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Single-atom catalysts (SACs) represent the ultimate size limit of nanoscale catalysts, combining the advantages of homogeneous and heterogeneous catalysts. SACs have isolated single-atom active sites that exhibit high atomic utilization efficiency, unique catalytic activity, and selectivity. Over the past few decades, synchrotron radiation techniques have played a crucial role in studying single-atom catalysis by identifying catalyst structures and enabling the understanding of reaction mechanisms. The profound comprehension of spectroscopic techniques and characteristics pertaining to SACs is important for exploring their catalytic activity origins and devising high-performance and stable SACs for industrial applications. In this review, we provide a comprehensive overview of the recent advances in X-ray based synchrotron radiation techniques for structural characterization and in situ / operando observation of SACs under reaction conditions. We emphasize the correlation between spectral fine features and structural characteristics of SACs, along with their analytical limitations. The development of IMST with spatial and temporal resolution is also discussed along with their significance in revealing the structural characteristics and reaction mechanisms of SACs. Additionally, this review explores the study of active center states using spectral fine characteristics combined with theoretical simulations, as well as spectroscopic analysis strategies utilizing machine learning methods to address challenges posed by atomic distribution inhomogeneity in SACs while envisaging potential applications integrating artificial intelligence seamlessly with experiments for real-time monitoring of single-atom catalytic processes.

Single-atom catalysts (SACs) have attracted considerable research interest owing to their combined merits of homogeneous and heterogeneous catalysts. However, the uniform and isolated active sites of SACs fall short in catalysing complex chemical processes that simultaneously involve multiple intermediates. In this Review, we highlight an emerging class of catalysts with adjacent binary active centres, which is called integrative catalytic pairs (ICPs), showing not only atomic-scale site-to-site electronic interactions but also synergistic catalytic effects. Compared with SACs or their derivative dual-atom catalysts (DACs), multi-interactive intermediates on ICPs can overcome kinetic barriers, adjust reaction pathways and break the universal linear scaling relations as the smallest active units. Starting from this active-site design principle, each single active atom can be considered as a brick to further build integrative catalytic clusters (ICCs) with desirable configurations, towards trimer or even larger multi-atom units depending on the requirement of a given reaction., (© 2024. Springer Nature Limited.)

Nitrite (NO 2 - ) is present in a variety of foods, but the excessive intake of NO 2 - can indirectly lead to carcinogenic, teratogenic, mutagenicity and other risks to the human body. Therefore, the detection of NO 2 - is crucial for maintaining human health. In this study, an integrated array sensor for NO 2 - detection is developed based on molybdenum single atom material (IMS Mo-SAC ) using high-resolution electrohydrodynamic (EHD) printing technology. The sensor comprises three components: a printed electrode array, multichannels designed on polydimethylsiloxane (PDMS) and an electronic signal process device with bluetooth. By utilizing Mo-SAC to facilitate electron transfer during the redox reaction, rapid and efficient detection of NO 2 - can be achieved. The sensor has a wide linear range of 0.1 μM-107.8 mM, a low detection limit of 33 nM and a high sensitivity of 0.637 mA -1 mM -1 cm -2 . Furthermore, employing this portable array sensor allows simultaneously measurements of NO 2 - concentrations in six different foods samples with acceptable recovery rates. This array sensor holds great potential for detecting of small molecules in various fields., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Urinary tract infections (UTIs), which can lead to pyelonephritis, urosepsis, and even death, are among the most prevalent infectious diseases worldwide, with a notable increase in treatment costs due to the emergence of drug-resistant pathogens. Current diagnostic strategies for UTIs, such as urine culture and flow cytometry, require time-consuming protocols and expensive equipment. We present here a machine learning-assisted colorimetric sensor array based on recognition of ligand-functionalized Fe single-atom nanozymes (SANs) for the identification of microorganisms at the order, genus, and species levels. Colorimetric sensor arrays are built from the SAN Fe 1 -NC functionalized with four types of recognition ligands, generating unique microbial identification fingerprints. By integrating the colorimetric sensor arrays with a trained computational classification model, the platform can identify more than 10 microorganisms in UTI urine samples within 1 h. Diagnostic accuracy of up to 97% was achieved in 60 UTI clinical samples, holding great potential for translation into clinical practice applications.

Constructing atomic catalytic pair emerges as an attractive strategy to achieve better catalytic performance. Herein, an atomic Ir 1 ─P 1 /NPG catalyst with asymmetric Ir─N 2 P 1 sites that delivers superb activity and selectivity for hydrogenation of various functionalized nitrostyrene is reported. In the hydrogenation reaction of 3-nitrostyrene, Ir 1 ─P 1 /NPG (NPG refers to N, P-codoped graphene) shows a turnover frequency of 1197 h -1 , while the reaction cannot occur over Ir 1 /NG (NG refers to N-doped graphene). Compared to Ir 1 /NG, the charge density of the Ir site in Ir 1 ─P 1 /NPG is greatly elevated, which is conducive to H 2 dissociation. Moreover, as revealed by density functional theory calculations and poisoning experiments, the P site in Ir 1 ─P 1 /NPG is found able to bind nitrostyrene, while the neighboring Ir site provides H to reduce the nitro group in chemoselective hydrogenation of nitrostyrene. This work offers a successful example of establishing atomic catalytic pair for driving important chemical reactions, paving the way for the development of more advanced catalysts to further improve the catalytic performance., (© 2023 Wiley‐VCH GmbH.)

Glycerol is a byproduct of biodiesel production. Selective photoelectrochemical oxidation of glycerol to high value-added chemicals offers an economical and sustainable approach to transform renewable feedstock as well as store green energy at the same time. In this work, we synthesized monoclinic WO 3 nanosheets with exposed (002) facets, which could selectively oxidize glycerol to glyceric acid (GLYA) with a photocurrent density of 1.7 mA cm -2 , a 73 % GLYA selectivity and a 39 % GLYA Faradaic efficiency at 0.9 V vs. reversible hydrogen electrode (RHE) under AM 1.5G illumination (100 mW cm -2 ). Compared to (200) facets exposed WO 3 , a combination of experiments and theoretical calculations indicates that the superior performance of selective glycerol oxidation mainly originates from the better charge separation and prolonged carrier lifetime resulted from the plenty of surface trapping states, lower energy barrier of the glycerol-to-GLYA reaction pathway, more abundant active sites and stronger oxidative ability of photogenerated holes on the (002) facets exposed WO 3 . Our findings show great potential to significantly contribute to the sustainable and environmentally friendly chemical processes via designing high performance photoelectrochemical cell via facet engineering for renewable feedstock transformation., (© 2023 Wiley-VCH GmbH.)

