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Cs2AgBiBr6 double perovskites are considered potential alternatives to lead-based perovskites for solar cell applications owing to their advantages of stability and non-toxicity. However, the disordered arrangement of Ag/Bi octahedra leads to the formation of self-trapped excitons (STEs) and hinders carrier transport, which is a severe problem in planar solar cells due to inferior charge extraction to mesoporous solar cells. Herein, we employ ethoxylated polyethylenimine (PEIE) to regulate the growth of Cs2AgBiBr6 films by sandwiching it between an SnO2 electron transport layer and a perovskite layer. On the one hand, the introduction of PEIE delays the growth of Cs2AgBiBr6 and improves the ordering extent of the Ag/Bi octahedra. This inhibits the formation of STEs and facilitates carrier transport, which profoundly boosts the short-circuit current density. On the other hand, PEIE modulates the energy level of the SnO2 electron transport layer to match that of Cs2AgBiBr6, which reduces the open-circuit voltage loss. Consequently, the power conversion efficiency (PCE) of the planar solar cell increases by 250% after PEIE modification from 0.59% to 1.52%. In addition, the PEIE-decorated device maintains over 90% of its initial PCE for 30 days under ambient conditions, demonstrating good environmental stability. [ABSTRACT FROM AUTHOR]

The integrated dual-channel pathway is regarded as an ideal process for photocatalytic H2O2 production. However, it is a key scientific challenge to rationally design photocatalysts for achieving H2O2 production through such a dual-channel pathway. Here, we designed surface oxygen vacancy-modified BiOIO3 (BIO-OVs-x) with spatially separated redox reaction centers by constructing a facet heterojunction for directly utilizing O2 and H2O to photosynthesize H2O2. Under white light irradiation, optimal BIO-OVs-2 exhibited the highest H2O2 production rate of 215.5 μmol g–1 h–1, which was 3 times more than that of BiOIO3, as well as an apparent quantum yield of 5.76% at 350 nm. Photoelectrochemical experiments confirmed that the introduction of oxygen vacancies boosted the efficiency of charge separation and transfer and adjusted the band structure. Control experiments and theoretical studies elucidated photocatalytic reaction active sites and the charge transport mechanism of BIO-OV catalysts. More importantly, the introduction of oxygen vacancies in BiOIO3 reduced the free energy for OH* of the water oxidation reaction and promoted the occurrence of the water oxidation reaction. This work provides a valuable basis for the fine design of a high-performance photocatalyst and for understanding the mechanism of hydrogen peroxide production. [ABSTRACT FROM AUTHOR]

Due to the low tolerance factor, the black-phase CsPbI3 could easily transform into the photovoltaic-inactive yellow phase under the pressure of moisture, restricting the performance and stability of corresponding solar cells. Here, Ca(CF3SO3)2 is introduced into CsPbI3 to solve this problem. The Ca2+ cations could interact with I− ions to inhibit ion migration and prevent the collapse of the perovskite structure, while the CF3SO3− anions anchoring on the crystal surface could provide hydrophobicity. Ca(CF3SO3)2 introduction, thus, increases the intrinsic and extrinsic stability of black-phase CsPbI3 simultaneously. The interaction between Ca(CF3SO3)2 and perovskite precursors retards the crystallization process and facilitates the growth of high-quality films with reduced non-radiative recombination. Moreover, the CF3SO3− anions on the surface induce p-type doping and modify the energy level alignment with the hole transport layer. Benefiting from the Ca(CF3SO3)2 introduction, the CsPbI3 all-inorganic perovskite solar cells exhibit improved power conversion efficiency (PCE) from 14.76% to 16.50%. In addition, the unencapsulated device with Ca(CF3SO3)2 retains 81% of its original PCE after storage in air for 500 h, outperforming that of the control device (65%). [ABSTRACT FROM AUTHOR]

