Ru-P pair sites boost charge transport in hematite photoanodes for exceeding 1% efficient solar water splitting.

Fast transport of charge carriers in semiconductor photoelectrodes are a major determinant of the solar-to-hydrogen efficiency for photoelectrochemical (PEC) water slitting. While doping metal ions as single atoms/clusters in photoelectrodes has been popularly used to regulate their charge transport, PEC performances are often low due to the limited charge mobility and severe charge recombination. Here, we disperse Ru and P diatomic sites onto hematite (DASs Ru-P:Fe2O3) to construct an efficient photoelectrode inspired by the concept of correlated single-atom engineering. The resultant photoanode shows superior photocurrent densities of 4.55 and 6.5 mA cm-2 at 1.23 and 1.50 VRHE, a low-onset potential of 0.58 VRHE, and a high applied bias photon-to-current conversion efficiency of 1.00% under one sun illumination, which are much better than the pristine Fe2O3. A detailed dynamic analysis reveals that a remarkable synergetic ineraction of the reduced recombination by a low Ru doping concentration with substitution of Fe site as well as the construction of Ru-P bonds in the material increases the carrier separation and fast charge transportation dynamics. A systematic simulation study further proves the superiority of the Ru-P bonds compared to the Ru-O bonds, which allows more long-lived carriers to participate in the water oxidation reaction. This work offers an effective strategy for enhancing charge carrier transportation dynamics by constructing pair sites into semiconductors, which may be extended to other photoelectrodes for solar water splitting.

Elucidating the photodissociation fingerprint and quantifying the determination of organic hydroperoxides in gas-phase autoxidation.

Hydroperoxides are formed in the atmospheric oxidation of volatile organic compounds, in the combustion autoxidation of fuel, in the cold environment of the interstellar medium, and also in some catalytic reactions. They play crucial roles in the formation and aging of secondary organic aerosols and in fuel autoignition. However, the concentration of organic hydroperoxides is seldom measured, and typical estimates have large uncertainties. In this work, we developed a mild and environmental-friendly method for the synthesis of alkyl hydroperoxides (ROOH) with various structures, and we systematically measured the absolute photoionization cross-sections (PICSs) of the ROOHs using synchrotron vacuum ultraviolet-photoionization mass spectrometry (SVUV-PIMS). A chemical titration method was combined with an SVUV-PIMS measurement to obtain the PICS of 4-hydroperoxy-2-pentanone, a typical molecule for combustion and atmospheric autoxidation ketohydroperoxides (KHPs). We found that organic hydroperoxide cations are largely dissociated by loss of OOH. This fingerprint was used for the identification and accurate quantification of the organic peroxides, and it can therefore be used to improve models for autoxidation chemistry. The synthesis method and photoionization dataset for organic hydroperoxides are useful for studying the chemistry of hydroperoxides and the reaction kinetics of the hydroperoxy radicals and for developing and evaluating kinetic models for the atmospheric autoxidation and combustion autoxidation of the organic compounds.

Designing Atomic Interface in Sb2 S3 /CdS Heterojunction for Efficient Solar Water Splitting.

In the emerging Sb2 S3 -based solar energy conversion devices, a CdS buffer layer prepared by chemical bath deposition is commonly used to improve the separation of photogenerated electron-hole pairs. However, the cation diffusion at the Sb2 S3 /CdS interface induces detrimental defects but is often overlooked. Designing a stable interface in the Sb2 S3 /CdS heterojunction is essential to achieve high solar energy conversion efficiency. As a proof of concept, this study reports that the modification of the Sb2 S3 /CdS heterojunction with an ultrathin Al2 O3 interlayer effectively suppresses the interfacial defects by preventing the diffusion of Cd2+ cations into the Sb2 S3 layer. As a result, a water-splitting photocathode based on Ag:Sb2 S3 /Al2 O3 /CdS heterojunction achieves a significantly improved half-cell solar-to-hydrogen efficiency of 2.78% in a neutral electrolyte, as compared to 1.66% for the control Ag:Sb2 S3 /CdS device. This work demonstrates the importance of designing atomic interfaces and may provide a guideline for the fabrication of high-performance stibnite-type semiconductor-based solar energy conversion devices.

