Photoelectrocatalytic Synthesis of Urea from Carbon Dioxide and Nitrate over a Cu2O Photocathode.

Transformation of carbon dioxide and nitrate ions into urea offers an attractive route for both nitrogen fertilizer production and environmental remediation. However, achieving this transformation under mild conditions remains challenging. Herein, we report an efficient photoelectrochemical method for urea synthesis by co-reduction of carbon dioxide and nitrate ion over a Cu2O photocathode, delivering urea formation rate of 29.71±2.20 µmol g-1 h-1 and Faradaic efficiency (FE) of 12.90±1.15 % at low external potential (-0.017 V vs. reversible hydrogen electrode). Experimental data combined with theoretical calculations suggest that the adsorbed CO* and NO2* species are the key intermediates, and associated C-N coupling is the rate-determining step. This work demonstrates that Cu2O is an efficient catalyst to drive co-reduction of CO2 and NO3 - to urea under light irradiation with low external potential, showing great opportunity of photoelectrocatalysis as a sustainable tool for value-added chemical synthesis.

Electrocatalytic Upcycling of Biomass and Plastic Wastes to Biodegradable Polymer Monomers and Hydrogen Fuel at High Current Densities.

Transformation of biomass and plastic wastes to value-added chemicals and fuels is considered an upcycling process that is beneficial to resource utilization. Electrocatalysis offers a sustainable approach; however, it remains a huge challenge to increase the current density and deliver market-demanded chemicals with high selectivity. Herein, we demonstrate an electrocatalytic strategy for upcycling glycerol (from biodiesel byproduct) to lactic acid and ethylene glycol (from polyethylene terephthalate waste) to glycolic acid, with both products being as valuable monomers for biodegradable polymer production. By using a nickel hydroxide-supported gold electrocatalyst (Au/Ni(OH)2), we achieve high selectivities of lactic acid and glycolic acid (77 and 91%, respectively) with high current densities at moderate potentials (317.7 mA/cm2 at 0.95 V vs RHE and 326.2 mA/cm2 at 1.15 V vs RHE, respectively). We reveal that glycerol and ethylene glycol can be enriched at the Au/Ni(OH)2 interface through their adjacent hydroxyl groups, substantially increasing local concentrations and thus high current densities. As a proof of concept, we employed a membrane-free flow electrolyzer for upcycling triglyceride and PET bottles, attaining 11.2 g of lactic acid coupled with 9.3 L of H2 and 13.7 g of glycolic acid coupled with 9.4 L of H2, respectively, revealing the potential of coproduction of valuable chemicals and H2 fuel from wastes in a sustainable fashion.

Identification of Active Sites Formed on Cobalt Oxyhydroxide in Glucose Electrooxidation.

Transition-metal-based oxyhydroxides are efficient catalysts in biomass electrooxidation towards fossil-fuel-free production of valuable chemicals. However, identification of active sites remains elusive. Herein, using cobalt oxyhydroxide (CoOOH) as the archetype and the electrocatalyzed glucose oxidation reaction (GOR) as the model reaction, we track dynamic transformation of the electronic and atomic structure of the catalyst using a suite of operando and ex situ techniques. We reveal that two types of reducible Co3+ -oxo species are afforded for the GOR, including adsorbed hydroxyl on Co3+ ion (µ1 -OH-Co3+ ) and di-Co3+ -bridged lattice oxygen (µ2 -O-Co3+ ). Moreover, theoretical calculations unveil that µ1 -OH-Co3+ is responsible for oxygenation, while µ2 -O-Co3+ mainly contributes to dehydrogenation, both as key oxidative steps in glucose-to-formate transformation. This work provides a framework for mechanistic understanding of the complex near-surface chemistry of metal oxyhydroxides in biomass electrorefining.

Selective Photoelectrocatalytic Glycerol Oxidation to Dihydroxyacetone via Enhanced Middle Hydroxyl Adsorption over a Bi2O3-Incorporated Catalyst.

