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1.
ACS Appl Mater Interfaces ; 16(22): 28402-28408, 2024 Jun 05.
Article in English | MEDLINE | ID: mdl-38768300

ABSTRACT

α-Phase formamidinium lead iodide (FAPbI3) perovskite solar cells (PSCs) have garnered significant attention, owing to their remarkable efficiency. Methylammonium chloride (MACl), a common additive, is used to control the crystallization of FAPbI3, thereby facilitating the formation of the photoactive α-phase. However, MACl's high volatility raises concerns regarding its stability and potential impact on the stability of the device. In this study, we partially substituted MACl with n-propylammonium chloride (PACl), which has a long alkyl chain, to promote the oriented crystallization of FAPbI3, ultimately forming an δ-phase-free perovskite. The FAPbI3 film containing PACl demonstrates an enhanced photoluminescence intensity and lifetime. Additionally, PACl's presence at grain boundaries acts as a protective layer for the PSCs. Consequently, we achieved a power conversion efficiency (PCE) of 22.4% and exceptional stability. It maintains over 95% of initial PCE for 100 days in an N2 glovebox, over 85% after 100 h of maximum power point tracking, and over 80% after 60 °C thermal aging.

2.
J Colloid Interface Sci ; 667: 303-311, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38640650

ABSTRACT

Metal selenides have emerged as promising Na-storage anode materials owing to their substantial theoretical capacity and high cost-effectiveness. However, the application of metal selenides is hindered by inferior electronic conductivity, huge volume variation, and sluggish kinetics of ionic migration. In response to these challenges, herein, a hierarchical hollow tube consisting of FeSe2 nanosheets and Se quantum dots anchored within a carbon skeleton (HT-FeSe2/Se/C) is strategically engineered and synthesized. The most remarkable feature of HT-FeSe2/Se/C is the introduction of Se quantum dots, which could lead to high electron density near the Fermi level and significantly enhance the overall charge transfer capability of the electrode. Moreover, the distinctive hollow tubular structure enveloped by the carbon skeleton endows the HT-FeSe2/Se/C anode with robust structural stability and fast surface-controlled Na-storage kinetics. Consequently, the as-synthesized HT-FeSe2/Se/C demonstrates a reversible capacity of 253.5 mAh/g at a current density of 5 A/g and a high specific capacity of 343.9 mAh/g at 1 A/g after 100 cycles in sodium-ion batteries (SIBs). Furthermore, a full cell is assembled with HT-FeSe2/Se/C as the anode, and a vanadium-based cathode (Na3V2(PO4)2O2F), showcasing a high specific capacity of 118.1 mAh/g at 2 A/g. The excellent performance of HT-FeSe2/Se/C may hint at future material design strategies and advance the development and application of SIBs.

3.
Phytochemistry ; 221: 114045, 2024 May.
Article in English | MEDLINE | ID: mdl-38460781

ABSTRACT

Plants attract beneficial insects and promote pollination by releasing floral scents. Salvia miltiorrhiza, as an insect-pollinated flowering plant, which has been less studied for its floral aroma substances. This study revealed that S. miltiorrhiza flowers produce various volatile terpenoids, including five monoterpenes and ten sesquiterpenes, with the sesquiterpene compound (E)-ß-caryophyllene being the most abundant, accounting for 28.1% of the total volatile terpenoids. Y-tube olfactometer experiments were conducted on the primary pollinator of S. miltiorrhiza, the Apis ceranas. The results indicated that (E)-ß-caryophyllene compound had an attractive effect on the Apis ceranas. By comparing the homologous sequences with the genes of (E)-ß-caryophyllene terpene synthases in other plants, the SmTPS1 gene was selected for further experiment. Subcellular localization experiments showed SmTPS1 localized in the cytoplasm, and its in vitro enzyme assay revealed that it could catalyze FPP into ß-Elemene, (E)-ß-caryophyllene and α-Humulene. Overexpression of SmTPS1 in S. miltiorrhiza resulted in a 5.29-fold increase in gene expression. The GC-MS analysis revealed a significant increase in the concentration of (E)-ß-caryophyllene in the transgenic plants, with levels 2.47-fold higher compared to the empty vector plants. Furthermore, Y-tube olfactometer experiments showed that the transgenic plants were significantly more attractive to Apis ceranas compared to the empty vector plants. Co-expression analysis suggested that four SmMYCs (SmMYC1, SmMYC5, SmMYC10, and SmMYC11) may be involved in the transcriptional regulation of SmTPS1. The yeast one-hybrid screen and the Dual luciferase assay indicated that SmMYC10 positively regulates the expression of SmTPS1. In conclusion, this study lays a foundation for the functional analysis and transcriptional regulation of terpene synthase genes in S. miltiorrhiza.


