All-Inorganic Perovskite NiTiO3 /Cs3 Sb2 I9 Heterostructure for Photocatalytic CO2 Reduction to CH4 with High Selectivity.

Developing efficient and stable halide perovskite-based photocatalysts for highly selectivity reduction CO2 to valuable fuels remains a significant challenge due to their intrinsic instability. Herein, a novel heterostructure featuring 2D Cs3 Sb2 I9 nanosheets on a 3D flower-like mesoporous NiTiO3 framework using a top-down stepwise membrane fabrication technique is constructed. The unique bilayer heterostructure formed on the 3D mesoporous framework endowed NiTiO3 /Cs3 Sb2 I9 with sufficient and close interface contact, minimizing charge transport distance, and effectively promoting the charge transfer at the interface, thus improving the reaction efficiency of the catalyst surface. As revealed by characterization and calculation, the coupling of Cs3 Sb2 I9 with NiTiO3 facilitates the hydrogenation process during catalytic, directing reaction intermediates toward highly selective CH4 production. Furthermore, the van der Waals forces inherent in the 3D/2D heterostructure with face-to-face contact provide superior stability, ensuring the efficient realization of photocatalytic CO2 reduction to CH4 . Consequently, the optimized 3D/2D NiTiO3 /Cs3 Sb2 I9 heterostructure demonstrates an impressive CH4 yield of 43.4 µmol g-1  h-1 with a selectivity of up to 88.6%, surpassing most reported perovskite-based photocatalysts to date. This investigation contributes to overcoming the challenges of commercializing perovskite-based photocatalysts and paves the way for the development of sustainable and efficient CO2 conversion technologies.

Achieving High Responsivity and Detectivity in a Quantum-Dot-in-Perovskite Photodetector.

This work reports on quantum dots (QDs) in perovskite photodetectors showing high optoelectronic performance via quantum-dot-assisted charge transmission. The self-powered broad-band photodetector constructed with SnS QDs in FAPb0.5Sn0.5I3 perovskite can capture incoming optical signals directly at zero bias. The QDs-in-perovskite photodetector exhibits a high sensitivity in the wavelength range from 300 to 1000 nm. Its responsivity at 850 nm reaches 521.7 mA W-1, and a high specific detectivity of 2.57 × 1012 jones can be achieved, which is well beyond the level of previous self-powered broad-band photodetectors. The capability of quantum-dot-in-perovskite photodetectors as data receivers has been further demonstrated in a visible-light communication application.

Performance of a polymerization-based electrochemically assisted persulfate process on a real coking wastewater treatment.

Industrial wastewater should be treated with caution due to its potential environmental risks. In this study, a polymerization-based cathode/Fe3+/peroxydisulfate (PDS) process was employed for the first time to treat a raw coking wastewater, which can achieve simultaneous organics abatement and recovery by converting organic contaminants into separable solid organic-polymers. The results confirm that several dominant organic contaminants in coking wastewater such as phenol, cresols, quinoline and indole can be induced to polymerize by self-coupling or cross-coupling. The total chemical oxygen demand (COD) abatement from coking wastewater is 46.8% and the separable organic-polymer formed from organic contaminants accounts for 62.8% of the abated COD. Dissolved organic carbon (DOC) abatement of 41.9% is achieved with about 89% less PDS consumption than conventional degradation-based process. Operating conditions such as PDS concentration, Fe3+ concentration and current density can affect the COD/DOC abatement and organic-polymer yield by regulating the generation of reactive radicals. ESI-MS result shows that some organic-polymers are substituted by inorganic ions such as Cl-, Br-, I-, NH4+, SCN- and CN-, suggesting that these inorganic ions may be involved in the polymerization. The specific consumption of this coking wastewater treatment is 27 kWh/kg COD and 95 kWh/kg DOC. The values are much lower than those of the degradation-based processes in treating the same coking wastewater, and also are lower than those of most processes previously reported for coking wastewater treatment.