Photoelectrocatalytic (PEC) glycerol oxidation offers a sustainable approach to produce dihydroxyacetone (DHA) as a valuable chemical, which can find use in cosmetic, pharmaceutical industries, etc. However, it still suffers from the low selectivity (≤60%) that substantially limits the application. Here, we report the PEC oxidation of glycerol to DHA with a selectivity of 75.4% over a heterogeneous photoanode of Bi2O3 nanoparticles on TiO2 nanorod arrays (Bi2O3/TiO2). The selectivity of DHA can be maintained at ∼65% under a relatively high conversion of glycerol (∼50%). The existing p-n junction between Bi2O3 and TiO2 promotes charge transfer and thus guarantees high photocurrent density. Experimental combined with theoretical studies reveal that Bi2O3 prefers to interact with the middle hydroxyl of glycerol that facilitates the selective oxidation of glycerol to DHA. Comprehensive reaction mechanism studies suggest that the reaction follows two parallel pathways, including electrophilic OH* (major) and lattice oxygen (minor) oxidations. Finally, we designed a self-powered PEC system, achieving a DHA productivity of 1.04 mg cm-2 h-1 with >70% selectivity and a H2 productivity of 0.32 mL cm-2 h-1. This work may shed light on the potential of PEC strategy for biomass valorization toward value-added products via PEC anode surface engineering.

[Scoping review of domestic and overseas hospital-based health technology assessment].

This paper systematically sorted out the related research on hospital-based health technology assessment(HB-HTA) and clarified the research status of this field to provide a basis for the future research direction and focus of HTA in traditional Chinese medicine(TCM) hospitals. Based on the scoping review, relevant research papers were retrieved from Chinese databases(including CNKI, Wanfang, VIP, and SinoMed) and PubMed and analyzed. Among the included 99 papers, the earliest one was published in 2005 in China, and the number of papers has been increasing since 2016. In terms of journals, the included papers were published in 39 journals, including 24 core ones and 2 SCI ones. In terms of the number of publications, the Chinese Journal of Evidence-Based Medicine accounted for the majority(n=6). Among the 175 authors involved, three of them published 15 papers, respectively, accounting for 20.83% and ranking the top, and they came from Renmin University of China and the National Health Commission of China. There were 38 first units dominated by hospitals. Hebei General Hospital published the most papers(n=10), followed by Renmin University of China(n=9) and the National Health Commission of China(n=7). In terms of research type, the research papers were dominated by evaluation and practice ones(n=29), followed by reviews(n=20). In terms of research topic, the research was mainly carried out from devices(n=26) and macro-perspective scope(n=24). Half of the research in China was funded. For 27 research papers published abroad, the number of publications in the past five years was small, with 16 countries involved. Developed countries paid more attention to this field than developing countries. Especially in Europe and the US, the publishing institutions were mainly universities, and the types of research were mainly interviews and evaluation or practice. In recent years, the attention of HB-HTA in China has been increasing year by year, and the development of related projects has provided a scientific decision-making basis for the admission and management of new technologies in hospitals in China. However, there are few researchers and institutions in this field, and the research scope is small. In the future, more investment is needed to encourage more hospitals, especially TCM hospitals, to carry out HB-HTA, explore the HB-HTA system suitable for Chinese conditions, and improve the scientific decision-making of hospitals.

[Scoping review of clinical evidence of Chinese patent medicines for digestive system diseases in children].