Unraveling the configuration-activity relationship and synergistic enhancement mechanism (such as real active center, electron spin-state, and d-orbital energy level) for triatomic catalysts, as well as their intrinsically bifunctional oxygen electrocatalysis, is a great challenge. Here we present a triatomic catalyst (TAC) with a trinuclear active structure that displays extraordinary oxygen electrocatalysis for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), greatly outperforming the counterpart of single-atom and diatomic catalysts. The aqueous Zn-air battery (ZAB) equipped with a TAC-based cathode exhibits extraordinary rechargeable stability and ultrarobust cycling performance (1970 h/3940 cycles at 2 mA cm -2 , 125 h/250 cycles at 10 mA cm -2 with negligible voltage decay), and the quasi-solid-state ZAB displays outstanding rechargeability and low-temperature adaptability (300 h/1800 cycles at 2 mA cm -2 at -60 °C), outperforming other state-of-the-art ZABs. The experimental and theoretical analyses reveal the symmetry-breaking CoN 4 configuration under incorporation of neighboring metal atoms (Fe and Cu), which leads to d-orbital modulation, a low-shift d band center, weakened binding strength to the oxygen intermediates, and decreased energy barrier for bifunctional oxygen electrocatalysis. This rational tricoordination design as well as an in-depth mechanism analysis indicate that hetero-TACs can be promisingly applied in various electrocatalysis applications.

Materials with various single-transition metal atoms dispersed in nitrogenated carbons (M─N─C, M = Fe, Co, and Ni) are synthesized as cathodes to investigate the electrocatalytic behaviors focusing on their enhancement mechanism for performance of Li-S batteries. Results indicate that the order of both electrocatalytic activity and rate capacity for the M─N─C catalysts is Co > Ni > Fe, and the Co─N─C delivers the highest capacity of 1100 mAh g -1 at 1 C and longtime stability at a decay rate of 0.05% per cycle for 1000 cycles, demonstrating excellent battery performance. Theoretical calculations for the first time reveal that M─N─N─C catalysts enable direct conversion of Li 2 S 6 to Li 2 S rather than Li 2 S 4 to Li 2 S by stronger adsorption with Li 2 S 6 , which also has an order of Co > Ni > Fe. And Co─N─C has the strongest adsorption energy, not only rendering the highest electrocatalytic activity, but also depressing the polysulfides' dissolution into electrolyte for the longest cycle life. This work offers an avenue to design the next generation of highly efficient sulfur cathodes for high-performance Li-S batteries, while shedding light on the fundamental insight of single metal atomic catalytic effects on Li-S batteries., (© 2023 Wiley-VCH GmbH.)

Single-atom catalysts exhibit superior CO 2 -to-CO catalytic activity, but poor kinetics of proton-coupled electron transfer (PCET) steps still limit the overall performance toward the industrial scale. Here, we constructed a Fe-P atom paired catalyst onto nitrogen doped graphitic layer (Fe 1 /PNG) to accelerate PCET step. Fe 1 /PNG delivers an industrial CO current of 1 A with FE CO over 90 % at 2.5 V in a membrane-electrode assembly, overperforming the CO current of Fe 1 /NG by more than 300 %. We also decrypted the synergistic effects of the P atom in the Fe-P atom pair using operando techniques and density functional theory, revealing that the P atom provides additional adsorption sites for accelerating water dissociation, boosting the hydrogenation of CO 2 , and enhancing the activity of CO 2 reduction. This atom-pair catalytic strategy can modulate multiple reactants and intermediates to break through the inherent limitations of single-atom catalysts., (© 2023 Wiley-VCH GmbH.)

In this work, via engineering the conformation of cobalt active center in cobalt phthalocyanine molecular catalyst, the catalytic efficiency of electrochemical carbon monoxide reduction to methanol can be dramatically tuned. Based on a collection of experimental investigations and density functional theory calculations, it reveals that the electron rearrangement of the Co 3d orbitals of cobalt phthalocyanine from the low-spin state (S = 1/2) to the high-spin state (S = 3/2), induced by molecular conformation change, is responsible for the greatly enhanced CO reduction reaction performance. Operando attenuated total reflectance surface-enhanced infrared absorption spectroscopy measurements disclose accelerated hydrogenation of CORR intermediates, and kinetic isotope effect validates expedited proton-feeding rate over cobalt phthalocyanine with high-spin state. Further natural population analysis and density functional theory calculations demonstrate that the high spin Co 2+ can enhance the electron backdonation via the d xz /d yz -2π* bond and weaken the C-O bonding in *CO, promoting hydrogenation of CORR intermediates., (© 2023. Springer Nature Limited.)

Precise structural control has attracted tremendous interest in pursuit of the tailoring of physical properties. Here, this work shows that through strong ligand-mediated interfacial energy control, Au-Cu 2 O dumbbell structures where both the Au nanorod (AuNR) and the partially encapsulating Cu 2 O domains are highly crystalline. The synthetic advance allows physical separation of the Au and Cu 2 O domains, in addition to the use of long nanorods with tunable absorption wavelength, and the crystalline Cu 2 O domain with well-defined facets. The interplay of plasmon and Schottky effects boosts the photocatalytic performance in the model photodegradation of methyl orange, showing superior catalytic efficiency than the AuNR@Cu 2 O core-shell structures. In addition, compared to the typical core-shell structures, the AuNR-Cu 2 O dumbbells can effectively electrochemically catalyze the CO 2 to C 2+ products (ethanol and ethylene) via a cascade reaction pathway. The excellent dual function of both photo- and electrocatalysis can be attributed to the fine physical separation of the crystalline Au and Cu 2 O domains., (© 2023 Wiley-VCH GmbH.)

The design of active and low-cost electrocatalyst for hydrogen evolution reaction (HER) is the key to achieving a clean hydrogen energy infrastructure. The most successful design principle of hydrogen electrocatalyst is the activity volcano plot, which is based on Sabatier principle and has been used to understand the exceptional activity of noble metal and design of metal alloy catalysts. However, this application of volcano plot in designing single-atom electrocatalysts (SAEs) on nitrogen doped graphene (TM/N 4 C catalysts) for HER has been less successful due to the nonmetallic nature of the single metal atom site. Herein, by performing ab initio molecular dynamics simulations and free energy calculations on a series of SAEs systems (TM/N 4 C with TM = 3d, 4d, or 5d metals), we find that the strong charge-dipole interaction between the negatively charged *H intermediate and the interfacial H 2 O molecules could alter the transition path of the acidic Volmer reaction and dramatically raise its kinetic barrier, despite its favorable adsorption free energy. Such kinetic hindrance is also experimentally confirmed by electrochemical measurements. By combining the hydrogen adsorption free energy and the physics of competing interfacial interactions, we propose a unifying design principle for engineering the SAEs used for hydrogen energy conversion, which incorporates both thermodynamic and kinetic considerations and allows going beyond the activity volcano model.

Simultaneous detection of dihydroxybenzene isomers including hydroquinone (HQ), catechol (CC), and resorcinol (RS) is significant for water quality control as they are highly toxic and often coexist. However, it is a great challenge to realize their accurate and simultaneous detection due to their similarity in structure and properties. Herein, an electrochemical flexible strip with single-atom cobalt (SA-Co/NG) was constructed through high-resolution electrohydrodynamic (EHD) printing for dihydroxybenzene isomer's simultaneous detection. Results showed that the provided SA-Co/NG strip exhibited excellent sensing performance with reliable repeatability, reproducibility, long-term stability, and flexibility. Linear ranges of 0.50-31 745 μM, 0.50-5909 μM, and 0.50-153.5 μM were achieved for HQ, CC, and RS, respectively, with a detection limit of 0.164 μM. Based on the experimental data, the mechanism concerning SA-Co/NG catalytic activity towards HQ can be deduced, starting from the combination of Co* and OH - in water, followed by the formation of Co-OH-dihydroxybenzene, and finally leading to O-H bond dissociation to generate benzoquinone. As for CC or RS, pyridinic N or CO synergistic with a single Co atom catalyzes their oxidation. Besides, the printed flexible SA-Co/NG strip further demonstrates the accurate and simultaneous detection of HQ, CC, and RS in textile wastewater, proposing a powerful practical application.