Many emerging markets rely on land financing, whereby land grants are used to raise funds for the government. In the short term, land financing eases the government's fiscal deficit and boosts regional economic development. However, the long-term implications of such behaviour have not been adequately discussed. This study focuses on the relationship between local government land finance dependence (LGLFD) and urban innovation quality (UIQ). We find that LGLFD significantly inhibits the improvement of UIQ, and this inhibition occurs through three main channels: changing government spending preferences, reducing financial efficiency, and deteriorating the institutional environment. Our empirical study analyses 3662 samples from 264 Chinese cities from 2003 to 2016, confirming our research hypothesis. Further research finds that there is significant heterogeneity in the effect of LGLFD on UIQ. Based on these conclusions, some policy implications are proposed. [ABSTRACT FROM AUTHOR]

Acute lung injury (ALI) is the leading cause of death in patients with sepsis syndrome and without effective protective or therapeutic treatments. Acacetin, a natural dietary flavonoid, reportedly exerts several biological effects, such as anti-tumor, anti-inflammatory, and anti-oxidative effects. However, acacetin's effect and underlying mechanism on sepsis-induced ALI remain unclear. Here, the mouse model was established to explore the impact of acacetin on sepsis-induced ALI. Acacetin significantly increased ALI murine survival and attenuated lung injury in histological examinations. Additionally, acacetin down-regulated myeloperoxidase activity, protein concentration, and number of neutrophils and macrophages in bronchoalveolar lavage fluid. Subsequently, inflammatory cytokines, including TNF-α, IL-1β, and IL-6, were examined. Results showed that acacetin dramatically suppressed the production of TNF-α, IL-1β, and IL-6. These above results indicated that acacetin attenuated sepsis-induced ALI by inhibiting the inflammatory response. Moreover, acacetin inhibited the expression of markers for M1-type (iNOS, CD86) macrophages and promoted the expression of markers for M2-type (CD206, Arg1) macrophages by western blot. In addition, acacetin down-regulated the expression TRAF6, NF-κB, and Cyclooxygenase-2 (COX2) by western blot. The high concentration of acacetin had a better effect than the low concentration. Besides, over-expression of TRAF6 up-regulated the expression of COX2, CD86, and iNOS, and the ratio of p-NF-κB to NF-κB increased the mRNA levels of TNF-α, IL-1β, and IL-6, down-regulated the expression of CD206 and Arg1. The effects of TRAF6 were the opposite of acacetin. And TRAF6 could offset the impact of acacetin. This study demonstrated that acacetin could prevent sepsis-induced ALI by facilitating M2 macrophage polarization via TRAF6/NF-κB/COX2 axis. [ABSTRACT FROM AUTHOR]

Photo-driven fixation of nitrogen (N2) to ammonia (NH3) is a kinetically complex multielectron reaction process. The key to photocatalytic N2 fixation lies in designing photocatalysts with high photoinduced carrier separation efficiency and sufficient active sites for adsorbing and activating N2 molecules. Herein, we constructed a Schottky junction photocatalyst made of mesoporous hollow carbon nitride (C3N4) spheres decorated with partially reduced Ti3C2 quantum dots (r-Ti3C2 QDs) on the surface for efficient N2 photofixation. The Schottky junction is formed at the interface between C3N4 spheres and r-Ti3C2 QDs, which enables the spatial separation of photogenerated electrons and holes, resulting in suppression of charge carrier recombination. Notably, the surface of r-Ti3C2 QDs is rich in Ti3+ sites and oxygen vacancy (OV) defect state sites. Such double defect sites of Ti3+ and OVs facilitate the capture and activation of N2 molecules, leading to efficient reduction of preactivated N2 molecules to NH3 by the trapped electrons transferred from the photoexcited C3N4 hollow spheres. The resultant photocatalysts exhibited a remarkably enhanced N2 photofixation activity with an optimal NH3 production rate of 328.9 μmol h−1 gcat−1. This work not only provides an alternative strategy to engineer defect sites and regulate the charge transfer pathway on photocatalysts, but also sheds new light on developing efficient MXene-based photocatalysts for broadening their photocatalytic applications. [ABSTRACT FROM AUTHOR]