This study analyzed and reported the basic information and clinical evidence of Chinese patent medicines for digestive system diseases in children in a scoping review manner. Based on the drug instructions, the basic information of Chinese patent medicines for digestive system diseases in children was obtained by searching the three lists of national medicines. At the same time, the relevant clinical literatures from the first day of establishment to March 7, 2022 were obtained from Chinese and English databases. According to the screening criteria, 39 Chinese patent medicines were included, involving 8 dosage forms. Eight Chinese medicines including Crataegi Fructus, Poria, Citri Reticulatae Pericarpium, Hordei Fructus Germinatus, Arecae Semen, Massa Medicata Fermentata, Dioscoreae Rhizoma, and Atractylodis Macrocephalae Rhizoma were frequently used, and the main effects were invigorating spleen, checking diarrhea, promoting digestion, clearing heat, and harmonizing stomach. The indications for Chinese patent medicines were mainly diarrhea, anorexia, food accumulation, dyspepsia, and rotavirus enteritis in children. Among all drug instructions, only 4 mentioned adverse reactions and 6 mentioned contraindications. Ninety-two clinical studies were included ultimately, including 84 randomized controlled studies, 2 systematic reviews/Meta-analysis, 1 retrospective study, and 5 case series. The literatures only covered 21 kinds of Chinese patent medicines, with the most studies related to Xingpi Yanger Granules, accounting for 32.6% of the total literature volume. The sample size in the literatures was mainly focused on 51-200 cases, and 51-100 cases were selected by the most literatures, accounting for 34.45%. The interventions of the experimental group were mainly Chinese patent medicines or Chinese patent medicines combined with western medicines. The literatures with treatment course of 0-7 d accounted for the largest proportion(51.10%). The effective rate and symptom improvement time were used as the indexes to evaluate the results. The main adverse reactions were vomiting, constipation, nausea, rash, cold, diarrhea, redness of the skin around the umbilicus, or red itchy skin. The analysis of this study found that Chinese patent medicines have good curative effect and research prospects in the treatment of digestive system diseases in children. However, most clinical evidence has problems, such as limited indexes to evaluate the results, lack of traditional Chinese medicine characteristics, uneven quantity and low quality of Chinese patent medicine literatures, and insufficient specification of instructions. In the future, high-quality clinical studies on this field should be actively carried out, and economic studies and clinical comprehensive evaluation of Chinese patent medicines should be strengthened to explore the characteristics and advantages of its treatment, so as to provide decision-making basis for finding the accurate clinical positioning and promoting the rational clinical application of Chinese patent medicines for treating digestive system diseases in children.

[Four Chinese patent medicines for regulating stomach for functional dyspepsia: a rapid health technology assessment].

This study evaluated and compared the efficacy, safety and economy of four Chinese patent medicines(CPMs) in the treatment of functional dyspepsia(FD) using the method of rapid health technology assessment. It aims to provide decision-makers with rapid decision-making information. The eight Chinese and English databases were comprehensively and systematically searched for the relevant clinical research. Studies were screened and evaluated. A total of 110 studies were identified, including 95 randomized controlled trials(RCTs), 7 controlled clinical trials(CCTs), 7 systematic review/Meta-analysis and 1 economic evaluation, among which 28 were Dalitong Granules, 49 were Zhizhu Kuanzhong Capsules, 3 were Biling Weitong Granules and 30 were Qizhi Weitong Granules(Tablets/Capsules). The quality of the included literature was generally low. The efficacy of four CPMs alone or combined with western medicine in the treatment of FD is different. Dalitong Granules was used to treat motility disorder in FD. Zhizhu Kuanzhong Capsules and Qizhi Weitong Granules(Tablets/Capsules) can treat FD patients with anxiety and depression. Qizhi Weitong Granules(Tablets/Capsules) were mainly used in FD for perimenopausal patients. There were no serious adverse reactions in the clinical study of four CPMs in the treatment of FD. Dalitong Granules has better effects than mosapride in the treatment of FD, but the cost is slightly higher. The cost-effectiveness ratio of Zhizhu Kuanzhong Capsules in the treatment of FD patients with anxiety and depression was lower than that of Domperidone. In terms of average daily price, Qizhi Weitong Tablets has the highest price(27.00 yuan per day), Qizhi Weitong Granules has the lowest price(5.04 yuan per day), Biling Weitong Granules has a relatively high price(15.53 yuan per day), followed by Dalitong Granules(13.03 yuan per day). The evidence of Dalitong Granules covered the efficacy, safety and economy, which is relatively complete compared with the other three drugs. It has effective potential in the treatment of motility disorder in FD. Further research in this field in the future is needed.