A Enhanced Fluorescent Probe for Simultaneous Detection and Discrimination of Hydrogen Bisulfite Anions and Glutathione.

Bisulfite (HSO3-) and biological thiols molecules, such as glutathione (GSH), cysteine (Cys), and homocysteine (Hcy), play important roles in organisms. Developing a fluorescent probe that can simultaneously detect and distinguish HSO3- and biological thiols is of great significance. In this study, ethyl(2E,4Z)-5-chloro-2-cyano-5-(7-(diethylamino)-2-oxo-2 H-chromen-3-yl)penta-2,4-dienoate (CCO) as a novel enhanced fluorescence probe was synthesized by integrating coumarin derivatives and ethyl cyanoacetate, which can simultaneous detection and discrimination of hydrogen bisulfite anions and glutathione. The sensing mechanism was elucidated through spectral analysis and some control experiments. In weakly alkaline environments, the probe not only has good selectivity for HSO3- and GSH, but also has a lower detection limits of 0.0179 µM and 0.2034 µM. The probe exhibited fuorescent turn-on for distinguishing with 296 and 28 fold the fluorescent intensity increase at 486 and 505 nm, respectively, through diferent excitation wavelengths. This provides a new method for simultaneous detection and discrimination of HSO3- and biological thiol cell levels and further applications.

Ferroptosis contributing to cardiomyocyte injury induced by silica nanoparticles via miR-125b-2-3p/HO-1 signaling.

BACKGROUND: Amorphous silica nanoparticles (SiNPs) have been gradually proven to threaten cardiac health, but pathogenesis has not been fully elucidated. Ferroptosis is a newly defined form of programmed cell death that is implicated in myocardial diseases. Nevertheless, its role in the adverse cardiac effects of SiNPs has not been described. RESULTS: We first reported the induction of cardiomyocyte ferroptosis by SiNPs in both in vivo and in vitro. The sub-chronic exposure to SiNPs through intratracheal instillation aroused myocardial injury, characterized by significant inflammatory infiltration and collagen hyperplasia, accompanied by elevated CK-MB and cTnT activities in serum. Meanwhile, the activation of myocardial ferroptosis by SiNPs was certified by the extensive iron overload, declined FTH1 and FTL, and lipid peroxidation. The correlation analysis among detected indexes hinted ferroptosis was responsible for the SiNPs-aroused myocardial injury. Further, in vitro tests, SiNPs triggered iron overload and lipid peroxidation in cardiomyocytes. Concomitantly, altered expressions of TfR, DMT1, FTH1, and FTL indicated dysregulated iron metabolism of cardiomyocytes upon SiNP stimuli. Also, shrinking mitochondria with ridge fracture and ruptured outer membrane were noticed. To note, the ferroptosis inhibitor Ferrostatin-1 could effectively alleviate SiNPs-induced iron overload, lipid peroxidation, and myocardial cytotoxicity. More importantly, the mechanistic investigations revealed miR-125b-2-3p-targeted HO-1 as a key player in the induction of ferroptosis by SiNPs, probably through regulating the intracellular iron metabolism to mediate iron overload and ensuing lipid peroxidation. CONCLUSIONS: Our findings firstly underscored the fact that ferroptosis mediated by miR-125b-2-3p/HO-1 signaling was a contributor to SiNPs-induced myocardial injury, which could be of importance to elucidate the toxicity and provide new insights into the future safety applications of SiNPs-related nano products.

Epithelium-derived exosomes promote silica nanoparticles-induced pulmonary fibroblast activation and collagen deposition via modulating fibrotic signaling pathways and their epigenetic regulations.