In the electrochemical CO 2 reduction reaction (CO 2 RR), CO 2 activation is always the first step, followed by the subsequent hydrogenation. The catalytic performance of CO 2 RR is intrinsically restricted by the competition between molecular CO 2 activation and CO 2 reduction product release. Here, we design a heteronuclear Fe 1 -Mo 1 dual-metal catalytic pair on ordered porous carbon that features a high catalytic performance for driving electrochemical CO 2 reduction to CO. Combining real-time near-ambient pressure X-ray photoelectron spectroscopy, operando 57 Fe Mössbauer spectroscopy, and in situ attenuated total reflectance surface-enhanced infrared absorption spectroscopy measurements with density functional theory calculations, chemical adsorption of CO 2 is observed on the Fe 1 -Mo 1 catalytic pair through a bridge configuration, which prompts the bending of the CO 2 molecule for CO 2 activation and then facilitates the subsequent hydrogeneration reaction. More importantly, the dynamic adsorption configuration transition from the bridge configuration of CO 2 on Fe 1 -Mo 1 to the linear configuration of CO on the Fe 1 center results in breaking the scaling relationship in CO 2 RR, simultaneously promoting the CO 2 activation and the CO release.

Nitric oxide (NO) exhibits a crucial role in various versatile and distinct physiological functions. Hence, its real-time sensing is highly important. Herein, we developed an integrated nanoelectronic system comprising a cobalt single-atom nanozyme (Co-SAE) chip array sensor and an electronic signal processing module (IND Co-SAE ) for both in vitro and in vivo multichannel qualifying of NO in normal and tumor-bearing mice. The high atomic utilization and catalytic activity of Co-SAE endowed an ultrawide linear range for NO varying from 36 to 4.1 × 10 5 nM with a low detection limit of 12 nM. Combining in situ attenuated total reflectance surface enhanced infrared spectroscopy (ATR-SEIRAS) measurements and density function calculation revealed the activating mechanism of Co-SAE toward NO. The NO adsorption on an active Co atom forms *NO, followed by the reaction between *NO and OH - , which could help design relevant nanozymes. Further, we investigated the NO-producing behaviors of various organs of both normal and tumor-bearing mice using the proposed device. We also evaluated the NO yield produced by the wounded mouse using the designed device and found it to be approximately 15 times that of the normal mouse. This study bridges the technical gap between a biosensor and an integrated system for molecular analysis in vitro and in vivo . The as-fabricated integrated wireless nanoelectronic system with multiple test channels significantly improved the detection efficiency, which can be widely used in designing other portable sensing devices with multiplexed analysis capability.

Polymer electrolyte membrane water electrolysis (PEMWE) has been regarded as a promising technology for renewable hydrogen production. However, acidic oxygen evolution reaction (OER) catalysts with long-term stability impose a grand challenge in its large-scale industrialization. In this review, critical factors that may lead to catalyst's instability in couple with potential solutions are comprehensively discussed, including mechanical peeling, substrate corrosion, active-site over-oxidation/dissolution, reconstruction, oxide crystal structure collapse through the lattice oxygen-participated reaction pathway, etc. Last but not least, personal prospects are provided in terms of rigorous stability evaluation criteria, in situ/operando characterizations, economic feasibility and practical electrolyzer consideration, highlighting the ternary relationship of structure evolution, industrial-relevant activity and stability to serve as a roadmap towards the ultimate application of PEMWE., (© 2022 Wiley-VCH GmbH.)

Designing and synthesizing highly efficient and stable electrocatalysts for hydrogen evolution reaction (HER) is important for realizing the hydrogen economy. Tuning the electronic structure of the electrocatalysts is essential to achieve optimal HER activity, and interfacial engineering is an effective strategy to induce electron transfer in a heterostructure interface to optimize HER kinetics. In this study, ultrafine RhP 2 /Rh nanoparticles are synthesized with a well-defined semiconductor-metal heterointerface embedded in N,P co-doped graphene (RhP 2 /Rh@NPG) via a one-step pyrolysis. RhP 2 /Rh@NPG exhibits outstanding HER performances under all pH conditions. Electrochemical characterization and first principles density functional theory calculations reveal that the RhP 2 /Rh heterointerface induces electron transfer from metallic Rh to semiconductive RhP 2 , which increases the electron density on the Rh atoms in RhP 2 and weakens the hydrogen adsorption on RhP 2 , thereby accelerating the HER kinetics. Moreover, the interfacial electron transfer activates the dual-site synergistic effect of Rh and P of RhP 2 in neutral and alkaline environments, thereby promoting reorganization of interfacial water molecules for faster HER kinetics., (© 2022 Wiley-VCH GmbH.)

Adsorption energy (AE) of reactive intermediate is currently the most important descriptor for electrochemical reactions (e.g., water electrolysis, hydrogen fuel cell, electrochemical nitrogen fixation, electrochemical carbon dioxide reduction, etc.), which can bridge the gap between catalyst's structure and activity. Tracing the history and evolution of AE can help to understand electrocatalysis and design optimal electrocatalysts. Focusing on oxygen electrocatalysis, this review aims to provide a comprehensive introduction on how AE is selected as the activity descriptor, the intrinsic and empirical relationships related to AE, how AE links the structure and electrocatalytic performance, the approaches to obtain AE, the strategies to improve catalytic activity by modulating AE, the extrinsic influences on AE from the environment, and the methods in circumventing linear scaling relations of AE. An outlook is provided at the end with emphasis on possible future investigation related to the obstacles existing between adsorption energy and electrocatalytic performance.

Introduction: Legume crops are an important source of protein and oil for human health and in fixing atmospheric N 2 for soil enrichment. With an objective to accelerate much-needed genetic analyses and breeding applications, draft genome assemblies were generated in several legume crops; many of them are not high quality because they are mainly based on short reads. However, the superior quality of genome assembly is crucial for a detailed understanding of genomic architecture, genome evolution, and crop improvement., Objectives: Present study was undertaken with an objective of developing improved chromosome-length genome assemblies in six different legumes followed by their systematic investigation to unravel different aspects of genome organization and legume evolution., Methods: We employed in situ Hi-C data to improve the existing draft genomes and performed different evolutionary and comparative analyses using improved genome assemblies., Results: We have developed chromosome-length genome assemblies in chickpea, pigeonpea, soybean, subterranean clover, and two wild progenitor species of cultivated groundnut (A. duranensis and A. ipaensis). A comprehensive comparative analysis of these genome assemblies offered improved insights into various evolutionary events that shaped the present-day legume species. We highlighted the expansion of gene families contributing to unique traits such as nodulation in legumes, gravitropism in groundnut, and oil biosynthesis in oilseed legume crops such as groundnut and soybean. As examples, we have demonstrated the utility of improved genome assemblies for enhancing the resolution of "QTL-hotspot" identification for drought tolerance in chickpea and marker-trait associations for agronomic traits in pigeonpea through genome-wide association study. Genomic resources developed in this study are publicly available through an online repository, 'Legumepedia'., Conclusion: This study reports chromosome-length genome assemblies of six legume species and demonstrates the utility of these assemblies in crop improvement. The genomic resources developed here will have significant role in accelerating genetic improvement applications of legume crops., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021. Production and hosting by Elsevier B.V.)

