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1.
Discov Nano ; 19(1): 162, 2024 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-39356392

RESUMO

Under the dual pressures of environmental protection and energy security, the development and application of coal-based nanocarbon materials, supported by the technical concepts of molecular chemical engineering and nanomaterial science, is of significant importance for achieving the high-value clean utilization of coal. Furthermore, it serves as an effective means to assist in the realization of dual carbon goals. Coal, with its abundant reserves, high carbon content, and aromatic and hydrogenated aromatic groups, exhibits great advantages and potential in the synthesis of nanocarbon materials. In addition to its applications in traditional power and chemical industries, coal-based nanocarbon materials also demonstrate significant value in the field of environmental pollution control. This article succinctly summarizes the preparation methods and properties of coal-based carbon nanotubes, coal-based carbon quantum dots, and coal-based graphene, elucidates their current applications in water pollution control and governance, and anticipates their development trends in water pollution control, aiming to provide support for the clean and efficient utilization of coal and water pollution control.

2.
RSC Adv ; 14(41): 30070, 2024 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-39309644

RESUMO

[This corrects the article DOI: 10.1039/D4RA03407D.].

3.
RSC Adv ; 14(37): 27298-27309, 2024 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-39193278

RESUMO

Carbon dioxide (CO2) is a prominent greenhouse gas and a widely available carbon resource. The chemical conversion of CO2 into high-value chemicals and fuels is a significant approach for mitigating carbon emissions and attaining carbon neutrality. However, enhancing CO2 adsorption and conversion rates remains a primary challenge in CO2 recycling. The development of high-performance catalysts is pivotal for the catalytic conversion of CO2. In this context, coal-based carbon materials, characterized by their extensive specific surface area and adaptable chemical composition, can offer more reactive active sites and have robust CO2 adsorption capabilities. They can function as either standalone catalysts or as components of composite catalysts, making them promising materials for CO2 reduction. The use of affordable and abundant coal as a precursor for carbon materials represents a crucial avenue for achieving clean and efficient coal utilization. This paper reviews the progress of research on coal-based carbon materials and examines their advantages and challenges as catalysts for CO2 reduction.

4.
World J Gastrointest Endosc ; 16(8): 483-488, 2024 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-39155996

RESUMO

BACKGROUND: Multisystem inflammatory syndrome in adults (MIS-A) is a rare but severe disease occurring several weeks after severe acute respiratory syndrome coronavirus 2 infection. It develops in adults with inflammation of different organs including the gastrointestinal tract, heart, kidneys, skin and hematopoietic system. CASE SUMMARY: We present a 58-year-old Chinese man diagnosed with MIS-A. His chief complaints were fever, generalized fatigue and anorexia, accompanied with rashes on his back. Further examination showed cardiac, renal and liver injury. He had melena and gastroscopy indicated esophageal ulcer and severe esophagitis. Repeated blood and sputum culture did not show growth of bacteria or fungi. Antibiotic treatment was stopped due to unsatisfactory performance. His condition improved after prednisone and other supportive treatment. CONCLUSION: Gastrointestinal involvement in MIS-A is not uncommon. Intestinal involvement predominates, and esophageal involvement is rarely reported. Esophageal ulcer with bleeding could also be a manifestation of MIS-A.

5.
Front Pharmacol ; 15: 1465697, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39193338

RESUMO

Mesenchymal stem cells (MSCs) are a type of pluripotent adult stem cell with strong self-renewal and multi-differentiation abilities. Their excellent biological traits, minimal immunogenicity, and abundant availability have made them the perfect seed cells for treating a wide range of diseases. After more than 60 years of clinical practice, metformin is currently one of the most commonly used hypoglycaemic drugs for type 2 diabetes in clinical practice. In addition, metformin has shown great potential in the treatment of various systemic diseases except for type 2 diabetes in recent years, and the mechanisms are involved with antioxidant stress, anti-inflammatory, and induced autophagy, etc. This article reviews the effects and the underlying mechanisms of metformin on the biological properties, including proliferation, multi-differentiation, and aging, of MSCs in vitro and in vivo with the aim of providing theoretical support for in-depth scientific research and clinical applications in MSCs-mediated disease treatment.

