Unraveling the Atomic Shuffles of Twinning Nucleation in Hexagonal Close-Packed Rhenium Nanocrystals.

Reining in deformation twinning is crucial for the mechanical properties of hexagonal close-packed (HCP) metals and hinges on an explicit understanding of the twinning nucleation mechanism. Unfortunately, it is often suggested rather than conclusively demonstrated that twinning nucleation can be mediated by pure atomic shuffles. Herein, by utilizing in situ high-resolution transmission electron microscopy, we have dissected the atomic shuffling mechanism during the {101̅2} twinning nucleation in rhenium nanocrystals, which revealed the emergence of an intermediate body-centered tetragonal (BCT) structure. Specifically, the double-layered prismatic planes initially shuffle into single-layered {11̅0}BCT planes; subsequently, adjacent {22̅0}BCT planes shuffle in opposite directions to form the basal planes of the twin embryo. This shuffling mechanism is further corroborated by molecular dynamic simulations. The finding provides direct evidence of shuffle-dominated twinning nucleation with atomic details that may lead to better control of this critical twinning mode in HCP metals.

[Analysis and considerations on revision of instructions for traditional Chinese medicine injections].

According to the notice on revision of the instructions for traditional Chinese medicine injections(TCMIs) issued by the National Medical Products Administration(NMPA) from January 2006 to May 2020, the revised contents in the instructions for 29 varieties involved in the notice were sorted out, and the existing problems in the instructions for TCMIs were analyzed, so as to provide the basis for dynamic revision of the instructions. It was found that the revised items of instructions for 29 varieties all involved adverse reactions, contraindications and precautions, and warnings were added for 82.76% of 29 TCMIs preparations, indicating that all the revised contents were related to safety issues. In addition, 33.33% of the drugs risks mentioned in the precautions were not indicated in the adverse reactions; 82.76% instructions did not indicate drug interactions; 17.24% instructions lacked medication notes for special populations; 48.28% instructions did not indicate traditional Chinese medicine(TCM) syndromes of the main disease; 44.83% instructions did not indicate the type and stage of indication; and 86.21% instructions did not indicate the course of treatment. It could be concluded that the instructions for TCMIs have known risks of drugs that are not fully reflected in adverse reactions and the effective information is not comprehensive. The risk control measures proposed in the precautions need to have aftereffect evaluation and there is a lack of drug interactions and medications for special populations. As an important part of the full life-cycle management of drugs, the revision of instructions for TCMIs should be continuously improved to provide the basis for safe and reasonable application of TCMIs. Based on the above problems, it is proposed that the marketing license holder as the main body of the revision of instructions should actively carry out post-marketing basic and clinical research in accordance with the characteristics of TCM, combine the updated research with the guidance of TCM theory and improve the revision level of instructions for TCMIs to provide the basis for post-marketing evaluation.

Advances in nanostructures fabricated via spray pyrolysis and their applications in energy storage and conversion.

Functional nanostructured materials have attracted great attention over the past several decades owing to their unique physical and chemical properties, while their applications have been proven to be advantageous not only in fundamental scientific areas, but also in many technological fields. Spray pyrolysis (SP), which is particularly facile, effective, highly scalable and suitable for on-line continuous production, offers significant potential for the rational design and synthesis of various functional nanostructured materials with tailorable composition and morphology. In this review, we summarize the recent progress in various functional nanostructured materials synthesized by SP and their potential applications in energy storage and conversion. After a brief introduction to the equipment, components, and working principles of the SP technique, we thoroughly describe the guidelines and strategies for designing particles with controlled morphology, composition, and interior architecture, including hollow structures, dense spheres, yolk-shell structures, core-shell structures, nanoplates, nanorods, nanowires, thin films, and various nanocomposites. Thereafter, we demonstrate their suitability for a wide range of energy storage and conversion applications, including electrode materials for rechargeable batteries, supercapacitors, highly active catalysts for hydrogen production, carbon dioxide reduction and fuel cells, and photoelectric materials for solar cells. Finally, the potential advantages and challenges of SP for the preparation of nanostructured materials are particularly emphasized and discussed, and several perspectives on future research and development directions of SP are highlighted. We expect that this continuous, one-pot, and controllable synthetic technology can serve as a reference for preparing various advanced functional materials for broader applications.

[Traditional Chinese medicine for ulcerative colitis: systematic reviews based on PRIO-harms].