BACKGROUND: In the context of increasing exposure to silica nanoparticles (SiNPs) and ensuing respiratory health risks, emerging evidence has suggested that SiNPs can cause a series of pathological lung injuries, including fibrotic lesions. However, the underlying mediators in the lung fibrogenesis caused by SiNPs have not yet been elucidated. RESULTS: The in vivo investigation verified that long-term inhalation exposure to SiNPs induced fibroblast activation and collagen deposition in the rat lungs. In vitro, the uptake of exosomes derived from SiNPs-stimulated lung epithelial cells (BEAS-2B) by fibroblasts (MRC-5) enhanced its proliferation, adhesion, and activation. In particular, the mechanistic investigation revealed SiNPs stimulated an increase of epithelium-secreted exosomal miR-494-3p and thereby disrupted the TGF-ß/BMPR2/Smad pathway in fibroblasts via targeting bone morphogenetic protein receptor 2 (BMPR2), ultimately resulting in fibroblast activation and collagen deposition. Conversely, the inhibitor of exosomes, GW4869, can abolish the induction of upregulated miR-494-3p and fibroblast activation in MRC-5 cells by the SiNPs-treated supernatants of BEAS-2B. Besides, inhibiting miR-494-3p or overexpression of BMPR2 could ameliorate fibroblast activation by interfering with the TGF-ß/BMPR2/Smad pathway. CONCLUSIONS: Our data suggested pulmonary epithelium-derived exosomes serve an essential role in fibroblast activation and collagen deposition in the lungs upon SiNPs stimuli, in particular, attributing to exosomal miR-494-3p targeting BMPR2 to modulate TGF-ß/BMPR2/Smad pathway. Hence, strategies targeting exosomes could be a new avenue in developing therapeutics against lung injury elicited by SiNPs.

Electrosynthesis of an Improbable Directly Bonded Phosphorene-Fullerene Heterodimensional Hybrid toward Boosted Photocatalytic Hydrogen Evolution.

Phosphorene and fullerene are representative two-dimensional (2D) and zero-dimensional (0D) nanomaterials respectively, constructing their heterodimensional hybrid not only complements their physiochemical properties but also extends their applications via synergistic interactions. This is however challenging because of their diversities in dimension and chemical reactivity, and theoretical studies predicted that it is improbable to directly bond C60 onto the surface of phosphorene due to their strong repulsion. Here, we develop a facile electrosynthesis method to synthesize the first phosphorene-fullerene hybrid featuring fullerene surface bonding via P-C bonds. Few-layer black phosphorus nanosheets (BPNSs) obtained from electrochemical exfoliation react with C602- dianion prepared by electroreduction of C60, fulfilling formation of the "improbable" phosphorene-fullerene hybrid (BPNS-s-C60). Theoretical results reveal that the energy barrier for formation of [BPNS-s-C60]2- intermediate is significantly decreased by 1.88 eV, followed by an oxidization reaction to generate neutral BPNS-s-C60 hybrid. Surface bonding of C60 molecules not only improves significantly the ambient stability of BPNSs, but also boosts dramatically the visible light and near-infrared (NIR) photocatalytic hydrogen evolution rates, reaching 1466 and 1039 µmol h-1 g-1 respectively, which are both the highest values among all reported BP-based metal-free photocatalysts.

Correlation analysis between shear-wave elastography and pathological profiles in breast cancer.