Inducing the surface enrichment of active noble metal can not only help to stabilize the catalyst but also modify the catalytic performance of the catalyst through electronic and geometric effects. Herein, we report the in situ surface enrichment of Ir on IrRu alloy during the oxygen evolution reaction (OER). The surface enrichment of Ir was probed by ex situ high-resolution transmission electron microscopy (HRTEM), in situ X-ray absorption spectroscopy (XAS), and electrochemical Cu stripping, leading to complementary characterizations of the dynamic reconstruction of the IrRu alloy during OER. Guided by the density functional theory (DFT), an IrRu alloy with low Ir content (20 wt%) was constructed, which displayed a low overpotential of only 230 mV to deliver an OER current density of 10 mA cm -2 in 0.1 M HClO 4 solution and maintained stable performance for over 20 h. To investigate the practical application potential, a proton exchange membrane (PEM) water electrolyzer using the IrRu alloy as the anode catalyst was assembled, which required a low cell voltage of only 1.48 V to generate a current density of 1 A cm -2 ., Competing Interests: Authors declare no competing interests., (This journal is © The Royal Society of Chemistry.)

Two-electron oxygen photoreduction to hydrogen peroxide (H 2 O 2 ) is seriously inhibited by its sluggish charge kinetics. Herein, a polarization engineering strategy is demonstrated by grafting (thio)urea functional groups onto covalent triazine frameworks (CTFs), giving rise to significantly promoted charge separation/transport and obviously enhanced proton transfer. The thiourea-functionalized CTF (Bpt-CTF) presents a substantial improvement in the photocatalytic H 2 O 2 production rate to 3268.1 µmol h -1 g -1 with no sacrificial agents or cocatalysts that is over an order of magnitude higher than unfunctionalized CTF (Dc-CTF), and a remarkable quantum efficiency of 8.6% at 400 nm. Mechanistic studies reveal the photocatalytic performance is attributed to the prominently enhanced two-electron oxygen reduction reaction by forming endoperoxide at the triazine unit and highly concentrated holes at the thiourea site. The generated O 2 from water oxidation is subsequently consumed by the oxygen reduction reaction (ORR), thereby boosting overall reaction kinetics. The findings suggest a powerful functional-groups-mediated polarization engineering method for the development of highly efficient metal-free polymer-based photocatalysts., (© 2022 Wiley-VCH GmbH.)

A high-throughput screening machine learning model for mitochondrial function was constructed, and compounds of Aco-niti Lateralis Radix Praeparata were predicted. Deoxyaconitine with the highest score and benzoylmesaconine with the lowest score among the compounds screened by the model were selected for mitochondrial mechanism analysis. Mitochondrial function data were collected from PubChem and Tox21 databases. Random forest and gradient boosted decision tree algorithms were separately used for mo-deling, and ECFP4(extended connectivity fingerprint, up to four bonds) and Mordred descriptors were employed for training, respectively. Cross-validation test was carried out, and balanced accuracy(BA) and overall accuracy were determined to evaluate the performance of different combinations of models and obtain the optimal algorithm and hyperparameters for modeling. The data of Aconiti Lateralis Radix Praeparata compounds in TCMSP database were collected, and after prediction and screening by the constructed high-throughput screening machine learning model, deoxyaconitine and benzoylmesaconine were selected to measure mitochondrial membrane potential, reactive oxygen species(ROS) level and protein expression of B-cell lymphoma 2(Bcl-2), Bcl-2-associated X protein(Bax) and peroxisome proliferator-activated receptor-γ-coactivator 1α(PGC-1α). The results showed that the model constructed using gradient boosted decision tree+Mordred algorithm performed better, with a cross-validation BA of 0.825 and a test set accuracy of 0.811. Deoxyaconitine and benzoylmesaconine changed the ROS level(P<0.001), mitochondrial membrane potential(P<0.001), and protein expression of Bcl-2(P<0.001, P<0.01) and Bax(P<0.001), and deoxyaconitine increased the expression of PGC-1α protein(P<0.01). The high-throughput screening model for mitochondrial function constructed by gradient boosted decision tree+Mordred algorithm was more accurate than that by random forest+ECFP4 algorithm, which could be used to build an algorithm model for subsequent research. Deoxyaconitine and benzoylmesaconine affected mitochondrial function. However, deoxyaconitine with higher score also affected mitochondrial biosynthesis by regulating PGC-1α protein.

Noble metals have an irreplaceable role in catalyzing electrochemical reactions. However, large overpotential and poor long-term stability still prohibit their usage in many reactions (e.g., oxygen evolution/reduction). With regard to the low natural abundance, the improvement of their overall electrocatalytic performance (activity, selectivity, and stability) was urgently necessary. Herein, strong metal-support interaction (SMSI) was modulated through an unprecedented time-dependent mechanical milling method on Pd-loaded oxygenated TiC electrocatalysts. The encapsulation of Pd surfaces with reduced TiO 2- x overlayers is precisely controlled by the mechanical milling time. This encapsulation induced a valence band restructuring and lowered the d-band center of surface Pd atoms. For hydrogen peroxide electrosynthesis through the two-electron oxygen reduction reaction (ORR), these electronic and geometric modifications resulted in optimal adsorption energies of reaction intermediates. Thus, SMSI phenomena not only enhanced electrocatalytic activity and selectivity but also created an encapsulating oxide overlayer that protected the Pd species, increasing its long-term stability. This SMSI induced by mechanical milling was also extended to other noble metal systems, showing great promise for the large-scale production of highly stable and tunable electrocatalysts.

Single-atom catalysis efficiently exposes the catalytic sites to reactant molecules while rendering opportunity to investigate the catalysis mechanisms at atomic levels for scientific insights. Here, for the first time, atomically dispersed Co atoms are synthesized as biomimetic "enzymes" to monitor superoxide anions (O 2 •- ), delivering ultraordinary high sensitivity (710.03 μA·μM -1 ·cm -2 ), low detection limit (1.5 nM), and rapid response time (1.2 s), ranking the best among all the reported either bioenzymatic or biomimetic O 2 •- biosensors. The sensor is further successfully employed to real-time monitor O 2 •- released from living cells. Moreover, theoretical calculation and analysis associated with experimental results discover that a mode of end adsorption of the negatively charged O 2 •- on the Co 3+ atom rather than a bridge or/and side adsorption of the two atoms of O 2 •- on two Co 3+ atoms, respectively, plays an important role in the single-atomic catalysis toward O 2 •- oxidation, which not only facilitates faster electron transfer but also offers better selectivity. This work holds great promise for an inexpensive and sensitive atomic biomimetic O 2 •- sensor for bioresearch and clinic diagnosis, while revealing that the adsorption mode plays a critical role in single-atom catalysis for a fundamental insight.