Single-Crystal Nanowire Cesium Tin Triiodide Perovskite Solar Cell.

This work reports for the first time a highly efficient single-crystal cesium tin triiodide (CsSnI3 ) perovskite nanowire solar cell. With a perfect lattice structure, low carrier trap density (≈5 × 1010 cm-3 ), long carrier lifetime (46.7 ns), and excellent carrier mobility (>600 cm2 V-1 s-1 ), single-crystal CsSnI3 perovskite nanowires enable a very attractive feature for flexible perovskite photovoltaics to power active micro-scale electronic devices. Using CsSnI3 single-crystal nanowire in conjunction with highly conductive wide bandgap semiconductors as front-surface-field layers, an unprecedented efficiency of 11.7% under AM 1.5G illumination is achieved. This work demonstrates the feasibility of all-inorganic tin-based perovskite solar cells via crystallinity and device-structure improvement for the high-performance, and thus paves the way for the energy supply to flexible wearable devices in the future.

Isoprenylated Flavonoids and 2-Arylbenzofurans from the Root Bark of Morus alba L. and Their Cytotoxic Activity against HGC27 Cancer Cells.

Three new compounds (1, 11, and 12), together with 32 known ones, were isolated from the root bark of Morus alba L. using various chromatographic methods. The structures of the undescribed compounds were elucidated based on 1D, 2D NMR, and HRESIMS dataanalysis, while the known ones were identified by comparison of their spectroscopic data with those reported in the literature. All the isolates were evaluated for their cytotoxic activities against human gastric cancer HGC27 cells by CCK-8 assay. Among them, compounds 5, 8, 10, and 30 exhibited cytotoxic activities on HGC27 cells with IC50 values of 33.76 ± 2.64 µM, 28.94 ± 0.72 µM, 6.08 ± 0.34 µM, and 10.24 ± 0.89 µM, respectively. Furthermore, compound 10 was confirmed to reduce proliferation ability, increase apoptosis rate, and inhibit cell migration pathway by annexin V/PI double staining experiment, transwell experiment, and Western blot analysis.

Effect of a Cocatalyst on a Photoanode in Water Splitting: A Study of Scanning Electrochemical Microscopy.

With a proper band gap of ∼2.4 eV for solar light absorption and suitable valence band edge position for oxygen evolution, scheelite-monoclinic bismuth vanadate (BiVO4) has become one of the most attractive photocatalysts for efficient visible-light-driven photoelectrochemical (PEC) water splitting. Several studies have indicated that surface modification of BiVO4 with a cocatalyst such as NiFe layered double hydroxide (LDH) can significantly increase the PEC water splitting performance of the catalyst. Herein, we experimentally investigated the charge transfer dynamics and charge carrier recombination processes by scanning electrochemical microscopy (SECM) with the feedback mode on the surface of BiVO4 and BiVO4/NiFe-LDH as model samples. The ratio of rate constants for photogenerated hole (kh+0) to electron (ke-0) via the photocatalyst of BiVO4/NiFe-LDH reacting with the redox couple is found to be five times larger than that of BiVO4 under illumination. In this case, the ratio of the rate constants kh+0/ke-0 stands for the interfacial charge recombination process. This implies the cocatalyst NiFe-LDH suppresses the electron back transfer greatly and finally reduces the surface recombination. Control experiments with cocatalysts CoPi and RuOx onto BiVO4 further verify this conclusion. Therefore, the SECM characterization allows us to make an overall analysis on the function of cocatalysts in the PEC water splitting system.

Steroidal alkaloids from the bulbs of Fritillaria pallidiflora Schrenk and their anti-inflammatory activity.