[Scoping review of rapid health technology assessment].

This study aims to summarize the research on rapid health technology assessment(RHTA) based on scoping review, which is expected to serve as a reference for future research on RHTA. First, articles on RHTA were retrieved from both Chinese and English databases. After data screening and extraction by two personnel independently, descriptive analysis was conducted on the results, and evidence distribution was analyzed based on tables, bar charts, line charts, radar charts, and pie charts. Finally, a total of 82 eligible articles were included and the characteristics were as follows.(1) Articles on RHTA were mainly published from 2011 to 2022. The number of articles showed an obvious increase from 2014 and surged in 2019.(2) Among the journals with the above RHTA papers published, Chinese Journal of New Drugs(21.5%), Evaluation and Analysis of Drug-Use in Hospitals of China(16.9%), and Chinese Pharmacy(15.4%) topped the Chinese journals in the number of the papers, while International Journal of Technology Assessment in Health Care(23.5%), Reviews in Medical Virology(11.8%), and Value in Health(11.8%) came out on top in the English journals.(3)The RHTA of drugs(especially western medicine)(68.7%) dominated the eligible articles, followed by the RHTA of therapy technology(13.1%), detection technology(5.1%), and diagnosis technology(1.0%). There was a significant gap in the number of studies among different health technology categories and an imbalance in the types of health technologies involved in the overall RHTA studies.(4) RHTA of tumors has been the research focus in recent years. In summary, RHTA plays a positive role in rapid health decision-making, but there is a lack of primary data sources at present. Compared with the systematic review, Meta-analysis, and pharmacoeconomic studies, a few reports on health technology assessment(HTA) were included. In the future, research on the evaluation of the safety, efficacy, cost effectiveness and social applicability of health technologies should be further strengthened.

[Multi-criteria decision analysis in clinical comprehensive evaluation of Chinese patent medicine].

Multi-criteria decision analysis(MCDA), a comprehensive analysis method that can help decision-makers consider multiple criteria systematically, has been used for clinical comprehensive evaluation of drugs, such as chemicals and Chinese patent medicines. The present study summarized the theoretical basis of MCDA and its application in the clinical comprehensive evaluation of drugs and put forward suggestions. MCDA includes problem identification, structuring problem, model building, and using the model to inform and challenge thinking to develop an action plan. The modeling methods include value measurement models, outranking models, and reference-level models. The value measurement model is the most commonly used method in healthcare. The implementation steps of MCDA consist of defining the decision problem, selecting and structuring criteria, measuring performance, scoring alternatives, weighting criteria, calculating aggregate scores, dealing with uncertainty, and reporting and examination of findings. It is urgent to carry out the clinical comprehensive evaluation of Chinese patent medicine, the important part of traditional Chinese medicine(TCM), to promote its scientization, homogenization, and standardization. It is of great significance to carry out the clinical comprehensive evaluation of Chinese patent medicine with MCDA, which should be demand-oriented, coordinated by many parties, and learn from international experience and successful practice to establish the corresponding technical guidelines, specifications, and evaluation tools, so as to provide technical support for Chinese patent medicine supply and policy formulation.

[Enlightenment of WHO guideline on institutionalizing health technology assessment mechanism for traditional Chinese medicine].