6.
Gut Microbes ; 16(1): 2377576, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39068517

RESUMO

The global incidence and prevalence of inflammatory bowel disease (IBD) are gradually increasing. A high-fat diet (HFD) is known to disrupt intestinal homeostasis and aggravate IBD, yet the underlying mechanisms remain largely undefined. Here, a positive correlation between dietary fat intake and disease severity in both IBD patients and murine colitis models is observed. A HFD induces a significant decrease in indole-3-acetic acid (IAA) and leads to intestinal barrier damage. Furthermore, IAA supplementation enhances intestinal mucin sulfation and effectively alleviates colitis. Mechanistically, IAA upregulates key molecules involved in mucin sulfation, including 3'-phosphoadenosine 5'-phosphosulfate synthase 2 (Papss2) and solute carrier family 35 member B3 (Slc35b3), the synthesis enzyme and the transferase of 3'-phosphoadenosine-5'-phosphosulfate (PAPS), via the aryl hydrocarbon receptor (AHR). More importantly, AHR can directly bind to the transcription start site of Papss2. Oral administration of Lactobacillus reuteri, which can produce IAA, contributes to protecting against colitis and promoting mucin sulfation, while the modified L. reuteri strain lacking the iaaM gene (LactobacillusΔiaaM) and the ability to produce IAA fail to exhibit such effects. Overall, IAA enhances intestinal mucin sulfation through the AHR-Papss2-Slc35b3 pathway, contributing to the protection of intestinal homfeostasis.


A HFD can lead to the development of colitis by disrupting tryptophan metabolism in the gut microbiome and lowering levels of IAA. Supplementation with IAA has been shown to alleviate colitis in mice and improve intestinal barrier function. It is believed that IAA may activate the AHR to upregulate the expression of Papss2 and Slc35b3, promoting sulfation modification of mucins and protecting the intestinal barrier. HFD, high-fat diet; AHR, aryl hydrocarbon receptor; IAA, indole-3-acetic acid; Papss2, 3'-phosphoadenosine 5'-phosphosulfate synthase 2; Slc35b3, solute carrier family 35 member B3.


Assuntos
Microbioma Gastrointestinal , Homeostase , Ácidos Indolacéticos , Mucosa Intestinal , Mucinas , Animais , Humanos , Camundongos , Microbioma Gastrointestinal/efeitos dos fármacos , Mucinas/metabolismo , Ácidos Indolacéticos/metabolismo , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiologia , Camundongos Endogâmicos C57BL , Colite/microbiologia , Colite/metabolismo , Colite/induzido quimicamente , Limosilactobacillus reuteri/metabolismo , Doenças Inflamatórias Intestinais/metabolismo , Doenças Inflamatórias Intestinais/microbiologia , Doenças Inflamatórias Intestinais/tratamento farmacológico , Dieta Hiperlipídica/efeitos adversos , Masculino , Receptores de Hidrocarboneto Arílico/metabolismo , Receptores de Hidrocarboneto Arílico/genética , Modelos Animais de Doenças
7.
Nat Commun ; 15(1): 5874, 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-38997284

RESUMO

Mucus injury associated with goblet cell (GC) depletion constitutes an early event in inflammatory bowel disease (IBD). Using single-cell sequencing to detect critical events in mucus dysfunction, we discover that the Kazal-type serine protease inhibitor SPINK4 is dynamically regulated in colitic intestine in parallel with disease activities. Under chemically induced colitic conditions, the grim status in Spink4-conditional knockout mice is successfully rescued by recombinant murine SPINK4. Notably, its therapeutic potential is synergistic with existing TNF-α inhibitor infliximab in colitis treatment. Mechanistically, SPINK4 promotes GC differentiation using a Kazal-like motif to modulate EGFR-Wnt/ß-catenin and -Hippo pathways. Microbiota-derived diacylated lipoprotein Pam2CSK4 triggers SPINK4 production. We also show that monitoring SPINK4 in circulation is a reliable noninvasive technique to distinguish IBD patients from healthy controls and assess disease activity. Thus, SPINK4 serves as a serologic biomarker of IBD and has therapeutic potential for colitis via intrinsic EGFR activation in intestinal homeostasis.