Steroidal alkaloids (1-11), including one new 24-hydroxylated cevanine-type steroidal alkaloid, named yibeinone F (1), were isolated from the bulbs of Fritillaria pallidiflora Schrenk. Their structures were elucidated by analyses of extensive spectroscopic data and comparison of the NMR data with those reported previously, and the structures of compounds 1, 7 and 11 were further confirmed by X-ray single crystal diffraction analyses. The anti-inflammatory effects of all the isolated alkaloids were evaluated in LPS-activated RAW264.7 macrophages. Among them, compounds 9 (stenanzine) and 10 (hapepunine) showed significant inhibitory effects against LPS-induced NO production with IC50 values of 8.04 µM and 20.85 µM, respectively. Furthermore, compound 9 effectively inhibited the release of cytokines such as interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and prostaglandin E2 (PGE2), and suppressed the protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX2) in LPS-stimulated RAW264.7 cells. Further experiments revealed the underlying mechanism that 9 blocked LPS-induced phosphorylation and degradation of inhibitor-α of nuclear transcription factor κB (IκBα) and c-Jun N-terminal kinase (JNK) in RAW264.7 cells. Taken together, compound 9 may be a valuable candidate for the treatment of inflammatory diseases.

Surfactant-Modified Hydrothermal Synthesis of Ca-Doped CuCoO2 Nanosheets with Abundant Active Sites for Enhanced Electrocatalytic Oxygen Evolution.

It is urgent to explore cost-effective, high-efficiency, and durable electrocatalysts for electrochemical water splitting due to the rapidly increasing energy consumption. In this work, we successfully synthesize Ca-doped CuCoO2 nanosheets (CCCO-P NSs) with different Ca2+ dopants (such as 3, 5, and 10 atom %) by a surfactant-modified hydrothermal reaction with polyvinylpyrrolidone (PVP) addition. The oxygen evolution reaction (OER) performances of these CCCO-P NSs in 1.0 M KOH are investigated. An optimal nickel foam supported CCCO-P2 NSs (Ni@CCCO-P2, 5 atom % Ca-doped) electrode requires low overpotential of 470 mV to afford the current density of 10 mA cm-2 and small Tafel slope of 96.5 mV dec-1. Furthermore, the Ni@CCCO-P2 electrode displays outstanding long-term stability during the galvanostatic OER electrolysis for 18 h with a little degradation of 32 mV. The improvement of OER performances for CCCO-P2 NSs could be attributed to their higher active surface area, more active sites (Co vacancies defect and Co3+/Co4+ redox pairs), and higher electrical conductivity. This work highlights the joint effect of surfactant and Ca doping for preparing CuCoO2 with nanosheet-like morphology and porous crystal structure, which is favorable for enhancing their OER performance.

Nanostructured Ni2SeS on Porous-Carbon Skeletons as Highly Efficient Electrocatalyst for Hydrogen Evolution in Acidic Medium.

Nickel dichalcogenides have received extensive attention as promising noble-metal-free nanocatalysts for a hydrogen evolution reaction. Nonetheless, their catalytic performance is restricted by the sluggish reaction kinetics, limited exposed active sites, and poor conductivity. In this work, we report on an effective strategy to solve those problems by using an as-designed new porous-C/Ni2SeS nanocatalyst with the Ni2SeS nanostubs anchored on with porous-carbon skeletons process. On the basis of three advantages, as the enhancement of the intrinsic activity using the ternary sulfoselenide, increased number of exposed active sites due to the 3D hollow substrate, and increased conductivity caused by porous-carbon skeletons, the resulting porous-C/Ni2SeS requires an overpotential of only 121 mV at a current density of 10 mA cm-2 with a Tafel slope of 78 mV dec-1 for hydrogen evolution in acidic media and a good long-term stability. Density functional theory calculations also show that the Gibbs free energy of hydrogen adsorption of the Ni2SeS was -0.23 eV, which not only is close to the ideal value (0 eV) and Pt reference (-0.09 eV) but also is lower than those of NiS2 and NiSe2; large electrical states exist in the vicinity of the Fermi level, which further improves its electrocatalytic performance. This work provides new insights into the rational design of ternary dichalcogenides and hollow structure materials for practical applications in HER catalysis and energy fields.