To promote the institutionalization of the health technology assessment(HTA) mechanism in various countries, World Health Organization(WHO) has published the Institutionalizing Health Technology Assessment Mechanisms: a How to Guide to introduce five steps of institutionalizing the HTA mechanism systematically, specifically, "establishing a mandate; establishing the legal framework; reviewing or establishing the legal framework; establishing institutional and governance arrangements; processes and evidence required for assessment and appraisal; and monitoring and evaluation". Traditional Chinese medicine(TCM) HTA can provide scientific information and decision-making evidence for decision-makers at all levels to select TCM health technology reasonably, and promote the high-quality development of the TCM healthcare system. However, TCM HTA is in its infancy, and it is imperative to carry out relevant work under the guidance of global standard documents to ensure standardization, transparency, and fairness. In light of the WHO guidance, this research group put forward the necessity and logical framework for the institutionalizing HTA mechanism of TCM, which is helpful to establish the institutionalizing HTA mechanism in line with national conditions and suitable for TCM, provide scientific guidance for the research of TCM HTA, and contribute to TCM healthcare decision-making.

[Rapid health technology assessment of four oral Chinese patent medicines for constipation].

This study evaluated the safety, efficacy, and cost effectiveness of Biantong Capsules(Tablets), Maren Runchang Pills, Qirong Runchang Oral Liquid, and Qihuang Tongmi Soft Capsules in the treatment of constipation by the rapid health technology assessment(RHTA) to provide evidence for clinical decision and references for rapid evaluation of Chinese patent medicine(CPM). CNKI, Wanfang, VIP, SinoMed, PubMed, EMbase, Web of Science, and Cochrane Library were searched for research articles from database inception to February 2022. Two reviewers conducted literature screening, data extraction, and quality evaluation according to the predetermined standards. Descriptive analysis of the results combined with visual charts was performed. Sixty research articles were included, involving 44 randomized controlled trials(RCTs), 7 clinical controlled trials(CCTs), 4 systematic reviews/Meta-analyses, and 5 economic analysis studies. As revealed by the results, Biantong Capsules(Tablets) could be used for postoperative and senile constipation, in which some studies reported Biantong Capsules(Tablets) were superior to Maren Runchang Pills and Qirong Runchang Oral Liquid. Maren Runchang Pills were mainly used for senile constipation, and the efficacy was similar to that of conventional wes-tern medicine, but the cost was low and the compliance of patients was good. Qirong Runchang Oral Liquid was indicated for disease-derived or drug-induced constipation, chronic constipation, and senile constipation with fewer adverse reactions. Qihuang Tongmi Soft Capsules had good efficacy and safety in the treatment of functional constipation. Overall, compared with western medicine glycerine enema and lactulose, the number of clinical studies of the four CMPs was small, but they targeted constipation patients with different subtypes. In conclusion, the four CMPs have their advantages and characteristics in the treatment of constipation, but they are restric-ted by sparse existing evidence, low quality of evidence, and insufficient economic research. In the future, more high-quality and long-term follow-up studies should be carried out to obtain reliable evidence. Meanwhile, it is called for strengthening the economic evaluation of CMPs to provide evidence for decision-making.

Electrocatalytic Hydrogenation of 5-Hydroxymethylfurfural Promoted by a Ru1 Cu Single-Atom Alloy Catalyst.

Electrochemical reduction of biomass-derived 5-hydroxymethylfurfural (HMF) represents an elegant route toward sustainable value-added chemicals production that circumvents the use of fossil fuel and hydrogen. However, the reaction efficiency is hampered by the high voltage and low activity of electrodes (Cu, Bi, Pb). Herein, we report a Ru1 Cu single-atom alloy (SAA) catalyst with isolated Ru atoms on Cu nanowires that exhibits an electrochemical reduction of HMF to 2,5-dihydroxymethylfuran (DHMF) with promoted productivity (0.47 vs. 0.08 mmol cm-2 h-1 ) and faradic efficiency (FE) (85.6 vs. 71.3 %) at -0.3 V (vs. RHE) compared with Cu counterpart. More importantly, the FE (87.5 %) is largely retained at high HMF concentration (100 mM). Kinetic studies by using combined electrochemical techniques suggest disparate mechanisms over Ru1 Cu and Cu, revealing that single-atom Ru promotes the dissociation of water to produce H* species that effectively react with HMF via an electrocatalytic hydrogenation (ECH) mechanism.