Assuntos
Colite , Camundongos Knockout , Animais , Colite/genética , Colite/induzido quimicamente , Colite/patologia , Colite/tratamento farmacológico , Colite/metabolismo , Humanos , Camundongos , Células Caliciformes/metabolismo , Células Caliciformes/patologia , Células Caliciformes/efeitos dos fármacos , Receptores ErbB/metabolismo , Receptores ErbB/genética , Receptores ErbB/antagonistas & inibidores , Camundongos Endogâmicos C57BL , Inibidores de Serinopeptidase do Tipo Kazal/genética , Inibidores de Serinopeptidase do Tipo Kazal/metabolismo , Via de Sinalização Wnt/efeitos dos fármacos , Masculino , Doenças Inflamatórias Intestinais/genética , Doenças Inflamatórias Intestinais/metabolismo , Feminino , Modelos Animais de Doenças , Biomarcadores/sangue , Biomarcadores/metabolismo , Diferenciação Celular
8.
J Colloid Interface Sci ; 673: 1-8, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38870663

RESUMO

Heterojunctions photocatalysts play a crucial role in achieving high solar-hydrogen conversion efficiency. In this work, we mainly focus on the charge transfer dynamics and pathways for sulfides-based Schottky junctions in the photocatalytic water splitting process to clarify the mechanism of heterostructures photocatalysis. Sulfides-based Schottky junctions (CdS/CoP and CdS/1T-MoS2) were successfully constructed for photocatalytic water splitting. Because of the higher work function of CdS than that of CoP and 1T-MoS2, the direction of the built-in electric field is from CoP or 1T-MoS2 to semiconductor. Therefore, CoP and 1T-MoS2 can act as electrons acceptors to accelerate the transfer of photo-generated electron on the surface of CdS, thus improving the charge utilization efficiency. Meanwhile, CoP and 1T-MoS2 as active sites can also promote the water dissociation and lower the H+ reduction overpotential, thus contributing to the excellent photocatalytic hydrogen production activity (23.59 mmol·h-1·g-1 and 1195.8 mol·h-1·g-1 for CdS/CoP and CdS/1T-MoS2).

9.
Nanomaterials (Basel) ; 14(12)2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38921884

RESUMO

Photocatalysis represents a sustainable strategy for addressing energy shortages and global warming. The main challenges in the photocatalytic process include limited light absorption, rapid recombination of photo-induced carriers, and poor surface catalytic activity for reactant molecules. Defect engineering in photocatalysts has been proven to be an efficient approach for improving solar-to-chemical energy conversion. Sulfur vacancies can adjust the electron structure, act as electron reservoirs, and provide abundant adsorption and activate sites, leading to enhanced photocatalytic activity. In this work, we aim to elucidate the role of sulfur vacancies in photocatalytic reactions and provide valuable insights for engineering high-efficiency photocatalysts with abundant sulfur vacancies in the future. First, we delve into the fundamental understanding of photocatalysis. Subsequently, various strategies for fabricating sulfur vacancies in photocatalysts are summarized, along with the corresponding characterization techniques. More importantly, the enhanced photocatalytic mechanism, focusing on three key factors, including electron structure, charge transfer, and the surface catalytic reaction, is discussed in detail. Finally, the future opportunities and challenges in sulfur vacancy engineering for photocatalysis are identified.