Two New Cucurbitane Glycosides from the Fruits of Siraitia grosvenori.

Two novel cucurbitane glycosides, named as 11-oxomogroside III A1 and 7ß-methoxy-mogroside V, along with sixteen known ones were isolated from the fruits of Siraitia grosvenori SWINGLE. The structures of the new compounds were characterized by chemical and extensive spectral methods.

Highly Efficient Perovskite Solar Cells with Gradient Bilayer Electron Transport Materials.

Electron transport layers (ETLs) with suitable energy level alignment for facilitating charge carrier transport as well as electron extraction are essential for planar heterojunction perovskite solar cells (PSCs) to achieve high open-circuit voltage ( VOC) and short-circuit current. Herein we systematically investigate band offset between ETL and perovskite absorber by tuning F doping level in SnO2 nanocrystal. We demonstrate that gradual substitution of F- into the SnO2 ETL can effectively reduce the band offset and result in a substantial increase in device VOC. Consequently, a power conversion efficiency of 20.2% with VOC of 1.13 V can be achieved under AM 1.5 G illumination for planar heterojunction PSCs using F-doped SnO2 bilayer ETL. Our finding provides a simple pathway to tailor ETL/perovskite band offset to increase built-in electric field of planar heterojunction PSCs for maximizing VOC and charge collection simultaneously.

High Efficiency Non-fullerene Organic Tandem Photovoltaics Based on Ternary Blend Subcells.

The application of tandem structure that integrates multiple subcells into one device is a promising way to realize high efficiency organic solar cells. However, current-matching among different subcells remains as the main challenge for organic tandem photovoltaics. Here, we provide a facile approach to achieve a good current matching via engineering the chemical composition of non-fullerene ternary blend subcells. For the front subcell, a ternary blend of PDBT-T1:TPH-Se:ITIC is selected due to its good thermal stability. The amorphous nature of TPH-Se can sufficiently suppress the unfavorable phase separation of blends during the heat treatment, enabling a sintering in the fabrication of high quality interconnecting layer. A double-junction tandem device is fabricated with a rear subcell consisting of PBDB-T:ITIC. After the optimization of the chemical composition of the front subcell, the power conversion efficiency (PCE) of double-junction tandem device increased from 10.6% using PDBT-T1:TPH-Se binary front subcell to 11.5% using PDBT-T1:TPH-Se:ITIC (1:0.9:0.1) ternary front subcell due to better current matching. In order to further enhance the light absorption in the near-infrared region, a third junction PBDTTT-EFT:IEICO-4F is introduced. The champion cell of triple-junction non-fullerene tandem solar cell achieves a PCE of 13.0% with a high open circuit voltage of 2.52 V.

Efficient Planar Perovskite Solar Cells with Improved Fill Factor via Interface Engineering with Graphene.

Organic-inorganic hybrid lead halide perovskites have been widely investigated in optoelectronics both experimentally and theoretically. The present work incorporates chemically modified graphene into nanocrystal SnO2 as the electron transporting layer (ETL) for highly efficient planar perovskite solar cells. The modification of SnO2 with highly conductive two-dimensional naphthalene diimide-graphene can increase surface hydrophobicity and form van der Waals interaction between the surfactant and the organic-inorganic hybrid lead halide perovskite compounds. As a result, highly efficient perovskite solar cells with power conversion efficiency of 20.2% can be achieved with an improved fill factor of 82%, which could be mainly attributed to the augmented charge extraction and transport.

High Mobility Indium Oxide Electron Transport Layer for an Efficient Charge Extraction and Optimized Nanomorphology in Organic Photovoltaics.