PURPOSE: To explore the correlation between shear-wave elastography (SWE) parameters and pathological profiles of invasive breast cancer. METHODS: A total of 197 invasive breast cancers undergoing preoperative SWE and primary surgical treatment were included. Maximum elastic modulus (Emax), mean elastic modulus (Emean), and elastic modulus standard deviation (Esd) were calculated by SWE. Pathological profile was gold standard according to postoperative pathology. The relationship between SWE parameters and pathological factors were analyzed using univariate and multivariate analysis. RESULTS: In univariate analysis, large cancers showed significantly higher Emax, Emean and Esd (all P < 0.001). Emax and Esd in the group of histological grade III were higher than those in the group of grade I (both P < 0.05). Invasive lobular carcinomas (ILC) showed higher Emean than invasive ductal carcinoma (IDC) (P < 0.001). Lymphovascular invasion (LVI) group showed higher Emax values than negative group (P < 0.05). Emax, Emean and Esd of the Ki-67 positive group presented higher values than negative group (all P < 0.05). Androgen receptor (AR) positive lesions had lower Esd than AR negative lesions (P < 0.05). In multivariate analysis, invasive size independently influenced Emax (P < 0.001). Invasive size and pathological type both independently influenced Emean (both P < 0.001). Invasive size and AR status were both independently influenced Esd (both P < 0.05). CONCLUSION: SWE parameters correlated with pathological profiles of invasive breast cancer.In particular, AR positive group showed significantly low Esd than negative group.

Silica Nanoparticles Trigger Chaperone HSPB8-Assisted Selective Autophagy via TFEB Activation in Hepatocytes.

Silica nanoparticles (SiNPs) are one of the most common inorganic nanomaterials. Autophagy is the predominant biological response to nanoparticles and transcription factor EB (TFEB) is a master regulator of the autophagy-lysosome pathway. Previous studies show that SiNPs induce autophagosome accumulation, yet the precise underlying mechanisms remain uncertain. The present study investigates the role of TFEB during SiNP-induced autophagy. SiNP-induced TFEB nuclear translocation is verified using immunofluorescence and western blot assay. The regulation of TFEB is proved to be via EIF2AK3 pathway. A TFEB knockout (KO) cell line is constructed to validate the TFEB involvement in SiNP-induced autophagy. The transcriptomes of wild-type and TFEB KO cells are compared using RNA-sequencing to identify genes of the TFEB-mediated autophagy and lysosome pathways affected by SiNPs. Based on these data and the Human Autophagy Database, four candidate autophagic genes are identified, including HSPB8, ATG4D, CTSB and CTSD. Specifically, that the chaperone HSPB8 is upregulated through SiNP-mediated TFEB activation and forms a chaperone-assisted selective autophagy (CASA) complex with BAG3 and HSC70, triggering HSPB8-assisted selective autophagy, is found. Thus, this study characterizes a novel mechanism underlying SiNP-induced autophagy that helps pave the way for further research on the toxicity and risk assessment of SiNPs.

Expansion of carbon source utilization range of Shewanella oneidensis for efficient azo dye wastewater treatment through co-culture with Lactobacillus plantarum.

Shewanella oneidensis has demonstrated excellent potential for azo dye decolorization and degradation. However, in anaerobic environments, S. oneidensis has a narrow carbon source spectrum, which requires additional electron donors, such as sodium lactate. This increases the practical application costs for wastewater treatment. Here, we aimed to expand the carbon source utilization range of S. oneidensis FJAT-2478 by co-culturing it with Lactobacillus plantarum FJAT-7926, leveraging their commensalism relationship to develop a metabolic chain. Results showed that a 1:2 initial ratio of L. plantarum FJAT-7926 to S. oneidensis FJAT-2478 achieved a 97.16% decolorization rate of methyl orange when glucose served as the sole carbon source. This co-culture system achieved a decolorization rate comparable to that obtained using sodium lactate as an electron donor and was significantly higher than that achieved by L. plantarum FJAT-7926 (7.88%) or S. oneidensis FJAT-2478 (6.89%) alone. After undergoing five cycles, the co-culture system continued to exhibit effective decolorization. It was demonstrated that the co-culture system could use common and inexpensive carbon sources, such as starch, molasses, sucrose, and maltose, to decolorize azo dyes. For instance, 100 mg/L methyl orange could be degraded by over 98.05% within 24 h. The results indicated that the degradation rates of methyl orange were higher when L. plantarum was inoculated first, followed by a subsequent inoculation of S. oneidensis after 2 h. The co-culturing of L. plantarum FJAT-7926 and S. oneidensis FJAT-2478 proved to be an effective strategy in treating azo dye wastewater, expanding the potential practical applications of S. oneidensis.