Single-atom catalysts have attracted numerous attention due to the high utilization of metallic atoms, abundant active sites, and highly catalytic activities. Herein, a single-atom ruthenium biomimetic enzyme (Ru-Ala-C 3 N 4 ) is prepared by dispersing Ru atoms on a carbon nitride support for the simultaneous electrochemical detection of dopamine (DA) and uric acid (UA), which are coexisting important biological molecules involving in many physiological and pathological aspects. The morphology and elemental states of the single-atom Ru catalyst are studied by transmission electron microscopy, energy dispersive X-ray elemental mapping, high-angle annular dark field-scanning transmission electron microscopy, and high-resolution X-ray photoelectron spectroscopy. Results show that Ru atoms atomically disperse throughout the C 3 N 4 support by Ru-N chemical bonds. The electrochemical characterizations indicate that the Ru-Ala-C 3 N 4 biosensor can simultaneously detect the oxidation of DA and UA with a separation of peak potential of 180 mV with high sensitivity and excellent selectivity. The calibration curves for DA and UA range from 0.06 to 490 and 0.5 to 2135 μM with detection limits of 20 and 170 nM, respectively. Moreover, the biosensor was applied to detect DA and UA in real biological serum samples using the standard addition method with satisfactory results.

Uric acid (UA) detection is essential in diagnosis of arthritis, preeclampsia, renal disorder, and cardiovascular diseases, but it is very challenging to realize the required wide detection range and low detection limit. We present here a single-atom catalyst consisting of Co (II) atoms coordinated by an average of 3.4 N atoms on an N-doped graphene matrix (A-Co-NG) to build an electrochemical biomimetic sensor for UA detection. The A-Co-NG sensor achieves a wide detection range over 0.4-41,950 μM and an extremely low detection limit of 33.3 ± 0.024 nM, which are much better than previously reported sensors based on various nanostructured materials. Besides, the A-Co-NG sensor also demonstrates its accurate serum diagnosis for UA for its practical application. Combination of experimental and theoretical calculation discovers that the catalytic process of the A-Co-NG toward UA starts from the oxidation of Co species to form a Co 3+ -OH-UA*, followed by the generation of Co 3+ -OH +  * UA_H, eventually leading to N-H bond dissociation for the formation of oxidized UA molecule and reduction of oxidized Co 3+ to Co 2+ for the regenerated A-Co-NG. This work provides a promising material to realize UA detection with wide detection range and low detection limit to meet the practical diagnosis requirements, and the proposed sensing mechanism sheds light on fundamental insights for guiding exploration of other biosensing processes.

Designing effective electrocatalysts for the carbon dioxide reduction reaction (CO 2 RR) is an appealing approach to tackling the challenges posed by rising CO 2 levels and realizing a closed carbon cycle. However, fundamental understanding of the complicated CO 2 RR mechanism in CO 2 electrocatalysis is still lacking because model systems are limited. We have designed a model nickel single-atom catalyst (Ni SAC) with a uniform structure and well-defined Ni-N 4 moiety on a conductive carbon support with which to explore the electrochemical CO 2 RR. Operando X-ray absorption near-edge structure spectroscopy, Raman spectroscopy, and near-ambient X-ray photoelectron spectroscopy, revealed that Ni + in the Ni SAC was highly active for CO 2 activation, and functioned as an authentic catalytically active site for the CO 2 RR. Furthermore, through combination with a kinetics study, the rate-determining step of the CO 2 RR was determined to be *CO 2 - +H + →*COOH. This study tackles the four challenges faced by the CO 2 RR; namely, activity, selectivity, stability, and dynamics., (© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

NiFe-based layered double hydroxides (LDHs) are among the most efficient oxygen evolution reaction (OER) catalysts in alkaline medium, but their long-term OER stabilities are questionable. In this work, it is demonstrated that the layered structure makes bulk NiFe LDH intrinsically not stable in OER and the deactivation mechanism of NiFe LDH in OER is further revealed. Both operando electrochemical and structural characterizations show that the interlayer basal plane in bulk NiFe LDH contributes to the OER activity, and the slow diffusion of proton acceptors (e.g., OH - ) within the NiFe LDH interlayers during OER causes dissolution of NiFe LDH and therefore decrease in OER activity with time. To improve diffusion of proton acceptors, it is proposed to delaminate NiFe LDH into atomically thin nanosheets, which is able to effectively improve OER stability of NiFe LDH especially at industrial operating conditions such as elevated operating temperatures (e.g., at 80 °C) and large current densities (e.g., at 500 mA cm -2 )., (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

It is highly profitable to transform glycerol - the main by-product from biodiesel production to high value-added chemicals. In this work, we develop a photoelectrochemical system based on nanoporous BiVO 4 for selective oxidation of glycerol to 1,3-dihydroxyacetone - one of the most valuable derivatives of glycerol. Under AM 1.5G front illumination (100 mW cm -2 ) in an acidic medium (pH = 2) without adscititious oxidant, the nanoporous BiVO 4 photoanode achieves a glycerol oxidation photocurrent density of 3.7 mA cm -2 at a potential of 1.2 V versus RHE with 51% 1,3-dihydroxyacetone selectivity, equivalent to a production rate of 200 mmol of 1,3-dihydroxyacetone per m 2 of illumination area in one hour.

It is well known that high-risk human papilloma virus (HR-HPV) infection is strongly associated with cervical cancer and E7 was identified as one of the key initiators in HPV-mediated carcinogenesis. Here we show that lactate dehydrogenase A (LDHA) preferably locates in the nucleus in HPV16-positive cervical tumors due to E7-induced intracellular reactive oxygen species (ROS) accumulation. Surprisingly, nuclear LDHA gains a non-canonical enzyme activity to produce α-hydroxybutyrate and triggers DOT1L (disruptor of telomeric silencing 1-like)-mediated histone H3K79 hypermethylation, resulting in the activation of antioxidant responses and Wnt signaling pathway. Furthermore, HPV16 E7 knocking-out reduces LDHA nuclear translocation and H3K79 tri-methylation in K14-HPV16 transgenic mouse model. HPV16 E7 level is significantly positively correlated with nuclear LDHA and H3K79 tri-methylation in cervical cancer. Collectively, our findings uncover a non-canonical enzyme activity of nuclear LDHA to epigenetically control cellular redox balance and cell proliferation facilitating HPV-induced cervical cancer development.