The electron transport layer (ETL) plays an important role in determining the device efficiency of organic solar cells (OSCs). A rational design of an ETL for OSCs targets high charge extraction and induction of an optimized active layer morphology. In this Letter, a high mobility In2O3 synthesized via a solution-processed combustion reaction is successfully used as a universal ETL in an organic photovoltaic device. With the modification of a thin layer of polyethylenimine ethoxylated (PEIE), a device based on crystalline In2O3 outperforms its counterpart, ZnO, in both PBDTTT-EFT-based fullerene and nonfullerene systems. As ZnO is replaced by In2O3, the average efficiency increases from 9.5% to 10.5% for PBDTTT-EFT-PC71BM fullerene-based organic solar cells and also increases from 10.8% to 11.5% for PBDTTT-EFT-IEICO-4F nonfullerene-based organic solar cells, respectively. Morphological studies have unraveled the fact that the crystalline In2O3 ETL with highly aligned nanocrystallites has induced the crystallization of polymer into a preferential molecular packing that favors the charge transport across an active layer. From the photophysical study, it is found that charge extraction in the crystalline In2O3 device is significantly faster than in the ZnO device due to the higher mobility of In2O3 and optimized nanomorphology of the active layer.

Carbon Quantum Dots/TiOx Electron Transport Layer Boosts Efficiency of Planar Heterojunction Perovskite Solar Cells to 19.

In planar n-i-p heterojunction perovskite solar cells, the electron transport layer (ETL) plays important roles in charge extraction and determine the morphology of the perovskite film. Here, we report a solution-processed carbon quantum dots (CQDs)/TiO2 composite that has negligible absorption in the visible spectral range, a very attractive feature for perovskite solar cells. Using this novel CQDs/TiO2 ETL in conjunction with a planar n-i-p heterojunction, we achieved an unprecedented efficiency of ∼19% under standard illumination test conditions. It was found that a CQDs/TiO2 combination increases both the open circuit voltage and short-circuits current density as compared to using TiO2 alone. Various advanced spectroscopic characterizations including ultrafast spectroscopy, ultraviolet photoelectron spectroscopy, and electronic impedance spectroscopy elucidate that the CQDs increases the electronic coupling between the CH3NH3PbI3-xClx and TiO2 ETL interface as well as energy levers that contribute to electron extraction.

Novel porphyrin-preparation, characterization, and applications in solar energy conversion.

Porphyrins have been demonstrated as one of the most efficient sensitizers in dye-sensitized solar cells (DSSC). Herein, we investigated a series of porphyrin sensitizers functionalized with various π-spacers, such as phenyl for LD14, thiophene for LW4, thiophene-phenyl for LW5, and 2,1,3-benzothiadiazole (BTD)-phenyl for LW24. Photo-physical investigation by means of time-resolved fluorescence and nanosecond transient absorption spectroscopy revealed an accelerated inner charge transfer in porphyrins containing the BTD-phenyl π-spacer. Implementation of an auxiliary electron-deficient BTD unit to the porphyrin spacer also results in a broad light-harvesting ability extending up to 840 nm, contributing to an enhanced charge transfer character from the porphyrin ring to the anchoring group. When utilized as a sensitizer in DSSCs, the LW24 device achieved a power conversion efficiency of 9.2%, higher than those based on LD14 or LW5 porphyrins (PCE 9.0% or 8.2%, respectively) but lower than that of the LW4 device (PCE 9.5%). Measurements of transient photovoltage decays demonstrate that the LW24 device features the up-shifted potential band edge of the conduction band of TiO2, but involves serious charge recombination in the dye/TiO2 interface. The findings provide insights into the molecular structure and the charge-transfer characteristics for designing efficient porphyrin sensitizers for DSSC applications.

Working Mechanism for Flexible Perovskite Solar Cells with Simplified Architecture.

In this communication, we report an efficient and flexible perovskite solar cell based on formamidinium lead trihalide (FAPbI3) with simplified configuration. The device achieved a champion efficiency of 12.70%, utilizing direct contact between metallic indium tin oxide (ITO) electrode and perovskite absorber. The underlying working mechanism is proposed subsequently, via a systematic investigation focusing on the heterojunction within this device. A significant charge storage has been observed in the perovskite, which is believed to generate photovoltage and serves as the driving force for charge transferring from the absorber to ITO electrode as well. More importantly, this simplified device structure on flexible substrates suggests its compatibility for scale-up fabrication, which paves the way for commercialization of perovskite photovoltaic technology.