IL-22 promotes occludin expression by activating autophagy and treats ulcerative colitis.

IL-22 serves a protective function in the intestinal barrier. These protective properties of IL-22 may offer a potential treatment for ulcerative colitis (UC). However, the exact mechanisms of action remain unclear. Autophagy plays an important protective role in stabilizing the intestinal barrier. We aimed to explore the role of autophagy in the IL-22-mediated-protective effects in UC. Dextran sulfate sodium (DSS) was administrated via drinking water over 7 days to induce acute UC in BALB/c mice. Treatments with IL-22 (0.25 µg/10 g bodyweight) were started by intraperitoneal injection on days 1, 3, and 5. Weight, disease activity index, histological score, and myeloperoxidase (MPO) activity were used to evaluate the severity of colitis. The expressions of occludin and autophagy-related proteins LC3BII/I were measured by western blot analysis. The lipopolysaccharide-induced HT-29 cell model was used to explore the mechanism. In vivo, IL-22 significantly alleviated DSS-induced clinical manifestations, reduced histological injury, and inhibited MPO activity. IL-22 upregulated the expression of occludin and the LC3B II/I ratio in the colon. In vitro, IL-22 significantly lowered TNF-α levels and enhanced the expression of occludin and the LC3B II/I ratio. Importantly, inhibiting autophagy in vitro by 3-Methyladenine (3-MA) attenuated the occludin protective effects of IL-22. In summary, our findings demonstrate that IL-22 ameliorates DSS-induced ulcerative colitis, which may be attributable to activating autophagy and then promoting occludin expression.

Pre- and postnatal particulate matter exposure and blood pressure in children and adolescents: A systematic review and meta-analysis.

BACKGROUND: Early life is a susceptible period of air pollution-related adverse health effects. Hypertension in children might be life-threatening without prevention or treatment. Nevertheless, the causative association between environmental factors and childhood hypertension was limited. In the light of particulate matter (PM) as an environmental risk factor for cardiovascular diseases, this study investigated the association of pre- and postnatal PM exposure with blood pressure (BP) and hypertension among children and adolescents. METHOD: Four electronic databases were searched for related epidemiological studies published up to September 13, 2022. Stata 14.0 was applied to examine the heterogeneity among the studies and evaluate the combined effect sizes per 10 µg/m3 increase of PM by selecting the corresponding models. Besides, subgroup analysis, sensitivity analysis, and publication bias test were also conducted. RESULTS: Prenatal PM2.5 exposure was correlated with increased diastolic blood pressure (DBP) in offspring [1.14 mmHg (95% CI: 0.12, 2.17)]. For short-term postnatal exposure effects, PM2.5 (7-day average) was significantly associated with systolic blood pressure (SBP) [0.20 mmHg (95% CI: 0.16, 0.23)] and DBP [0.49 mmHg (95% CI: 0.45, 0.53)]; and also, PM10 (7-day average) was significantly associated with SBP [0.14 mmHg (95% CI: 0.12, 0.16)]. For long-term postnatal exposure effects, positive associations were manifested in SBP with PM2.5 [ß = 0.44, 95% CI: 0.40, 0.48] and PM10 [ß = 0.35, 95% CI: 0.19, 0.51]; DBP with PM1 [ß = 0.45, 95% CI: 0.42, 0.49], PM2.5 [ß = 0.31, 95% CI: 0.27, 0.35] and PM10 [ß = 0.32, 95% CI: 0.19, 0.45]; and hypertension with PM1 [OR = 1.43, 95% CI: 1.40, 1.46], PM2.5 [OR = 1.65, 95% CI: 1.29, 2.11] and PM10 [OR = 1.26, 95% CI: 1.09, 1.45]. CONCLUSION: Both prenatal and postnatal exposure to PM can increase BP, contributing to a higher prevalence of hypertension in children and adolescents.