10.
Tob Induc Dis ; 222024.
Artigo em Inglês | MEDLINE | ID: mdl-38686042

RESUMO

INTRODUCTION: This study aimed to investigate the effects of nicotine on the activation of pancreatic stellate cells (PSCs) and pancreatic fibrosis in chronic pancreatitis (CP), along with its underlying molecular mechanisms. METHODS: This was an in vivo and in vitro study. In vitro, PSCs were cultured to study the effects of nicotine on their activation and oxidative stress. Transcriptome sequencing was performed to identify potential signaling pathways involved in nicotine action. And the impact of nicotine on mitochondrial Ca2+ levels and Ca2+ transport-related proteins in PSCs was analyzed. The changes in nicotine effects were observed after the knockdown of the mitochondrial calcium uniporter (MCU) in PSCs. In vivo experiments were conducted using a mouse model of CP to assess the effects of nicotine on pancreatic fibrosis and oxidative stress in mice. The alterations in nicotine effects were observed after treatment with the MCU inhibitor Ru360. RESULTS: In vitro experiments demonstrated that nicotine promoted PSCs activation, characterized by increased cell proliferation, elevated α-SMA and collagen expression. Nicotine also increased the production of reactive oxygen species (ROS) and cellular malondialdehyde (MDA), exacerbating oxidative stress damage. Transcriptome sequencing revealed that nicotine may exert its effects through the calcium signaling pathway, and it was verified that nicotine elevated mitochondrial Ca2+ levels and upregulated MCU expression. Knockdown of MCU reversed the effects of nicotine on mitochondrial calcium homeostasis, improved mitochondrial oxidative stress damage and structural dysfunction, thereby alleviating the activation of PSCs. In vivo validation experiments showed that nicotine significantly aggravated pancreatic fibrosis in CP mice, promoted PSCs activation, exacerbated pancreatic tissue oxidative stress, and increased MCU expression. However, treatment with Ru360 significantly mitigated these effects. CONCLUSIONS: This study confirms that nicotine upregulates the expression of MCU, leading to mitochondrial calcium overload and exacerbating oxidative stress in PSCs, and ultimately promoting PSCs activation and exacerbating pancreatic fibrosis in CP.

11.
Ann Med ; 56(1): 2337712, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38614128

RESUMO

Background: Ulcerative colitis (UC), which is characterized by chronic relapsing inflammation of the colon, results from a complex interaction of factors involving the host, environment, and microbiome. The present study aimed to investigate the gut microbial composition and metabolic variations in patients with UC and their spouses. Materials and Methods: Fecal samples were collected from 13 healthy spouses and couples with UC. 16S rRNA gene amplicon sequencing and metagenomics sequencing were used to analyze gut microbiota composition, pathways, gene expression, and enzyme activity, followed by the Kyoto Encyclopedia of Genes and Genomes. Results: We found that the microbiome diversity of couples with UC decreased, especially that of UC patients. Bacterial composition, such as Firmicutes, was altered between UC patients and healthy controls, but was not significantly different between UC patients and their spouses. This has also been observed in pathways, such as metabolism, genetic information processing, organismal systems, and human diseases. However, the genes and enzymes of spouses with UC were not significantly different from those of healthy individuals. Furthermore, the presence of Faecalibacterium correlated with oxidative phosphorylation, starch and sucrose metabolism, amino sugar and nucleotide sugar metabolism, and the bacterial secretion system, showed a marked decline in the UC group compared with their spouses, but did not vary between healthy couples. Conclusion: Our study revealed that cohabitation with UC patients decreased differences in the gut microbiome between healthy individuals and patients. Not only was the composition and diversity of the microbiota diminished, but active pathways also showed some decline. Furthermore, Firmicutes, Faecalibacterium, and the four related pathways may be associated with the pathological state of the host rather than with human behavior.