This article is aimed to reevaluate the systematic reviews(Meta-analysis) of traditional Chinese medicine in the treatment of ulcerative colitis, and provide reference for evidence-based decision-making of traditional Chinese medicine(TCM). According to the preferred reporting items for overviews(preferred reporting items for overview of systematic reviews, PRIO-harms), the main Chinese and English electronic literature databases(PubMed, Cochrane Library, EMbase, CNKI, CBM, etc.) were retrieved, supplemented by manual retrieval. Systematic reviews for the treatment of ulcerative colitis with Chinese medicine up to February 2019 were included. Two researchers independently performed literature screening and data extraction. The methodology quality, reporting quality and evidence quality of the literature were evaluated by AMSTAR 2 tool, PRISMA scale and GRADE system respectively. Subgroup analysis was performed by using RevMan 5.3 software. A total of 21 systematic reviews were included, and the interventions mainly included TCM internal and external treatment, with 53 outcome indicators. The AMSTAR 2 results showed that 5 articles were of high quality, 9 of medium quality, 4 of low quality, and 3 of extremely low quality. The most problematic items were as follows: the list of excluded documents was not provided; the sources of funding for each study were not reported; and the research methods were not determined before implementation. PRISMA scale had an average score of(20.38±1.43) points, less than 22 points for 15 articles, with certain reporting defects. The GRADE system suggested that the quality of the evidence for the 30 outcome indicators was low or very low. The most important factors leading to degrading was the limitation, followed by publication bias and inconsistency. The results showed that as compared with conventional Western medicine, TCM oral or enema treatment for mild to moderate ulcerative colitis had better clinical efficacy and safety. Due to the quality limitations of the included studies, it is necessary to further strengthen the top-level design and follow the scientific research paradigm to provide a higher level of evidence for the clinical evidence-based decision-making of TCM.

C2N: an excellent catalyst for the hydrogen evolution reaction.

Based on first-principles calculations, we study the hydrogen evolution reaction (HER) on metal-free C2N and make efforts to improve its catalytic performance. At H* coverages (θ) of 3/6 and 4/6, the free energy of hydrogen adsorption (ΔGH*) is 0.10 eV and 0.07 eV, respectively, which is competitive with the precious catalyst Pt. Moreover, ΔGH* can be modulated to zero under a tensile strain, and the strength of the strain depends on the H concentration. Experimentally, it is possible to achieve a strain of around 2% through coupling C2N with graphene, and the HER performance of the hybrids would be generally enhanced. Moreover, the catalytic activity of the hybrids is tunable via electron and hole doping of graphene. In the strong H binding cases (θ = 1/6), anchoring Mn atoms into C2N exhibits a perfect catalytic property with ΔGH* of -0.04 eV. Therefore, C2N-based catalysts are expected to be easily synthesized and highly active catalysts for the HER. These findings may shed light on replacing Pt by metal-free or/and non-precious metal counterparts.

Tuning the indirect-direct band gap transition in the MoS2-xSex armchair nanotube by diameter modulation.

The application of the reported armchair transition-metal dichalcogenide (MoS2, MoTe2, MoSTe and WS2, etc.) nanotube is hindered for the optoelectronic devices due to the indirect band gap. By using first-principles calculations, the electronic structures of MoS2-xSex single-wall armchair nanotubes with respect to different diameters are investigated. The MoS2 armchair nanotube exhibits an indirect band gap as a function of nanotube diameters from 10 Å to 50 Å, whereas MoSSe and MoSe2 exhibit a surprising diameter-induced indirect-direct band gap crossover at the diameters of 25 Å and 33 Å, respectively. We also find that the optical properties of MoS2-xSex armchair nanotubes are anisotropic and strongly depend on the diameter.

Enhancing sodium ionic conductivity in tetragonal-Na3PS4 by halogen doping: a first principles investigation.

