OSCs.

Continuously Flow Photothermal Catalysis Efficiently CO2 Reduction Over S-Scheme 2D/0D Bi5 O7 I-OVs/Cd0.5 Zn0.5 S Heterojunction with Strong Interfacial Electric Field.

Using CO2 , water, and sunlight to produce solar fuel is a very attractive process, which can synchronously reduce carbon and convert solar energy into hydrocarbons. However, photocatalytic CO2 reduction is often limited by the low selectivity of reduction products and poor photocatalytic activity. In this study, S-scheme Bi5 O7 I-OVs/Cd0.5 Zn0.5 S (Bi5 O7 I-OVs/CZS-0.5) heterojunction with strong interfacial electric field (IEF) is prepared by in situ growth method. The performance of reduction CO2 to CO is studied by continuous flow photothermal catalytic (PTC) CO2 reduction platform. 12.5% Bi5 O7 I-OVs/CZS-0.5 shows excellent CO yield of 58.6 µmol g-1  h-1 and selectivity of 98.4%, which are 35.1 times than that of CZS-0.5 under visible light. The charge transfer path of the S-scheme through theoretical calculation (DFT), in situ irradiation Kelvin probe force microscope (ISI-KPFM) and in situ irradiation X-ray photoelectron spectroscopy (ISI-XPS) analysis, is verified. The study can provide useful guidance and reference for improving activity by oxygen vacancy induced strong IEF and the development of a continuous flow PTC CO2 reduction system.

Formation of Efficient Quasi-All-Polymer Solar Cells by Synergistic Effect of the Ternary Strategy and Solid Additives.

All-polymer solar cells (all-PSCs) have been widely studied owing to their unique mechanical flexibility and stability. However, all-PSCs have a lower efficiency than small-molecule acceptor-based PSCs. In the work, a ternary quasi-all-polymer solar cell (Q-all-PSC) using a synergy of the ternary strategy and solid additive engineering is reported. The introduction of PC71BM can not only match the energy level of the photoactive materials with an improved open circuit voltage (VOC) of the ternary devices but also enhance photon capture, which can improve short circuit current density. It is found that there is effective charge transfer between PC71BM and PY-IT, which can form an electron transport channel and promote efficient charge transport. Moreover, the introduction of PC71BM made the PM6/PY-IT/PC71BM ternary blends more crystalline while slightly reducing phase separation, resulting in a suitable domain size. Importantly, by introducing a high dielectric-constant PFBEK solid additive as the fasten matrix, the Q-all-PSC's efficiency can reach 16.42%. This method provides a new idea for future research on all-polymer solar cells.

Over 19% Efficiency Organic Solar Cells by Regulating Multidimensional Intermolecular Interactions.

Research on organic solar cells (OSCs) has progressed through material innovation and device engineering. However, well-known and ubiquitous intermolecular interactions, and particularly their synergistic effects, have received little attention. Herein, the complicated relationship between photovoltaic conversion and multidimensional intermolecular interactions in the active layers is investigated. These interactions are dually regulated by side-chain isomerization and end-cap engineering of the acceptors. The phenylalkyl featured acceptors (LA-series) exhibit stronger crystallinity with preferential face-on interactions relative to the alkylphenyl attached isomers (ITIC-series). In addition, the PM6 and LA-series acceptors exhibit moderate donor/acceptor interactions compared to those of the strongly interacting PM6/ITIC-series pairs, which helps to enhance phase separation and charge transport. Consequently, the output efficiencies of all LA series acceptors are over 14%. Moreover, LA-series acceptors show appropriate compatibility, host/guest interactions, and crystallinity relationships with BTP-eC9, thereby leading to uniform and well-organized "alloy-like" mixed phases. In particular, the highly crystalline LA23 further optimizes multiple interactions and ternary microstructures, which results in a high efficiency of 19.12%. Thus, these results highlight the importance of multidimensional intermolecular interactions in the photovoltaic performance of OSCs.

Plate-on-plate structured MoS2/Cd0.6Zn0.4S Z-scheme heterostructure with enhanced photocatalytic hydrogen production activity via hole sacrificial agent synchronously strengthen half-reactions.