Aim: To uncover the underlying pathogenesis of thyroid associated ophthalmopathy (TAO) and explore potential biomarkers of this disease., Methods: The expression profile GSE9340, which was downloaded from Gene Expression Omnibus database, included 18 specimens from 10 TAO patients and 8 hyperthyroidism patients without ophthalmopathy. The platform was HumanRef-8 v2 Expression BeadChip. Raw data were normalized using preprocess. Core package and the differentially expressed genes (DEGs) were identified based on t -test with limma package of R. Functional enrichment analyses were performed recruiting the DAVID tool. Based on STRING database, a protein-protein interaction (PPI) network was constructed, from which a module was extracted. The functional enrichment for genes in the module was performed by the BinGO plugin., Results: In total, 861 DEGs (433 up-regulated and 428 down-regulated) between TAO patients and hyperthyroidism patients without ophthalmopathy were identified. Crucial nodes in the PPI network included TPX2, CDCA5, PRC1, KIF23 and MKI67, which were also remarkable in the module and all enriched in cell cycle process. Additionally, MKI67 was highly correlated with TAO. Besides, the DEGs of GTF2F1 , SMC3 , USF1 and ZNF263 were predicted as transcription factors (TFs)., Conclusion: Several crucial genes are identified such as TPX2 , CDCA5 , PRC1 and KIF23 , which all might play significant roles in TAO via the regulation of cell cycle process. Regulatory relationships between TPX2 and CDCA5 as well as between PRC1 and KIF23 may exist. Additionally, MKI67 may be a potent biomarker of TAO, and SMC3 and ZNF263 may exert their roles as TFs in TAO progression.

Aberrant centrosome organisation with ensuing alterations of microtubule nucleation capacity enables tumour cells to proliferate and invade despite increased genomic instability. CEP192 is a key factor in the initiation process of centrosome duplication and in the control of centrosome microtubule nucleation. However, regulatory means of CEP192 have remained unknown. Here, we report that FBXL13, a binding determinant of SCF (SKP1-CUL1-F-box)-family E3 ubiquitin ligases, is enriched at centrosomes and interacts with the centrosomal proteins Centrin-2, Centrin-3, CEP152 and CEP192. Among these, CEP192 is specifically targeted for proteasomal degradation by FBXL13. Accordingly, induced FBXL13 expression downregulates centrosomal γ-tubulin and disrupts centrosomal microtubule arrays. In addition, depletion of FBXL13 induces high levels of CEP192 and γ-tubulin at the centrosomes with the consequence of defects in cell motility. Together, we characterise FBXL13 as a novel regulator of microtubule nucleation activity and highlight a role in promoting cell motility with potential tumour-promoting implications., (© 2018 The Authors.)

An increasing number of cases of herb-induced liver injury (HILI) have been reported, presenting new clinical challenges. In this study, taking Polygonum multiflorum Thunb (PmT) as an example, we proposed a computational systems toxicology approach to explore the molecular mechanisms of HILI. First, the chemical components of PmT were extracted from 3 main TCM databases as well as the literature related to natural products. Then, the known targets were collected through data integration, and the potential compound-target interactions (CTIs) were predicted using our substructure-drug-target network-based inference (SDTNBI) method. After screening for hepatotoxicity-related genes by assessing the symptoms of HILI, a compound-target interaction network was constructed. A scoring function, namely, Ascore, was developed to estimate the toxicity of chemicals in the liver. We conducted network analysis to determine the possible mechanisms of the biphasic effects using the analysis tools, including BiNGO, pathway enrichment, organ distribution analysis and predictions of interactions with CYP450 enzymes. Among the chemical components of PmT, 54 components with good intestinal absorption were used for analysis, and 2939 CTIs were obtained. After analyzing the mRNA expression data in the BioGPS database, 1599 CTIs and 125 targets related to liver diseases were identified. In the top 15 compounds, seven with Ascore values >3000 (emodin, quercetin, apigenin, resveratrol, gallic acid, kaempferol and luteolin) were obviously associated with hepatotoxicity. The results from the pathway enrichment analysis suggest that multiple interactions between apoptosis and metabolism may underlie PmT-induced liver injury. Many of the pathways have been verified in specific compounds, such as glutathione metabolism, cytochrome P450 metabolism, and the p53 pathway, among others. Hepatitis symptoms, the perturbation of nine bile acids and yellow or tawny urine also had corresponding pathways, justifying our method. In conclusion, this computational systems toxicology method reveals possible toxic components and could be very helpful for understanding the mechanisms of HILI. In this way, the method might also facilitate the identification of novel hepatotoxic herbs.

Dysregulation of hormone metabolism is implicated in human breast cancer. 17β-hydroxysteroid dehydrogenase type 4 (HSD17B4) catalyzes the conversion of estradiol (E2) to estrone (E1), and is associated with the pathogenesis and development of various cancers. Here we show that E1 upregulates HSD17B4 acetylation at lysine 669 (K669) and thereby promotes HSD17B4 degradation via chaperone-mediated autophagy (CMA), while a single mutation at K669 reverses the degradation and confers migratory and invasive properties to MCF7 cells upon E1 treatment. CREBBP and SIRT3 dynamically control K669 acetylation level of HSD17B4 in response to E1. More importantly, K669 acetylation is inversely correlated with HSD17B4 in human breast cancer tissues. Our study reveals a crosstalk between acetylation and CMA degradation in HSD17B4 regulation, and a critical role of the regulation in the malignant progression of breast cancer.

A number of important reactions such as the oxygen evolution reaction (OER) are catalyzed by transition metal oxides (TMOs), the surface reactivity of which is rather elusive. Therefore, rationally tailoring adsorption energy of intermediates on TMOs to achieve desirable catalytic performance still remains a great challenge. Here we show the identification of a general and tunable surface structure, coordinatively unsaturated metal cation (MCUS), as a good surface reactivity descriptor for TMOs in OER. Surface reactivity of a given TMO increases monotonically with the density of MCUS, and thus the increase in MCUS improves the catalytic activity for weak-binding TMOs but impairs that for strong-binding ones. The electronic origin of the surface reactivity can be well explained by a new model proposed in this work, wherein the energy of the highest-occupied d-states relative to the Fermi level determines the intermediates' bonding strength by affecting the filling of the antibonding states. Our model for the first time well describes the reactivity trends among TMOs, and would initiate viable design principles for, but not limited to, OER catalysts.

Besides the conventional carbon sources, acetyl-CoA has recently been shown to be generated from acetate in various types of cancers, where it promotes lipid synthesis and tumour growth. The underlying mechanism, however, remains largely unknown. We find that acetate induces a hyperacetylated state of histone H3 in hypoxic cells. Acetate predominately activates lipogenic genes ACACA and FASN expression by increasing H3K9, H3K27 and H3K56 acetylation levels at their promoter regions, thus enhancing de novo lipid synthesis, which combines with its function as the metabolic precursor for fatty acid synthesis. Acetyl-CoA synthetases (ACSS1, ACSS2) are involved in this acetate-mediated epigenetic regulation. More importantly, human hepatocellular carcinoma with high ACSS1/2 expression exhibit increased histone H3 acetylation and FASN expression. Taken together, this study demonstrates that acetate, in addition to its ability to induce fatty acid synthesis as an immediate metabolic precursor, also functions as an epigenetic metabolite to promote cancer cell survival under hypoxic stress.

Oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are critical to renewable energy conversion and storage technologies. Heteroatom-doped carbon nanomaterials have been reported to be efficient metal-free electrocatalysts for ORR in fuel cells for energy conversion, as well as ORR and OER in metal-air batteries for energy storage. We reported that metal-free three-dimensional (3D) graphene nanoribbon networks (N-GRW) doped with nitrogen exhibited superb bifunctional electrocatalytic activities for both ORR and OER, with an excellent stability in alkaline electrolytes (for example, KOH). For the first time, it was experimentally demonstrated that the electron-donating quaternary N sites were responsible for ORR, whereas the electron-withdrawing pyridinic N moieties in N-GRW served as active sites for OER. The unique 3D nanoarchitecture provided a high density of the ORR and OER active sites and facilitated the electrolyte and electron transports. As a result, the as-prepared N-GRW holds great potential as a low-cost, highly efficient air cathode in rechargeable metal-air batteries. Rechargeable zinc-air batteries with the N-GRW air electrode in a two-electrode configuration exhibited an open-circuit voltage of 1.46 V, a specific capacity of 873 mAh g(-1), and a peak power density of 65 mW cm(-2), which could be continuously charged and discharged with an excellent cycling stability. Our work should open up new avenues for the development of various carbon-based metal-free bifunctional electrocatalysts of practical significance.

Due to the limited electronic conductivity, the application of many metal oxides that may have attractive (photo)-electrochemical properties has been limited. Regarding these issues, incorporating low-dimensional conducting scaffolds into the electrodes or supporting the metal oxides onto the conducting networks are common approaches. However, some key electronic processes like interfacial charge transfer are far from being consciously concerned. Here we use a carbon-TiO2 contact as a model system to demonstrate the electronic processes occurring at the metal-semiconductor interface. To minimize the energy dissipation for fast transfer of electrons from semiconductor to carbon scaffolds, facilitating electron tunneling while avoiding high energy-consuming thermionic emission is desired, according to our theoretical simulation of the voltammetric behaviors. To validate this, we manage to sandwich ultrathin TiO2 interlayers with heavy electronic doping between the carbon conductors and dopant-free TiO2. The radially graded distribution of the electronic doping along the cross-sectional direction of carbon conductor realized by immobilizing the dopant species on the carbon surface can minimize the energy consumption for contacts to both the carbon and the dopant-free TiO2. Our strategy provides an important requirement for metal oxide electrode design.

A unique functional electrode made of hierarchal Ni-Mo-S nanosheets with abundant exposed edges anchored on conductive and flexible carbon fiber cloth, referred to as Ni-Mo-S/C, has been developed through a facile biomolecule-assisted hydrothermal method. The incorporation of Ni atoms in Mo-S plays a crucial role in tuning its intrinsic catalytic property by creating substantial defect sites as well as modifying the morphology of Ni-Mo-S network at atomic scale, resulting in an impressive enhancement in the catalytic activity. The Ni-Mo-S/C electrode exhibits a large cathodic current and a low onset potential for hydrogen evolution reaction in neutral electrolyte (pH ~7), for example, current density of 10 mA/cm(2) at a very small overpotential of 200 mV. Furthermore, the Ni-Mo-S/C electrode has excellent electrocatalytic stability over an extended period, much better than those of MoS2/C and Pt plate electrodes. Scanning and transmission electron microscopy, Raman spectroscopy, x-ray diffraction, x-ray photoelectron spectroscopy, and x-ray absorption spectroscopy were used to understand the formation process and electrocatalytic properties of Ni-Mo-S/C. The intuitive comparison test was designed to reveal the superior gas-evolving profile of Ni-Mo-S/C over that of MoS2/C, and a laboratory-scale hydrogen generator was further assembled to demonstrate its potential application in practical appliances.

Carbon nanotubes are promising materials for various applications. In recent years, progress in manufacturing and functionalizing carbon nanotubes has been made to achieve the control of bulk and surface properties including the wettability, acid-base properties, adsorption, electric conductivity and capacitance. In order to gain the optimal benefit of carbon nanotubes, comprehensive understanding on manufacturing and functionalizing carbon nanotubes ought to be systematically developed. This review summarizes methodologies of manufacturing carbon nanotubes via arc discharge, laser ablation and chemical vapor deposition and functionalizing carbon nanotubes through surface oxidation and activation, doping of heteroatoms, halogenation, sulfonation, grafting, polymer coating, noncovalent functionalization and nanoparticle attachment. The characterization techniques detecting the bulk nature and surface properties as well as the effects of various functionalization approaches on modifying the surface properties for specific applications in catalysis including heterogeneous catalysis, photocatalysis, photoelectrocatalysis and electrocatalysis are highlighted.

Semiconductor-based photocatalysis and photoelectrocatalysis have received considerable attention as alternative approaches for solar energy harvesting and storage. The photocatalytic or photoelectrocatalytic performance of a semiconductor is closely related to the design of the semiconductor at the nanoscale. Among various nanostructures, one-dimensional (1D) nanostructured photocatalysts and photoelectrodes have attracted increasing interest owing to their unique optical, structural, and electronic advantages. In this article, a comprehensive review of the current research efforts towards the development of 1D semiconductor nanomaterials for heterogeneous photocatalysis and photoelectrocatalysis is provided and, in particular, a discussion of how to overcome the challenges for achieving full potential of 1D nanostructures is presented. It is anticipated that this review will afford enriched information on the rational exploration of the structural and electronic properties of 1D semiconductor nanostructures for achieving more efficient 1D nanostructure-based photocatalysts and photoelectrodes for high-efficiency solar energy conversion., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Metabolic alteration is a hallmark of cancer. Dysregulation of methionine metabolism is implicated in human liver cancer. Methionine adenosyltransferase IIα (MAT IIα) is a key enzyme in the methionine cycle, catalysing the production of S-adenosylmethionine (SAM), a key methyl donor in cellular processes, and is associated with uncontrolled cell proliferation in cancer. Here we show that P300 acetylates MAT IIα at lysine residue 81 and destabilizes MAT IIα by promoting its ubiquitylation and subsequent proteasomal degradation. Conversely, histone deacetylase-3 deacetylates and stabilizes MAT IIα by preventing its proteasomal degradation. Folate deprivation upregulates K81 acetylation and destabilizes MAT IIα to moderate cell proliferation, whereas a single mutation at K81 reverses the proliferative disadvantage of cancer cells upon folate deprivation. Moreover, MAT IIα K81 acetylation is decreased in human hepatocellular cancer. Collectively, our study reveals a novel mechanism of MAT IIα regulation by acetylation and ubiquitylation, and a direct functional link of this regulation to cancer development.

Hierarchically ordered ZnO nanorods (NRs) decorated nanoporous-layer-covered TiO2 nanotube array (ZnO NRs/NP-TNTAs) nanocomposites have been prepared by an efficient, two-step anodization route combined with an electrochemical deposition strategy, by which monodispersed one-dimensional (1D) ZnO NRs were uniformly grown on the framework of NP-TNTAs. The crystal phases, morphologies, optical properties, photocatalytic as well as photoelectrocatalytic performances of the well-defined ZnO NRs/NP-TNTAs heterostructures were systematically explored to clarify the structure-property correlation. It was found that the ZnO NRs/NP-TNTAs heterostructure exhibits significantly enhanced photocatalytic and photoelectrocatalytic performances, along with favorable photostability toward degradation of organic pollutants under UV light irradiation, as compared to the single component counterparts. The remarkably enhanced photoactivity of ZnO NRs/NP-TNTAs heterostructure is ascribed to the intimate interfacial integration between ZnO NRs and NP-TNTAs substrate imparted by the unique spatially branched hierarchical structure, thereby contributing to the efficient transfer and separation of photogenerated electron-hole charge carriers. Moreover, the specific active species during the photocatalytic process was unambiguously determined and photocatalytic mechanism was tentatively presented. It is anticipated that our work could provide new insights for the construction of various hierarchical 1D-1D hybrid nanocomposites for extensive photocatalytic applications.