Tetragonal Na3PS4 (t-Na3PS4) has been demonstrated as a very promising candidate for a solid-state sodium-ion electrolyte with high Na ionic conductivity at ambient temperature. In this paper, we systematically investigated the Na ionic conductivity in pristine and halogen (F, Cl, Br, and I) doped tetragonal-Na3PS4 superionic conductors using first-principles calculations. The Na ionic conductivity of pristine t-Na3PS4 is calculated to be about 0.01 mS cm-1, while much higher Na ionic conductivities could be achieved by introducing Na ion vacancies via a halogen doping strategy. The calculated Na ionic conductivity of t-Na3PS4 doped with 1.56% Cl is 1.07 mS cm-1 at ambient temperature. Among different halogen-doped t-Na3PS4, Br-doped t-Na3PS4 shows the lowest activation energy and the highest Na ionic conductivity, which reaches 2.37 mS cm-1 at 300 K. The low activation energy and high Na ionic conductivity in Br-doped t-Na3PS4 are due to a relatively lower defect binding energy of the defect pair of halogen substitution and a Na ion vacancy. Our results suggest Br-doped t-Na3PS4 may serve as a very promising Na-ion solid-state superionic conductor.

Stress-Induced Cubic-to-Hexagonal Phase Transformation in Perovskite Nanothin Films.

The strong coupling between crystal structure and mechanical deformation can stabilize low-symmetry phases from high-symmetry phases or induce novel phase transformation in oxide thin films. Stress-induced structural phase transformation in oxide thin films has drawn more and more attention due to its significant influence on the functionalities of the materials. Here, we discovered experimentally a novel stress-induced cubic-to-hexagonal phase transformation in the perovskite nanothin films of barium titanate (BaTiO3) with a special thermomechanical treatment (TMT), where BaTiO3 nanothin films under various stresses are annealed at temperature of 575 °C. Both high-resolution transmission electron microscopy and Raman spectroscopy show a higher density of hexagonal phase in the perovskite thin film under higher tensile stress. Both X-ray photoelectron spectroscopy and electron energy loss spectroscopy does not detect any change in the valence state of Ti atoms, thereby excluding the mechanism of oxygen vacancy induced cubic-to-hexagonal (c-to-h) phase transformation. First-principles calculations show that the c-to-h phase transformation can be completed by lattice shear at elevated temperature, which is consistent with the experimental observation. The applied bending plus the residual tensile stress produces shear stress in the nanothin film. The thermal energy at the elevated temperature assists the shear stress to overcome the energy barriers during the c-to-h phase transformation. The stress-induced phase transformation in perovskite nanothin films with TMT provides materials scientists and engineers a novel approach to tailor nano/microstructures and properties of ferroelectric materials.

[Association between IL1R1 gene polymorphisms and childhood asthma].

OBJECTIVE: To investigate the association of two single-nucleotide polymorphisms (SNPs) in IL1R1 gene (rs1558641 and rs949963) with the susceptibility to asthma in children from Central China. METHODS: A case-control study was performed in the asthma group and the control group, consisting of 208 children with asthma and 223 normal children from Central China, respectively. The genotypes of two SNPs in IL1R1 gene, rs1558641 and rs949963, were identified using polymerase chain reaction-restriction fragment length polymorphism. The serum level of IL1R1 was determined by enzyme-linked immunosorbent assay. RESULTS: There were no significant differences in genotype and allele frequencies of rs1558641 between the asthma and control groups. In terms of rs949963, the frequencies of GG genotype and alleles were significantly higher in the asthma group than in the control group (P<0.05). The asthma group had a significantly higher serum level of IL1R1 than the control group (P=0.011). Moreover, the serum level of IL1R1 was significantly higher in patients with GG genotype than in those with AA or AG genotype for rs949963 (P=0.028). CONCLUSIONS: IL1R1 SNP rs949963 is associated with the susceptibility to asthma in children from Central China and may increase the serum expression of IL1R1.

Double hysteresis loops and large negative and positive electrocaloric effects in tetragonal ferroelectrics.

Phase field modelling and thermodynamic analysis are employed to investigate depolarization and compression induced large negative and positive electrocaloric effects (ECEs) in ferroelectric tetragonal crystalline nanoparticles. The results show that double-hysteresis loops of polarization versus electric field dominate at temperatures below the Curie temperature of the ferroelectric material, when the mechanical compression exceeds a critical value. In addition to the mechanism of pseudo-first-order phase transition (PFOPT), the double-hysteresis loops are also caused by the abrupt rise of macroscopic polarization from the abc phase to the c phase or the sudden fall of macroscopic polarization from the c phase to the abc phase when the temperature increases. This phenomenon is called the electric-field-induced-pseudo-phase transition (EFIPPT) in the present study. Similar to the two types of PFOPTs, the two types of EFIPPTs cause large negative and positive ECEs, respectively, and give the maximum absolute values of negative and positive adiabatic temperature change (ATC ΔT). The temperature associated with the maximum absolute value of negative ATC ΔT is lower than that associated with the maximum positive ATC ΔT. Both maximum absolute values of ATC ΔTs change with the variation in the magnitude of an applied electric field and depend greatly on the compression intensity.