Corticosteroids for preventing postherpetic neuralgia.

BACKGROUND: Postherpetic neuralgia (PHN) is a common, serious, painful complication of herpes zoster. Corticosteroids have anti-inflammatory properties, and might be beneficial. This is an update of a review first published in 2008, and previously updated in 2013. OBJECTIVES: To assess the effects (benefits and harms) of corticosteroids in preventing postherpetic neuralgia. SEARCH METHODS: We updated the searches for randomised controlled trials (RCTs) of corticosteroids for preventing postherpetic neuralgia in the Cochrane Neuromuscular Specialised Register, CENTRAL, MEDLINE, Embase, two other databases, and two trials registers (June 2022). We also reviewed the bibliographies of identified trials, contacted authors, and approached pharmaceutical companies to identify additional published or unpublished data. SELECTION CRITERIA: We included all RCTs involving corticosteroids given by oral, intramuscular, or intravenous routes for people of all ages, with herpes zoster of all degrees of severity within seven days after onset, compared with no treatment or placebo, but not with other treatments. DATA COLLECTION AND ANALYSIS: Two review authors independently identified potential articles, extracted data, assessed the risk of bias of each trial, and the certainty of the evidence. Disagreement was resolved by discussion among the co-authors. We followed standard Cochrane methodology. MAIN RESULTS: We identified five trials with a total of 787 participants that met our inclusion criteria. No new studies were identified for this update. All were randomised, double-blind, placebo-controlled parallel-group studies. The evidence is very uncertain about the effects of corticosteroids given orally during an acute herpes zoster infection in preventing postherpetic neuralgia six months after the onset of herpes (risk ratio (RR) 0.95, 95% confidence interval (CI) 0.45 to 1.99; 2 trials, 114 participants; very low-certainty evidence (downgraded for serious risk of bias and very serious imprecision)). The three other trials that fulfilled our inclusion criteria were not included in the meta-analysis because they did not provide separate information on the number of participants with PHN at six months. Adverse events during or within two weeks after stopping treatment were reported in all five included trials. There were no observed differences in serious (RR 1.65, 95% CI 0.51 to 5.29; 5 trials, 755 participants; very low-certainty evidence (downgraded for serious risk of bias and very serious imprecision)), or non-serious adverse events (RR 1.30, 95% CI 0.90 to 1.87; 5 trials, 755 participants; low-certainty evidence (downgraded for serious risk of bias and serious imprecision)) between the corticosteroid and placebo groups. One of these trials was at high risk of bias because of incomplete outcome data, two were at unclear risk of bias, and the other was at low risk of bias. The review was first published in 2008; no new RCTs were identified for inclusion in subsequent updates in 2010, 2013, and 2023. AUTHORS' CONCLUSIONS: Based on the current available evidence, we are uncertain about the effects of corticosteroids given orally during an acute herpes zoster infection on preventing postherpetic neuralgia. Corticosteroids given orally or intramuscularly may result in little to no difference in the risk of adverse events in people with acute herpes zoster. Some researchers have recommended using corticosteroids to relieve the zoster-associated pain in the acute phase of the disease. If further research is designed to evaluate the efficacy of corticosteroids for herpes zoster, long-term follow-up should be included to observe their effect on the transition from acute pain to postherpetic neuralgia. Future trials should include measurements of function and quality of life, as well as updated measures of pain.

PSMA1-mediated ultrasmall gold nanoparticles facilitate tumor targeting and MR/CT/NIRF multimodal detection of early-stage prostate cancer.