The practicable technology for producing hydrogen energy was mainly photocatalytic water splitting. Recently, heterostructural photocatalysts have attracted much attention due to its unique band structures and interfacial interactions. Herein, plate-on-plate MoS2/Cd0.6Zn0.4S heterostructure was rationally designed and fabricated by a simple strategy. It was revealed that Zn-doping content in the Cd0.6Zn0.4S solid solution as well as the mass ratio of MoS2 in the MoS2/Cd0.6Zn0.4S heterostructure can significantly affect the photocatalytic hydrogen evolution reaction (HER) activity. Especially, when Zn doping content is 40 % and the mass ratio of MoS2 is approximately 0.8 % (0.8 % MoS2/Cd0.6Zn0.4S), it exhibits the highest hydrogen production (47.68 µmol·g-1 at 2.5 h) without sacrificial agents. When Na2S/Na2SO3 is employed as sacrificial agent, its HER activity reaches 13466.50 µmol·g-1·h-1, 1.3 folds higher than Cd0.6Zn0.4S. The boosted HER activity of the Z-scheme MoS2/Cd0.6Zn0.4S heterostructure was ascribed to the greatly improved separation efficiency of photogenerated carriers. Most importantly, studies have revealed that the existence of sacrificial agents (Na2S/Na2SO3) can not only accelerate the kinetics of oxidation half reaction, but also synchronously strengthen HER half-reactions. The present work reveals a facile strategy for construction of Z-scheme heterostructures for efficient hydrogen evolution via hole sacrificial agent synchronously strengthen half-reactions.

Unraveling the Stretch-Induced Microstructural Evolution and Morphology-Stretchability Relationships of High-Performance Ternary Organic Photovoltaic Blends.

The stretchability and stretch-induced structural evolution of organic solar cells (OSCs) are pivotal for their collapsible, portable, and wearable applications, and they are mainly affected by the complex morphology of active layers. Herein, a highly ductile conjugated polymer P(NDI2OD-T2) is incorporated into the active layers of high-efficiency OSCs based on nonfullerene small molecule acceptors to simultaneously investigate the morphological, mechanical, and photovoltaic properties and structural evolution under stretching of ternary blend films with various acceptor contents. The structural robustness of the blend films is indicated by their stretch-induced structural evolution, which is monitored in real-time by a combination of in situ wide/small angle X-ray scattering. It is found that adding the soft P(NDI2OD-T2) can enhance the stretchability and structural robustness of ternary blend films by more entangled chains and tie chains to dissipate strain. Furthermore, the stretchability of the ternary blends can be superbly predicted by a 3D equivalent box model. This work provides instructive insight and guidance for designing stretchable electronics and predicting the stretchability of multicomponent blends.

Comparative study of Janus B2XY (X, Y = S, Se, Te) and F-BNBN-H monolayers for water splitting: revealing the positive and negative roles of the intrinsic dipole.

It is widely recognized that the intrinsic dipole in two-dimensional (2D) photocatalysts promotes hydrogen production during water splitting. Herein, we wonder whether the intrinsic dipole plays a negative role in water splitting. In this work, we make a comparative study of the structural, electronic, and photocatalytic properties of Janus B2XY (X, Y = S, Se, Te) and F-BNBN-H monolayers using first principles. Our theoretical results reveal that both B2XY and F-BNBN-H monolayers exhibit spatially separated conduction band minimum (CBM) and valence band maximum (VBM), as well as vacuum level differences at the opposite surfaces due to the intrinsic dipole. The F-BNBN-H monolayer has excellent redox ability for water splitting, because its CBM is located at the surface with a lower vacuum level and its VBM is distributed on the opposite surface possessing a higher vacuum level. By sharp contrast, B2XY monolayers have limited or vanishing redox ability, because their CBM is located at the surface with a higher vacuum level and their VBM is distributed on the opposite surface with a lower vacuum level. This work emphasizes the negative role of vacuum level differences of photocatalysts caused by the intrinsic dipole in water splitting.

MoS2/Ni3S2 Schottky heterojunction regulating local charge distribution for efficient urea oxidation and hydrogen evolution.

Electrocatalytic urea oxidation reaction (UOR) is a prospective method to substitute the slow oxygen evolution reaction (OER) and solve the problem of urea-rich water pollution due to the low thermodynamic voltage, but its complex six-electron oxidation process greatly impedes the overall efficiency of electrolysis. Here, density functional theory (DFT) calculations imply that the metallic Ni3S2 and semiconductive MoS2 could form Mott-Schottky catalyst because of the suitable band structure. Therefore, we synthesized MoS2/Ni3S2 electrocatalyst by a simple hydrothermal method, and studied its UOR and hydrogen evolution reaction (HER) performance. The formed MoS2/Ni3S2 Schottky heterojunction is only required 109  and 166 mV to obtain ±10 mA cm-2 for UOR and HER, respectively, showing great bifunctional catalytic activity. Moreover, the full urea electrolysis driven by MoS2/Ni3S2 delivers 10 and 100 mA cm-2 at a relatively low potential of 1.44 and 1.59 V. Comprehensive experiments and DFT calculations demonstrate that the MoS2/Ni3S2 Schottky heterojunction causes self-driven charge transfer at the interface and forms built-in electric field, which is not only benefit to reduce H* adsorption energy, but also helps to adjust the absorption and directional distribution of urea molecules, thereby promoting the activity of decomposition of water and urea. This research furnishes a tactic to devise more efficient catalysts for H2 generation and the treatment of urea-rich water pollution.