Assuntos
Colite Ulcerativa , Microbioma Gastrointestinal , Microbiota , Humanos , Microbioma Gastrointestinal/genética , Colite Ulcerativa/genética , RNA Ribossômico 16S/genética , Inflamação
12.
Gut Microbes ; 16(1): 2329147, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38528729

RESUMO

BACKGROUND: Inflammatory bowel disease (IBD) is characterized by immune-mediated, chronic inflammation of the intestinal tract. The occurrence of IBD is driven by the complex interactions of multiple factors. The objective of this study was to evaluate the therapeutic effects of IAA in colitis. METHOD: C57/BL6 mice were administered 2.5% DSS in drinking water to induce colitis. IAA, Bifidobacterium pseudolongum, and R-equol were administered by oral gavage and fed a regular diet. The Disease Activity Index was used to evaluate disease activity. The degree of colitis was evaluated using histological morphology, RNA, and inflammation marker proteins. CD45+ CD4+ FOXP3+ Treg and CD45+ CD4+ IL17A+ Th17 cells were detected by flow cytometry. Analysis of the gut microbiome in fecal content was performed using 16S rRNA gene sequencing. Gut microbiome metabolites were analyzed using Untargeted Metabolomics. RESULT: In our study, we found IAA alleviates DSS-induced colitis in mice by altering the gut microbiome. The abundance of Bifidobacterium pseudolongum significantly increased in the IAA treatment group. Bifidobacterium pseudolongum ATCC25526 alleviates DSS-induced colitis by increasing the ratio of Foxp3+T cells in colon tissue. R-equol alleviates DSS-induced colitis by increasing Foxp3+T cells, which may be the mechanism by which ATCC25526 alleviates DSS-induced colitis in mice. CONCLUSION: Our study demonstrates that IAA, an indole derivative, alleviates DSS-induced colitis by promoting the production of Equol from Bifidobacterium pseudolongum, which provides new insights into gut homeostasis regulated by indole metabolites other than the classic AHR pathway.


Assuntos
Bifidobacterium , Colite , Microbioma Gastrointestinal , Doenças Inflamatórias Intestinais , Camundongos , Animais , Equol/metabolismo , Equol/farmacologia , Equol/uso terapêutico , RNA Ribossômico 16S/genética , Colite/induzido quimicamente , Colite/tratamento farmacológico , Colite/metabolismo , Ácidos Indolacéticos/metabolismo , Doenças Inflamatórias Intestinais/patologia , Inflamação/patologia , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Fatores de Transcrição Forkhead/farmacologia , Sulfato de Dextrana/toxicidade , Camundongos Endogâmicos C57BL , Modelos Animais de Doenças , Colo/metabolismo
13.
Chem Commun (Camb) ; 60(22): 3067-3070, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38386357

RESUMO

MnO2-Mn3O4 heterostructure materials are applied in aqueous magnesium ion energy storage for the first time. The heterostructure yields an exceptionally high pseudocapacitance contribution, resulting in a specific capacitance of 313.5 F g-1 at 1 A g-1, which contrasts with that of MnO2 (108.8 F g-1) and Mn3O4 (123.5 F g-1). Additionally, it shows potential for practical applications as a cathode for magnesium ion hybrid supercapacitors (MHS).

14.
ACS Omega ; 9(2): 2657-2663, 2024 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-38250417

RESUMO

This study explores the production of flash graphene (AC-FG) from anthracite coal by using the flash Joule heating (FJH) method. This study demonstrates that AC-FG can be derived from anthracite coal by precisely controlling the system parameters, specifically the pulse voltage. The FJH process requires no catalyst. The produced material was characterized by using Raman, XRD, XPS, TG, SEM, TEM, and XPS techniques. The results reveal that the degree of graphitization of coal reaches its peak at 190 V. From an energy perspective, FJH provides a straightforward and cost-effective method for graphene preparation, offering a substantial avenue for the efficient utilization of coal resources and the cost-effective application of graphene.

15.
Dalton Trans ; 53(4): 1640-1647, 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38167672

RESUMO

Manganese oxides are commonly employed as a cathode for magnesium ion storage in aqueous magnesium ion hybrid supercapacitors (MHS). However, sluggish reaction kinetics still hinders their practical application. Herein, we designed K-birnessite-MnO2 and electrostatically spun mulberry-like carbon composites (K-MnO2/HMCs) via an in situ growth technique. Benefiting from the 3D conductive carbon network substrate, the in situ fabricated K-MnO2 exhibits more active sites and provides more interfacial contact area between the electrode material and the electrolyte. This improvement enhances its conductivity, facilitating the rapid transfer of electrons, diffusion of ions, and redox reactions. As a result, K-MnO2/HMC-based MHS achieves a specific capacity of 168 mA h g-1 at 0.5 A g-1, simultaneously exhibiting a superior energy density of 111.1 W h kg-1 at a power density of 505 W kg-1. Furthermore, it demonstrates excellent high rate performance and a long cycling life for aqueous magnesium ion storage, offering new insights for MHS applications.