In photoelectrochemical cells, there exists a competition between transport of electrons through the porous semiconductor electrode toward the conducting substrate and back-reaction of electrons to recombine with oxidized species on the semiconductor-electrolyte interface, which determines the charge collection efficiency and is strongly influenced by the density and distribution of electronic states in band gap and architectures of the semiconductor electrodes. One-dimensional (1D) anatase TiO2 nanostructures are promising to improve charge transport in photoelectrochemical devices. However, the conventional preparation of 1D anatase nanostructures usually steps via a titanic acid intermediate (e.g., H2Ti3O7), which unavoidably introduces electronic defects into the host lattice, resulting in undesired shielding of the intrinsic role of dimensionality. Here, we manage to promote the 1D growth of anatase TiO2 nanostructures by adjusting the growth kinetics, which allows us to grow single-crystalline anatase TiO2 nanorods through a one-step hydrothermal reaction. The synthesized anatase nanorods possess a lower density of trap states and thus can simultaneously facilitate the diffusion-driven charge transport and suppress the electron recombination. Moreover, the electronically boundary free nanostructures significantly enhance the trap-free charge diffusion coefficient of the anatase nanorods, which enables the emergence of the intrinsic superiority of dimensionality. By virtue of these merits, the anatase nanorods synthesized in this work take obvious advantages over the conventional anatase counterparts in photoelectrochemical systems (e.g., dye-sensitized solar cells) by showing more efficient charge transport and collection and higher energy conversion efficiency.

Sunlight is an ideal source of energy, and converting sunlight into chemical fuels, mimicking what nature does, has attracted significant attention in the past decade. In terms of solar energy conversion into chemical fuels, solar water splitting for hydrogen production is one of the most attractive renewable energy technologies, and this achievement would satisfy our increasing demand for carbon-neutral sustainable energy. Here, we report corrosion-resistant, nanocomposite photoelectrodes for spontaneous overall solar water splitting, consisting of a CdS quantum dot (QD) modified TiO2 photoanode and a CdSe QD modified NiO photocathode, where cadmium chalcogenide QDs are protected by a ZnS passivation layer and gas evolution cocatalysts. The optimized device exhibited a maximum efficiency of 0.17%, comparable to that of natural photosynthesis with excellent photostability under visible light illumination. Our device shows spontaneous overall water splitting in a nonsacrificial environment under visible light illumination (λ > 400 nm) through mimicking nature's "Z-scheme" process. The results here also provide a conceptual layout to improve the efficiency of solar-to-fuel conversion, which is solely based on facile, scalable solution-phase techniques.

Purpose: The aim of this study was to optimize reverse iontophoretic (RI) extraction of ferric/ferrous ions from the cornea., Methods: Group I consisted of the right eye corneas from 20 normal rabbits. Corneal blood staining was induced in 60 right eyes. The corneal depths from the endothelium to the epithelium layers were divided into three groups by slit-lamp examination: Group II, one-third corneal thickness; Group III, one-half corneal thickness; Group IV, full corneal thickness. RI was performed using vertical diffusion cells. The lower chamber was loaded with glutathione bicarbonate Ringer's buffer (GBR; pH 7.0) or vitamin C (12.5 mg/mL) and GBR (pH 7.0), while the upper chamber was filled with 1 mL GBR. Progress of corneal blood staining removal was evaluated., Results: Application of 1.5 mA to the cornea increased flux by 1.72- and 2.19-fold in Groups III and IV, respectively, but not in Groups I or II, compared to the control. When vitamin C was included, we observed significant flux increases in the controls (1.5-, 2.06-, 2.60-, and 4.59-fold) for Groups I, II, III, and IV, and under RI conditions for Groups III and IV. Following RI, the corneal endothelia appeared similar to corneas from untreated control rabbits, while Draize scores were zero., Conclusions: These results suggested that extracellular ferric/ferrous ions could be extracted from the cornea in vitro by RI, and that vitamin C reduced Fe(3+) to Fe(2+) in the cornea and altered its permselectivity, thus increasing the RI contribution to iron extraction.

A biomolecule-assisted pyrolysis method has been developed to synthesize sulfur-doped graphitic carbon nitride (CNS) nanosheets. During the synthesis, sulfur could be introduced as a dopant into the lattice of carbon nitride (CN). Sulfur doping changed the texture as well as relative band positions of CN. By growing CN on preformed sulfur-doped CN nanosheets, composite CN/CNS heterojunction nanosheets were constructed, which significantly enhanced the photoelectrochemical performance as compared with various control counterparts including CN, CNS and physically mixed CN and CNS (CN+CNS). The enhanced photoelectrochemical performance of CN/CNS heterojunction nanosheets could be ascribed to the efficient separation of photoexcited charge carriers across the heterojunction interface. The strategy of designing and preparing CN/CNS heterojunction photocatalysts in this work can open up new directions for the construction of all CN-based heterojunction photocatalysts.

Solution processable inverted bulk heterojunction (BHJ) polymer solar cells (PSCs) are promising alternatives to conventional silicon solar cells because of their low cost roll-to-roll production and flexible device applications. In this work, we demonstrated that Cs2CO3 functionalized graphene quantum dots (GQDs-Cs2CO3) could be used as efficient electron-selective layers in inverted PSCs. Compared with Cs2CO3 buffered devices, the GQDs-Cs2CO3 buffered devices show 56% improvement in power conversion efficiency, as well as 200% enhancement in stability, due to the better electron-extraction, suppression of leakage current, and inhibition of Cs(+) ion diffusion at the buffer/polymer interface by GQDs-Cs2CO3. This work provides a thermal-annealing-free, solution-processable method for fabricating electron-selective layer in inverted PSCs, which should be beneficial for the future development of high performance all-solution-processed or roll-to-roll processed PSCs.

Efficient hydrogen production from photoelectrochemical (PEC) water splitting is a promising route to solve the approaching energy crisis. Herein, we report a facile all-electrochemical approach to fabricate well-aligned ZnO-CdSe core-shell nanorod arrays with excellent uniformity on transparent indium tin oxide (ITO) substrates. The shell thickness of the core-shell nanorods can be tuned precisely by adjusting the charge density passing through the working electrode during the deposition of CdSe quantum dots (QDs). The optimized ZnO-CdSe nanorod arrays showed excellent PEC performance with a significant saturated photocurrent density of 14.9 mA cm(-2) at 0.8 V (vs. RHE) under AM 1.5 illumination, which is, to the best of our knowledge, the highest value ever reported for similar nanostructures, owing to the favourable band alignment and good distribution of CdSe QDs on ZnO nanorods. Our results demonstrate that the electrochemically deposited ZnO-CdSe nanorod arrays can be utilized as efficient photoanodes in PEC water splitting cells.