Selective Electrooxidation of Biomass-Derived Alcohols to Aldehydes in a Neutral Medium: Promoted Water Dissociation over a Nickel-Oxide-Supported Ruthenium Single-Atom Catalyst.

The biomass-derived alcohol oxidation reaction (BDAOR) holds great promise for sustainable production of chemicals. However, selective electrooxidation of alcohols to value-added aldehyde compounds is still challenging. Herein, we report the electrocatalytic BDAORs to selectively produce aldehydes using single-atom ruthenium on nickel oxide (Ru1 -NiO) as a catalyst in the neutral medium. For electrooxidation of 5-hydroxymethylfurfural (HMF), Ru1 -NiO exhibits a low potential of 1.283 V at 10 mA cm-2 , and an optimal 2,5-diformylfuran (DFF) selectivity of 90 %. Experimental studies reveal that the neutral electrolyte plays a critical role in achieving a high aldehyde selectivity, and the single-atom Ru boosts HMF oxidation in the neutral medium by promoting water dissociation to afford OH*. Furthermore, Ru1 -NiO can be extended to selective electrooxidation of a series of biomass-derived alcohols to corresponding aldehydes, which are conventionally difficult to obtain in the alkaline medium.

Selectively Upgrading Lignin Derivatives to Carboxylates through Electrochemical Oxidative C(OH)-C Bond Cleavage by a Mn-Doped Cobalt Oxyhydroxide Catalyst.

Oxidative cleavage of C(OH)-C bonds to afford carboxylates is of significant importance for the petrochemical industry and biomass valorization. Here we report an efficient electrochemical strategy for the selective upgrading of lignin derivatives to carboxylates by a manganese-doped cobalt oxyhydroxide (MnCoOOH) catalyst. A wide range of lignin-derived substrates with C(OH)-C or C(O)-C units undergo efficient cleavage to corresponding carboxylates in excellent yields (80-99 %) and operational stability (200 h). Detailed investigations reveal a tandem oxidation mechanism that base from the electrolyte converts secondary alcohols and their derived ketones to reactive nucleophiles, which are oxidized by electrophilic oxygen species on MnCoOOH from water. As proof of concept, this approach was applied to upgrade lignin derivatives with C(OH)-C or C(O)-C motifs, achieving convergent transformation of lignin-derived mixtures to benzoate and KA oil to adipate with 91.5 % and 64.2 % yields, respectively.

Anion exchange behavior of MIIAl layered double hydroxides: a molecular dynamics and DFT study.

The ion exchange reaction has been extensively used in the field of synthesis of functionalized supramolecular materials such as layered double hydroxides (LDHs), ion-embedded batteries, sewage disposal and so on. In this work, the factors influencing the anion exchange behavior in the LDH gallery, such as the exchange domain, the exchange order, the driving force, and the diffusion of the anions, are investigated systematically using molecular dynamics (MD) simulations and density functional theory (DFT) methods in view of both thermodynamics and dynamics. 159 models of MIIRAl-A-LDHs (MII = Mg, Ni, Zn; R = 1.4-8, A = OH-, Cl-, Br-, NO3-, HCOO-, C6H5SO3-, CO32-, SO42-, and PO43-, respectively) are calculated. The results reveal that the anion exchange domain (interlayer distance) in LDHs is determined not only by the size and their arrangement modes of the guest anions, but also by the charges the anions carry. The relative binding energies of different anions and the Gibbs free energy changes of the anion exchange reactions in LDHs decrease in the order of PO43- > CO32- > SO42- > OH- > Cl- > Br- > HCOO- > NO3- > C6H5SO3-, which is in accordance with the experimental anion exchange order. The stronger the hydrogen bonding between the anion and the host, the larger the charge transfer, and the smaller the electronegativity of the anion, the more difficult it is for the anion to be exchanged out from LDH interlayer. In addition, for the anions with the same charges, the relative binding energy is linearly well correlated with the interlayer spacing. By analyzing the contribution of each energetic item comprising the total potential energy, it is found that the major driving force of anion exchange is the electrostatic force. The diffusion coefficient (D) along the c direction is nearly equal to zero, suggesting that the diffusion of anions occurs mainly in the ab plane of the LDH cell. It also can be inferred that when the cell parameter c < 24.0 Å, the anion exchange order is mainly determined by the thermodynamic factors, whereas when c > 24.0 Å, both the thermodynamic and the dynamic factors cast the same effect on the anion exchange behavior. This work provides an in-depth understanding of the anion exchange behavior, and is helpful guidance for the design and synthesis of functionalized guest anion intercalated LDHs and related materials using the anion-exchange method.