16.
Nat Commun ; 15(1): 227, 2024 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-38172093

RESUMO

Current treatment for functional dyspepsia (FD) has limited and unsustainable efficacy. Probiotics have the sustainable potential to alleviate FD. This randomized controlled clinical trial (Chinese Clinical Trial Registry, ChiCTR2000041430) assigned 200 FD patients to receive placebo, positive-drug (rabeprazole), or Bifidobacterium animalis subsp. lactis BL-99 (BL-99; low, high doses) for 8-week. The primary outcome was the clinical response rate (CRR) of FD score after 8-week treatment. The secondary outcomes were CRR of FD score at other periods, and PDS, EPS, serum indicators, fecal microbiota and metabolites. The CRR in FD score for the BL-99_high group [45 (90.0%)] was significantly higher than that for placebo [29 (58.0%), p = 0.001], BL-99_low [37 (74.0%), p = 0.044] and positive_control [35 (70.0%), p = 0.017] groups after 8-week treatment. This effect was sustained until 2-week after treatment but disappeared 8-week after treatment. Further metagenomic and metabolomics revealed that BL-99 promoted the accumulation of SCFA-producing microbiota and the increase of SCFA levels in stool and serum, which may account for the increase of serum gastrin level. This study supports the potential use of BL-99 for the treatment of FD.


Assuntos
Bifidobacterium animalis , Dispepsia , Probióticos , Humanos , Dispepsia/terapia , Probióticos/uso terapêutico , Fezes/microbiologia , Método Duplo-Cego
17.
J Pak Med Assoc ; 74(1): 26-31, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38219160

RESUMO

Objectives: To evaluate the efficacy of miniprobe endoscopic ultrasonography for the diagnosis and adjuvant treatment of patients with colorectal submucosal lesions. METHODS: The retrospective study was conducted at the Beijing Chao-Yang Hospital, Capital Medical University, China, and comprised data from January 1, 2016, to July 31, 2021, related to patients of either gender with colorectal submucosal lesions who underwent miniprobe endoscopic ultrasonography. The findings were compared with biopsy specimens and clinical diagnoses. Diagnostic features of miniprobe endoscopic ultrasonography were assessed along with its accuracy. Data was analysed using R 4.1.2. RESULTS: Of the 237 patients, 121(51.1%) were female and 116(48.9%) were male. The overall mean age was 55.6±12.9 years. Miniprobe endoscopic ultrasonography successfully imaged all 237(100%) colorectal submucosal lesions, and 188(79.3%) had consistent results compared to histopathological findings. The majority of lesions were <10mm 102(43.4%) or 10-19mm 84(35.7%) in size. Those detected with high echogenicity were 126(53.2%) and those with low/low-medium echogenicity were 83(35.0%). Tumour size 10-19mm and uneven echo quality significantly increased the accuracy of miniprobe endoscopic ultrasonography (p<0.05). CONCLUSIONS: Miniprobe endoscopic ultrasonography was able to provide precise information about the size, layer of origin, echogenicity and border of colorectal submucosal lesions, and had a high accuracy in the differential diagnosis of such lesions.