Machine Learning-Assisted Low-Dimensional Electrocatalysts Design for Hydrogen Evolution Reaction.

Efficient electrocatalysts are crucial for hydrogen generation from electrolyzing water. Nevertheless, the conventional "trial and error" method for producing advanced electrocatalysts is not only cost-ineffective but also time-consuming and labor-intensive. Fortunately, the advancement of machine learning brings new opportunities for electrocatalysts discovery and design. By analyzing experimental and theoretical data, machine learning can effectively predict their hydrogen evolution reaction (HER) performance. This review summarizes recent developments in machine learning for low-dimensional electrocatalysts, including zero-dimension nanoparticles and nanoclusters, one-dimensional nanotubes and nanowires, two-dimensional nanosheets, as well as other electrocatalysts. In particular, the effects of descriptors and algorithms on screening low-dimensional electrocatalysts and investigating their HER performance are highlighted. Finally, the future directions and perspectives for machine learning in electrocatalysis are discussed, emphasizing the potential for machine learning to accelerate electrocatalyst discovery, optimize their performance, and provide new insights into electrocatalytic mechanisms. Overall, this work offers an in-depth understanding of the current state of machine learning in electrocatalysis and its potential for future research.

Local chemical fluctuation mediated ultra-sluggish martensitic transformation in high-entropy intermetallics.

Superelasticity associated with martensitic transformation has found a broad range of engineering applications, such as in low-temperature devices in the aerospace industry. Nevertheless, the narrow working temperature range and strong temperature sensitivity of the first-order phase transformation significantly hinder the usage of smart metallic components in many critical areas. Here, we scrutinized the phase transformation behavior and mechanical properties of multicomponent B2-structured intermetallic compounds. Strikingly, the (TiZrHfCuNi)83.3Co16.7 high-entropy intermetallics (HEIs) show superelasticity with high critical stress over 500 MPa, high fracture strength of over 2700 MPa, and small temperature sensitivity in a wide range of temperatures over 220 K. The complex sublattice occupation in these HEIs facilitates formation of nano-scaled local chemical fluctuation and then elastic confinement, which leads to an ultra-sluggish martensitic transformation. The thermal activation of the martensitic transformation was fully suppressed while the stress activation is severely retarded with an enhanced threshold stress over a wide temperature range. Moreover, the high configurational entropy also results in a small entropy change during phase transformation, consequently giving rise to the low temperature sensitivity of the superelasticity stress. Our findings may provide a new paradigm for the development of advanced superelastic alloys, and shed new insights into understanding of martensitic transformation in general.

Influence of Phase Transitions on Electrostrictive and Piezoelectric Characteristics in PMN-30PT Single Crystals.

The ultrahigh electrostrain and piezoelectric constant (d33) in relaxor piezoelectric PMN-30PT single crystals are closely related to the coexistence and transition of multiple phases at the morphotropic phase boundary (MPB). However, the key mechanisms underlying the stability of the phases and their transitions are yet to be fully understood. In this work, we undertake a systematic study of the influences of phase transitions on the electrostrictive and piezoelectric behaviors in ⟨001⟩-, ⟨011⟩-, and ⟨111⟩-oriented PMN-30PT single crystals. We first classify the various phase transitions within the quasi-MPB in electric field-temperature phase diagrams as either dominated by the electric field or by temperature. We find that the electrostrain reaches a maximum at each phase transition, especially in the electric-field-dominated transitions, whereas d33 only peaks at specific phase transitions. In particular, the electrostrain in the ⟨001⟩ crystal reaches a maximum of S = 0.52% at 55 °C under an external electric field with E = 15 kV/cm, primarily due to a joint contribution of the electric field-dominated rhombohedral-monoclinic and monoclinic-tetragonal phase transitions at the quasi-MPB. An ultrahigh d33 (∼2460 pC/N) only occurs at the rhombohedral-monoclinic phase transition in the ⟨001⟩ crystal and at the rhombohedral-orthorhombic transition in the ⟨011⟩ crystal (d33 ∼ 1500 pC/N) due to the lower energy barriers. The temperature-dominated phase transitions also contribute toward minor peaks in electrostrain and/or d33. This work provides a deeper and quantitative understanding of the microscopic mechanisms underlying electrostrictive and piezoelectric behaviors relevant for the design of high-performance materials.