Highly Selective Photoreduction of CO2 with Suppressing H2 Evolution over Monolayer Layered Double Hydroxide under Irradiation above 600†nm.

Although progress has been made to improve photocatalytic CO2 reduction under visible light (λ>400 nm), the development of photocatalysts that can work under a longer wavelength (λ>600 nm) remains a challenge. Now, a heterogeneous photocatalyst system consisting of a ruthenium complex and a monolayer nickel-alumina layered double hydroxide (NiAl-LDH), which act as light-harvesting and catalytic units for selective photoreduction of CO2 and H2 O into CH4 and CO under irradiation with λ>400 nm. By precisely tuning the irradiation wavelength, the selectivity of CH4 can be improved to 70.3 %, and the H2 evolution reaction can be completely suppressed under irradiation with λ>600 nm. The photogenerated electrons matching the energy levels of photosensitizer and m-NiAl-LDH only localized at the defect state, providing a driving force of 0.313 eV to overcome the Gibbs free energy barrier of CO2 reduction to CH4 (0.127 eV), rather than that for H2 evolution (0.425 eV).

Cobalt Phosphide Composite Encapsulated within N,P-Doped Carbon Nanotubes for Synergistic Oxygen Evolution.

Exploring highly efficient and stable oxygen evolution reaction (OER) electrocatalysts such as transition-metal phosphides (TMPs) is critical to advancing renewable hydrogen fuel. TMP nanostructures typically involving binary or ternary TMPs tuned by cation or anion doping are suggested to be promising low-cost and durable OER catalysts. Herein, the preparation of CoP/CoP2 composite nanoparticles encapsulated within N,P-doped carbon nanotubes (CoP/CoP2 @NPCNTs) is demonstrated as a synergistic electrocatalyst for OER via the calcination of a CoAl-layered double hydroxide/melamine mixture and subsequent phosphorization. Facile visualization by scanning electron microscopy in conjunction with electron backscatter diffraction demonstrates the encapsulation of the CoP/CoP2 nanoparticles within the N,P-codoped CNTs. Electrocatalytic evaluation shows that the composite electrode requires a low overpotential of 300 mV for the OER at 10 mA cm-2 in a 1.0 m KOH solution and, in particular, exhibits an excellent long-term durability of ≈100 h, which is superior to that of the state-of-the-art RuO2 electrocatalyst. Density functional theory calculations reveal that the synergistic effect of CoP and CoP2 can enhance the electrocatalytic performance. In addition, molecular dynamics simulations demonstrate that the generated O2 molecules can readily diffuse out of the CNTs. Both the effects give rise to the observed OER enhancement.

Engineering Spin Polarization of the Surface-Adsorbed Fe Atom by Intercalating a Transition Metal Atom into the MoS2 Bilayer for Enhanced Nitrogen Reduction.