Prostate-specific membrane antigen (PSMA) is a prominent biomarker for prostate cancer (PCa) diagnosis. Safe contrast agents able to render the expression and distribution of PSMA would facilitate early accurate screening and prognostic prediction of PCa. However, current Gd-containing nanoparticles are often limited by nonspecific redistribution in mononuclear phagocyte system (MPS) and inadequate perfusion to target sites. Besides, intrinsic defects of magnetic resonance (MR) equipment also hamper their use for precisely depicting PSMA details. Herein, we devised a novel noninvasive MR/CT/NIRF multimodal contrast agent (AGGP) coordinated to a high-affinity PSMA ligand (PSMA1) to specifically detect and quantify PSMA expression in PCa lesions, which exhibited formidable tripe-modal signal augments, preferential PSMA targeting, effective MPS escaping and profitable renal-clearable behavior in living mice. Biocompatibility and histopathological studies substantiated high security of AGGP in vivo, opening the door to future opportunities for improving early-stage PCa detection and clinical implementation of more effective multifunctional nanotherapeutics.

Direct Detection of FeVI Water Oxidation Intermediates in an Aqueous Solution.

In situ detection of highly-oxidized metal intermediates is the key to identifying the active center of an oxygen evolution reaction (OER) catalyst, but it remains challenging for NiFe-based catalysts in an aqueous solution under working conditions. Here, by utilizing the dynamic stability of the FeVI O4 2- intermediates in a self-healing water oxidation cycle of NiFe-based catalyst, the highly-oxidized FeVI intermediates leached into the electrolyte are directly detected by simple spectroelectrochemistry. Our results provide direct evidence that Fe is the active center in NiFe-based OER catalysts. Furthermore, it is revealed that the incorporation of Co into NiFe-based catalyst facilitates the formation of FeVI active species, thus enhancing the OER activity of NiCoFe-based catalyst. The insights into the mechanisms for the sustainable generation of FeVI active species in these NiFe-based catalysts lay the foundation for the design of more efficient and stable OER catalysts.

Enhanced Spatial Charge Separation in a Niobium and Tantalum Nitride Core-Shell Photoanode: In Situ Interface Bonding for Efficient Solar Water Splitting.

Tantalum nitride (Ta3 N5 ) has emerged as a promising photoanode material for photoelectrochemical (PEC) water splitting. However, the inefficient electron-hole separation remains a bottleneck that impedes its solar-to-hydrogen conversion efficiency. Herein, we demonstrate that a core-shell nanoarray photoanode of NbNx -nanorod@Ta3 N5 ultrathin layer enhances light harvesting and forms a spatial charge-transfer channel, which leads to the efficient generation and extraction of charge carriers. Consequently, an impressive photocurrent density of 7 mA cm-2 at 1.23 VRHE is obtained with an ultrathin Ta3 N5 shell thickness of less than 30 nm, accompanied by excellent stability and a low onset potential (0.46 VRHE ). Mechanistic studies reveal the enhanced performance is attributed to the high-conductivity NbNx core, high-crystalline Ta3 N5 mono-grain shell, and the intimate Ta-N-Nb interface bonds, which accelerate the charge-separation capability of the core-shell photoanode. This study demonstrates the key roles of nanostructure design in improving the efficiency of PEC devices.

Criteria for Efficient Photocatalytic Water Splitting Revealed by Studying Carrier Dynamics in a Model Al-doped SrTiO3 Photocatalyst.

Overall water splitting (OWS) using semiconductor photocatalysts is a promising method for solar fuel production. Achieving a high quantum efficiency is one of the most important prerequisites for photocatalysts to realize high solar-to-fuel efficiency. In a recent study (Nature 2020, 58, 411-414), a quantum efficiency of almost 100 % has been achieved in an aluminum-doped strontium titanate (SrTiO3 : Al) photocatalyst. Herein, using the SrTiO3 : Al as a model photocatalyst, we reveal the criteria for efficient photocatalytic water splitting by investigating the carrier dynamics through a comprehensive photoluminescence study. It is found that the Al doping suppresses the generation of Ti3+ recombination centers in SrTiO3 , the surface band bending facilitates charge separation, and the in situ photo-deposited Rh/Cr2 O3 and CoOOH co-catalysts render efficient charge extraction. By suppressing photocarrier recombination and establishing a facile charge separation and extraction mechanism, high quantum efficiency can be achieved even on photocatalysts with a very short (sub-ns) intrinsic photocarrier lifetime, challenging the belief that a long carrier lifetime is a fundamental requirement. Our findings could provide guidance on the design of OWS photocatalysts toward more efficient solar-to-fuel conversion.