Active stealth and self-positioning biomimetic vehicles achieved effective antitumor therapy.

Mesenchymal stem cells (MSCs) are recognized as promising drug delivery vehicles. However, the limitation of drug loading capacity and safety considerations are two obstacles to the further application of MSCs. Here, we report MSC membrane-coated mesoporous silica nanoparticles (MSN@M) that maintain the active stealth and self-positioning drug delivery abilities of MSCs and resolve issues related to MSCs-mediated drug delivery. MSN@M was established through uniformly integrating MSC membrane onto a mesoporous silica nanoparticle (MSN) core by sonication. Reduced clearance of phagocytes mediated by CD47 marker on MSC membrane was observed in vitro, which explained the only ~ 25% clearance rate of MSN@M compared with MSN in vivo within 24 h. MSN@M also showed stronger tumor targeting and penetration ability compared with MSN in HepG2 tumor bearing mice. Simultaneously, MSN@M exhibited strong capacity for drug loading and sustained drug release ability of MSN when loaded with doxorubicin (DOX), the drug loading of MSN@M increased ~ 5 folds compared with MSC membrane. In HepG2 xenograft mice, DOX-loaded MSN@M effectively inhibited the growth of tumors and decreased the side effects of treatment by decreasing the exposure of other tissues to DOX. Consequently, our MSN@M may serve as alternative vehicles for MSCs and provide more options for antitumor treatment.

Role of Residual Li and Oxygen Vacancies in Ni-rich Cathode Materials.

Residual Li and oxygen vacancies in Ni-rich cathode materials have a great influence on electrochemical performance, yet their role is still poorly understood. Herein, by simply adjusting the oxygen flow during the high-temperature sintering process, some Li2O can be carried into the exhaust gas and the contents of residual Li and oxygen vacancies in LiNi0.825Co0.115Mn0.06O2 cathodes can be accurately controlled. Residual Li reduces the surficial Li+ diffusion coefficient, thereby limiting the rate property of the cathode. Oxygen vacancies affect the oxygen release energy in the crystal, and the lowest oxygen release energy is found at an oxygen vacancy concentration of 8.35%, resulting in an unstable structure and thereby poor cycle performance. The Ni-rich cathode with low residual Li and oxygen vacancy contents exhibits superior capacity retention (89.55 and 77.66%) at 2C after 300 cycles between 2.7-4.3 and 2.7-4.5 V. These findings clarify the role of residual Li and oxygen vacancies in Ni-rich cathode materials and provide a simple way to obtain high-performance Ni-rich cathodes for high-energy-density Li-ion batteries.

Alkali-deficiency driven charged out-of-phase boundaries for giant electromechanical response.

Traditional strategies for improving piezoelectric properties have focused on phase boundary engineering through complex chemical alloying and phase control. Although they have been successfully employed in bulk materials, they have not been effective in thin films due to the severe deterioration in epitaxy, which is critical to film properties. Contending with the opposing effects of alloying and epitaxy in thin films has been a long-standing issue. Herein we demonstrate a new strategy in alkali niobate epitaxial films, utilizing alkali vacancies without alloying to form nanopillars enclosed with out-of-phase boundaries that can give rise to a giant electromechanical response. Both atomically resolved polarization mapping and phase field simulations show that the boundaries are strained and charged, manifesting as head-head and tail-tail polarization bound charges. Such charged boundaries produce a giant local depolarization field, which facilitates a steady polarization rotation between the matrix and nanopillars. The local elastic strain and charge manipulation at out-of-phase boundaries, demonstrated here, can be used as an effective pathway to obtain large electromechanical response with good temperature stability in similar perovskite oxides.

Nano-size porous carbon spheres as a high-capacity anode with high initial coulombic efficiency for potassium-ion batteries.