The precise control of spin states in transition metal (TM)-based single-atom catalysts (SACs) is crucial for advancing the functionality of electrocatalysts, yet it presents significant scientific challenges. Using density functional theory (DFT) calculations, we propose a novel mechanism to precisely modulate the spin state of the surface-adsorbed Fe atom on the MoS2 bilayer. This is achieved by strategically intercalating a TM atom into the interlayer space of the MoS2 bilayer. Our results show that these strategically intercalated TM atoms can induce a substantial interfacial charge polarization, thereby effectively controlling the charge transfer and spin polarization on the surface Fe site. In particular, by varying the identity of the intercalated TM atoms and their vacancy filling site, a continuous modulation of the spin states of the surface Fe site from low to medium to high can be achieved, which can be accurately described using descriptors composed of readily accessible intrinsic properties of materials. Using the electrochemical dinitrogen reduction reaction (eNRR) as a prototypical reaction, we discovered a universal volcano-like relation between the tuned spin and the catalytic activity of Fe-based SACs. This finding contrasts with the linear scaling relationships commonly seen in traditional studies and offers a robust new approach to modulating the activity of SACs through interfacial engineering.

Interplay between Defects and Short-Range Disorder Manipulating the Oxygen Evolution Reaction on a Layered Double Hydroxide Electrocatalyst.

Improving the efficiency of the oxygen evolution reaction (OER) is crucial for advancing sustainable and environmentally friendly hydrogen energy. Layered double hydroxides (LDHs) have emerged as promising electrocatalysts for the OER. However, a thorough understanding of the impact of structural disorder and defects on the catalytic activity of LDHs remains limited. In this work, a series of NiAl-LDH models are systematically constructed, and their OER performance is rigorously screened through theoretical density functional theory. The acquired results unequivocally reveal that the energy increase induced by structural disorder is effectively counteracted at the defect surface, indicating the coexistence of defects and disorder. Notably, it is ascertained that the simultaneous presence of defects and disorder synergistically augments the catalytic activity of LDHs in the context of the OER. These theoretical findings offer valuable insights into the design of highly efficient OER catalysts while also shedding light on the efficacy of LDH electrocatalysts.

Upregulation of glutamate transporter GLT-1 by mTOR-Akt-NF-кB cascade in astrocytic oxygen-glucose deprivation.

Excessive extracellular glutamate leads to neuronal death in central nervous system. Excitatory glutamate transporter subtype 2 (GLT-1) carries bulk of glutamate reuptake in cerebral ischemia. Although GLT-1 expression fluctuates during the period of ischemia, little is known about its regulatory mechanism. Here we show an up-regulation of GLT-1 via mammalian target of rapamycin (mTOR)-Akt-nuclear factor-кB (NF-кB) signaling cascade in oxygen glucose deprivation (OGD). We found that brief rapamycin treatment significantly increased GLT-1 expression in cultured astrocytes. Rapamycin increased phosphorylation of raptor at Ser792 and decreased phosphorylation of rictor at Thr1135, suggesting that both mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2) are involved in GLT-1 expression. This conclusion was further confirmed by raptor and rictor disruption experiments. Akt was activated by mTORC1 inhibition and required for GLT-1 expression because triciribine, a specific inhibitor of Akt, blocked the increase of GLT-1 expression. mTOR-Akt cascade then activated NF-кB and increased кB-motif-binding phosphoprotein (KBBP) expression and GLT-1 transcription. We next demonstrated that mTOR-Akt-NF-кB cascade was activated in OGD and subsequently caused the upregulation of GLT-1. Supporting evidence included: (1) inhibition of Akt or NF-кB occluded OGD-induced GLT-1 upregulation; (2) Raptor knock-down plus OGD did not add to the increase of GLT-1 expression; (3) Intact mTORC2 was required for GLT-1 enhancement. In summary, our data first showed that mTOR-Akt-NF-кB cascade played critical roles to up-regulate GLT-1 in OGD. This signaling cascade may work to promote glutamate uptake in brain ischemia and neurodegenerative diseases.