Assuntos
Neoplasias Colorretais , Endossonografia , Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Endossonografia/métodos , Estudos Retrospectivos , China , Diagnóstico Diferencial , Neoplasias Colorretais/diagnóstico por imagem , Neoplasias Colorretais/cirurgia , Neoplasias Colorretais/patologia
18.
J Colloid Interface Sci ; 657: 921-930, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38091915

RESUMO

As a typical spinel oxide, nickel cobaltite (NiCo2O4) is considered to be a promising and reliable oxygen evolution reaction (OER) catalyst due to its abundant oxidation states and the synergistic effect of multiple metal species. However, the electrocatalytic OER performance of NiCo2O4 has always been limited by the low specific surface area and poor intrinsic conductivity of spinels. Herein, the hedgehog-like molybdenum-doped NiCo2O4 (Mo-NiCo2O4) catalyst was prepared as an efficient OER electrocatalyst via a facile hydrothermal method followed with high-temperature annealing. The Mo-NiCo2O4-0.075 with Mo doping concentration of âˆ¼ 1.95 wt% exhibits excellent OER performance with a low overpotential of 265 mV at a current density of 10 mA·cm-2and a Tafel slope of 126.63 mV·dec-1, as well as excellent cyclingstability.The results demonstrated that the hedgehog-like structure provides Mo-NiCo2O4 with the high surface area and mesopores that enhance electrolyte diffusion and optimal active site exposure. The in-situ Raman spectra and density functional theory calculations show that the Mo cations doping improve the intrinsic conductivity of the NiCo2O4 while modulating the chemisorption of intermediates. Meanwhile, the energy barriers of *OH and O* formation decrease significantly after Mo doping, effectively facilitating water dissociation and optimizing the reaction kinetics.

19.
Small ; 20(12): e2307843, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37948442

RESUMO

Covalent organic frameworks (COFs) with flexible periodic skeletons and ordered nanoporous structures have attracted much attention as potential candidate electrode materials for green energy storage and efficient seawater desalination. Further improving the intrinsic electronic conductivity and releasing porosity of COF-based materials is a necessary strategy to improve their electrochemical performance. Herein, the employed graphene as the conductive substrate to in situ grow 2D redox-active COF (TFPDQ-COF) with redox activity under solvent-free conditions to prepare TFPDQ-COF/graphene (TFPDQGO) nanohybrids and explores their application in both supercapacitor and hybrid capacitive deionization (HCDI). By optimizing the hybridization ratio, TFPDQGO exhibits a large specific capacitance of 429.0 F g-1 due to the synergistic effect of the charge transport highway provided by the graphene layers and the abundant redox-active centers contained in the COF skeleton, and the assembled TFPDQGO//activated carbon (AC) asymmetric supercapacitor possesses a high energy output of 59.4 Wh kg-1 at a power density of 950 W kg-1 and good cycling life. Furthermore, the maximum salt adsorption capacity (SAC) of 58.4 mg g-1 and stable regeneration performance is attained for TFPDQGO-based HCDI. This study highlights the new opportunities of COF-based hybrid materials acting as high-performance supercapacitor and HCDI electrode materials.

20.
Small ; 20(21): e2309353, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38098371

RESUMO

Defect engineering is recognized as an attractive method for modulating the electronic structure and physicochemical characteristics of carbon materials. Exploiting heteroatom-doped porous carbon with copious active sites has attracted great attention for capacitive deionization (CDI). However, traditional methods often rely on the utilization of additional heteroatom sources and strong corrosive activators, suffering from low doping efficiency, insufficient doping level, and potential biotoxicity. Herein, hydrogen-bonded organic frameworks (HOFs) are employed as precursors to synthesize N, O co-doped porous carbon via a simple and green reverse defect engineering strategy, achieving controllable heavy doping of heteroatoms. The N, O co-doping triggers significant pseudocapacitive contribution and the surface pore structure supports the formation of the electric double layer. Therefore, when HOF-derived N, O co-doped carbon is used as CDI electrodes, a superior salt adsorption capacity of 32.29 ± 1.42 mg g-1 and an outstanding maximum salt adsorption rate of 10.58 ± 0.46 mg g-1 min-1 at 1.6 V in 500 mg L-1 NaCl solution are achieved, which are comparable to those of state-of-the-art carbonaceous electrodes. This work exemplifies the effectiveness of the reverse nitrogen-heavy doping strategy on improving the carbon structure, shedding light on the further development of rational designed electrode materials for CDI.

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