Hard carbon materials have been recognized as a promising family of anode materials for potassium ion batteries (PIBs), but their practical application is severely hindered due to the inferior initial coulombic efficiency (ICE) and low capacity. Herein, we report our findings in simultaneously improved potassium storage capacity and ICE through the design of nano-size and porous structure and the appropriate selection of electrolytes. Benefiting from the high specific surface area, stable electrode|electrolyte interface, and fast potassium ion and electron transfer, the optimized electrode exhibits a high ICE of up to 68.2% and an outstanding reversible capacity of 232.6 mA h g-1 at 200 mA g-1. In particular, superior cycling stability of 165.2 mA h g-1 at 1000 mA g-1 and 129.7 mA h g-1 at 2000 mA g-1 can be retained after 1500 cycles, respectively. Quantitative analysis reveals that this optimized structure leads to an enhanced surface-controlled contribution, resulting in fast potassiation kinetics and electronic|ionic conductivities, which are regarded as essential features for potassium storage. Our findings in this work provide an efficient strategy to significantly improve potassium storage capacity while maintaining a high ICE for hard carbon electrodes.

Reversing Interfacial Catalysis of Ambipolar WSe2 Single Crystal.

An improved understanding of the origin of the electrocatalytic activity is of importance to the rational design of highly efficient electrocatalysts for the hydrogen evolution reaction. Here, an ambipolar single-crystal tungsten diselenide (WSe2) semiconductor is employed as a model system where the conductance and carrier of WSe2 can be individually tuned by external electric fields. The field-tuned electrochemical microcell is fabricated based on the single-crystal WSe2 and the catalytic activity of the WSe2 microcell is measured versus the external electric field. Results show that WSe2 with electrons serving as the dominant carrier yields much higher activity than WSe2 with holes serving as the dominant carrier even both systems exhibit similar conductance. The catalytic activity enhancement can be characterized by the Tafel slope decrease from 138 to 104 mV per decade, while the electron area concentration increases from 0.64 × 1012 to 1.72 × 1012 cm-2. To further understand the underlying mechanism, the Gibbs free energy and charge distribution for adsorbed hydrogen on WSe2 versus the area charge concentration is systematically computed, which is in line with experiments. This comprehensive study not only sheds light on the mechanism underlying the electrocatalysis processes, but also offers a strategy to achieve higher electrocatalytic activity.

Strongly Coupled MoS2 Nanocrystal/Ti3 C2 Nanosheet Hybrids Enable High-Capacity Lithium-Ion Storage.

Smart integration of transition-metal sulfides/oxides/nitrides with the conductive MXene to form hybrid materials is very promising in the development of high-performance anodes for next-generation Li-ion batteries (LIBs) owing to their advantages of high specific capacity, favorable Li+ intercalation structure, and superior conductivity. Herein, a facile route was proposed to prepare strongly coupled MoS2 nanocrystal/Ti3 C2 nanosheet hybrids through freeze-drying combined with a subsequent thermal process. The Ti3 C2 host could enhance the reaction kinetics and buffer the volume change of MoS2 at a low content (8.87 wt %). Thus, the MoS2 /Ti3 C2 hybrids could deliver high rate performance and excellent cycling durability. As such, high reversible capacities of 835.1 and 706.0 mAh g-1 could be maintained after 110 cycles at 0.5 A g-1 and 1390 cycles at 5 A g-1 , respectively, as well as an outstanding rate capability with a capacity retention over 65.8 % at 5 A g-1 . This synthetic strategy could be easily extended to synthesize other high-performance MXene-supported hybrid electrode materials.

Electronic and plasmonic phenomena at nonstoichiometric grain boundaries in metallic SrNbO3.

Grain boundaries could exhibit exceptional electronic structure and exotic properties, which are determined by a local atomic configuration and stoichiometry that differs from the bulk. However, optical and plasmonic properties at the grain boundaries in metallic oxides have rarely been discussed before. Here, we show that non-stoichiometric grain boundaries in the newly discovered metallic SrNbO3 photocatalyst show exotic electronic, optical and plasmonic phenomena in comparison to bulk. Aberration-corrected scanning transmission electron microscopy and first-principles calculations reveal that a Nb-rich grain boundary exhibits an increased carrier concentration with quasi-1D metallic conductivity, and newly induced electronic states contributing to the broad energy range of optical absorption. More importantly, dielectric function calculations reveal extended and enhanced plasmonic excitations compared with bulk SrNbO3. Our results show that non-stoichiometric grain boundaries might be utilized to control the electronic and plasmonic properties in oxide photocatalysis.