Isolated Electron-Rich Ruthenium Atoms in Intermetallic Compounds for Boosting Electrochemical Nitric Oxide Reduction to Ammonia.

The direct electrochemical nitric oxide reduction reaction (NORR) is an attractive technique for converting NO into NH3 with low power consumption under ambient conditions. Optimizing the electronic structure of the active sites can greatly improve the performance of electrocatalysts. Herein, we prepare body-centered cubic RuGa intermetallic compounds (i.e., bcc RuGa IMCs) via a substrate-anchored thermal annealing method. The electrocatalyst exhibits a remarkable NH4 + yield rate of 320.6 µmol h-1 mg-1 Ru with the corresponding Faradaic efficiency of 72.3 % at very low potential of -0.2 V vs. reversible hydrogen electrode (RHE) in neutral media. Theoretical calculations reveal that the electron-rich Ru atoms in bcc RuGa IMCs facilitate the adsorption and activation of *HNO intermediate. Hence, the energy barrier of the potential-determining step in NORR could be greatly reduced.

Numerical investigation of field-effect control on hybrid electrokinetics for continuous and position-tunable nanoparticle concentration in microfluidics.

We introduce herein an effective way for continuous delivery and position-switchable trapping of nanoparticles via field-effect control on hybrid electrokinetics (HEK). Flow field-effect transistor exploiting HEK delicately combines horizontal linear electroosmosis and transversal nonlinear electroosmosis of a shiftable flow stagnation line (FSL) on gate terminals under DC-biased AC forcing. The microfluidic nanoparticle concentrator proposed herein makes use of a simple device geometry, in which an individual or a series of planar metal strips serving as gate electrode (GE) are subjected to a hybrid gate voltage signal and arranged in parallel between a pair of 3D driving electrodes. On the application of a DC-biased AC electric field across channel length direction, all the GE are electrochemically polarized, and the action of imposed hybrid electric field on the multiple-frequency bipolar counterions within the composite-induced double layer generates two counter-rotating induced-charge electroosmotic (ICEO) micro-vortices on top of each GE. Symmetry breaking in ICEO flow profile occurs once the gate voltage deviates from natural floating potential of corresponding GE. The gate voltage offset not only results in an additional pump motion of working fluid for enhanced electroosmotic transport but also directly changes the location of FSL where nanoparticles are preferentially collected by field-effect HEK. Our results of field-effect control on HEK are supposed to guide an elaborate design of flexible electrokinetic frameworks embedding coplanar metal strips for a high degree of freedom analyte manipulation in modern micro-total-analytical systems.

High-efficiency grating coupler based on fast directional optimization and robust layout strategy in 130†nm CMOS process.

We experimentally demonstrated a high-efficiency grating coupler by combining an interleaved etch and apodized structure for fiber-to-chip coupling. The grating coupler was optimized using the fast directional optimization method to achieve apodization. The grating coupler utilized a layout strategy involving an extended mask to avoid alignment errors for a multi-etch structure. The coupling efficiency was measured to be -2.2 dB at a wavelength of 1549 nm with a 3 dB bandwidth of 47 nm. The grating coupler, having no gold reflector, subwavelength index matching structure, or additional material layers, was fabricated using a commercial silicon photonics process with a minimum feature size of 140 nm. This grating coupler design provides a robust and effective coupling scheme and the proposed method can be employed to adopt the design in accordance with standard foundry design rules.