Hole selective NiO contact for efficient perovskite solar cells with carbon electrode.

In this study, we communicate an investigation on efficient CH3NH3PbI3-based solar cells with carbon electrode using mesoporous TiO2 and NiO layers as electron and hole selective contacts. The device possesses an appreciated power conversion efficiency of 14.9% under AM 1.5G illumination. The detailed information can be disclosed with impedance spectroscopy via tuning the interfaces between CH3NH3PbI3 and different charge selective contacts. The results clearly show charge accumulation at the interface of CH3NH3PbI3. The NiO is believed to efficiently accelerate charge extraction to the external circuit. The extracted charge could improve photovoltaic performance by shifting hole Fermi level down, achieving a high device photovoltage. A fast interfacial recombination at the interface of CH3NH3PbI3/electron selective contact layer (mesoporous TiO2), occurring in millisecond domains, is the critical issue for charge carrier recombination loss.

Curcusone D, a novel ubiquitin-proteasome pathway inhibitor via ROS-induced DUB inhibition, is synergistic with bortezomib against multiple myeloma cell growth.

BACKGROUND: Ubiquitin-proteasome pathway (UPP) plays a very important role in the degradation of proteins. Finding novel UPP inhibitors is a promising strategy for treating multiple myeloma (MM). METHODS: Ub-YFP reporter assays were used as cellular UPP models. MM cell growth, apoptosis and overall death were evaluated with the MTS assay, Annexin V/PI dual-staining flow cytometry, poly (ADP-ribose) polymerase (PARP) cleavage, and PI uptake, respectively. The mechanism of UPP inhibition was analyzed by western blotting for ubiquitin, in vitro and cellular proteasomal and deubiquitinases (DUBs) activity assays. Cellular reactive oxygen species (ROS) were measured with H2DCFDA. RESULTS: Curcusone D, identified as a novel UPP inhibitor, causes cell growth inhibition and apoptosis in MM cells. Curcusone D induced the accumulation of poly-ubiquitin-conjugated proteins but could not inhibit proteasomal activity in vitro or in cells. Interestingly, the mono-ubiquitin level and the total cellular DUB activity were significantly downregulated following curcusone D treatment. Furthermore, curcusone D could induce ROS, which were closely correlated with DUB inhibition that could be nearly completely reversed by NAC. Finally, curcusone D and the proteasomal inhibitor bortezomib showed a strong synergistic effect against MM cells. CONCLUSIONS: Curcusone D is novel UPP inhibitor that acts via the ROS-induced inhibition of DUBs to produce strong growth inhibition and apoptosis of MM cells and synergize with bortezomib. GENERAL SIGNIFICANCE: The anti-MM molecular mechanism study of curcusone D will promote combination therapies with different UPP inhibitors against MM and further support the concept of oxidative stress regulating the activity of DUBs.

Meroterpenoids and a naphthoquinone from Arnebia euchroma and their cytotoxic activity.

Four new meroterpenoids, arnebinols A-D (1-4), and one new prenylated naphthoquinone, 5,8-O-dimethyl-11-deoxyalkannin (5), together with seven known meroterpenoids (6-12) were isolated from the roots of Arnebia euchroma. The structures of the isolated compounds were elucidated unambiguously by spectroscopic data analysis, as well as X-ray-single crystal diffraction analysis. Arnebinol A (1) and B (2) are rare meroterpenoids possessing a 6/10/5 tricyclic ring system. Compounds 1-12 were evaluated for their cytotoxicities against MG-63 and SNU387 human cancer cell lines. Compound 5 exhibited the most potent activity with IC50 values of 2.69 µM and 6.08 µM, respectively.