Subject(s)
Alkyl and Aryl Transferases , Polycyclic Sesquiterpenes , Salvia miltiorrhiza , Bees , Animals , Salvia miltiorrhiza/metabolism , Odorants , Terpenes/metabolism , Alkyl and Aryl Transferases/genetics , Alkyl and Aryl Transferases/metabolism , Flowers/metabolism , Gene Expression Regulation, Plant
4.
PeerJ ; 12: e16760, 2024.
Article in English | MEDLINE | ID: mdl-38250724

ABSTRACT

Dendrobium officinale Kimura et Migo is a tonic plant that has both ornamental and medicinal properties. Terpenoids are significant and diverse secondary metabolites in plants, and are one of the important natural active ingredients in D. officinale. The AP2/ERF gene family plays a major role in primary and secondary metabolism. However, the AP2/ERF transcription factor family has not been identified in D. officinale, and it is unclear if it is involved in the regulation of terpenoid biosynthesis. This study identified a sesquiterpene synthetase-ß-patchoulene synthase (DoPAES) using transcriptome and terpenic metabolic profile analyses. A total of 111 members of the AP2/ERF family were identified through the whole genome of D. officinale. The tissue-specific expression and gene co-expression pattern of the DoAP2/ERF family members were analyzed. The results showed that the expression of DoPAES was highly correlated with the expression of DoAP2/ERF89 and DoAP2/ERF47. The yeast one-hybrid (Y1H) assays and dual-luciferase experiments demonstrated that DoAP2/ERF89 and DoAP2/ERF47 could regulate the expression of DoPAES. The transcriptional regulatory effects were examined using homologous transient expression of DoAP2/ERF89 in protocorms of D. officinale. DoAP2/ERF89 positively regulated the biosynthesis of ß-patchoulene. This study showed that DoAP2/ERF89 can bind to the promoter region of DoPAES to control its expression and further regulate the biosynthesis of ß-patchoulene in D. officinale. These results provide new insights on the regulation of terpenoid biosynthesis.


Subject(s)
Alkyl and Aryl Transferases , Dendrobium , Dendrobium/genetics , Secondary Metabolism , Sesquiterpenes, Guaiane , Saccharomyces cerevisiae
5.
Front Plant Sci ; 14: 1162826, 2023.
Article in English | MEDLINE | ID: mdl-37546249

ABSTRACT

Terpenes are the main class of secondary metabolites produced in response to pest and germ attacks. In maize (Zea mays L.), they are the essential components of the herbivore-induced plant volatile mixture, which functioned as a direct or indirect defense against pest and germ attacks. In this study, 43 maize terpene synthase gene (ZmTPS) family members were systematically identified and analyzed through the whole genomes of maize. Nine genes, including Zm00001d032230, Zm00001d045054, Zm00001d024486, Zm00001d004279, Zm00001d002351, Zm00001d002350, Zm00001d053916, Zm00001d015053, and Zm00001d015054, were isolated for their differential expression pattern in leaves after corn borer (Ostrinia nubilalis) bite. Additionally, six genes (Zm00001d045054, Zm00001d024486, Zm00001d002351, Zm00001d002350, Zm00001d015053, and Zm00001d015054) were significantly upregulated in response to corn borer bite. Among them, Zm00001d045054 was cloned. Heterologous expression and enzyme activity assays revealed that Zm00001d045054 functioned as d-limonene synthase. It was renamed ZmDLS. Further analysis demonstrated that its expression was upregulated in response to corn borer bites and Fusarium graminearum attacks. The mutant of ZmDLS downregulated the expressions of Zm00001d024486, Zm00001d002351, Zm00001d002350, Zm00001d015053, and Zm00001d015054. It was more attractive to corn borer bites and more susceptible to F. graminearum infection. The yeast one-hybrid assay and dual-luciferase assay showed that ZmMYB76 and ZmMYB101 could upregulate the expression of ZmDLS by binding to the promoter region. This study may provide a theoretical basis for the functional analysis and transcriptional regulation of terpene synthase genes in crops.

6.
Int J Gen Med ; 16: 2285-2294, 2023.
Article in English | MEDLINE | ID: mdl-37304906

ABSTRACT

Background: Immune checkpoint inhibitors have achieved limited clinical effectiveness in colon cancer. Stem memory T cells (TSCMs) and in-situ cytotoxic T cells are dominant contributors to host immunity. Currently, data on the correlation between TSCM and T cell abundance and clinicopathological characteristics in colon cancer are largely unavailable. Methods: In-situ cytotoxic T cells are identified based on the quantification of CD3+ and CD8+ markers using immunohistochemistry (IHC) in the core of the tumor and the invasive margin of the tumor. The expression of representative markers of TSCMs, CD27 and CD95, was assayed using IHC in colon cancer tissues. Correlations between the levels of each marker and the clinicopathological characteristics as well as prognosis were evaluated. Results: High densities of CD3+ and CD8+ T cells correlated with stage I-II tumors, whereas a lower infiltration of cytotoxic T cells correlated with advanced-stage tumors. CD27 and CD95 were both expressed in the membrane of T cells present in the tumor stroma and their levels showed a negative correlation with the TNM stage. CD3, CD8, and CD27 were expressed at the same locations simultaneously, indicating their coordinated action against cancer. In addition, cytotoxic T cell densities and CD27 and CD95 expression remained independent prognostic factors for overall survival. Conclusion: In-situ cytotoxic T cells and TSCMs play important roles in colon cancer development. TSCMs marker CD27 and CD95 were both indicators of survival in patients with colon cancer. Thus, it is believed that TSCMs represent a desirable population for future use in combination immunotherapy.

7.
Int J Gen Med ; 16: 1757-1769, 2023.
Article in English | MEDLINE | ID: mdl-37193249

ABSTRACT

Background: Immunotherapy drugs, immune checkpoint inhibitors (ICIs), have been approved for first- and second-line treatment of non-small cell lung cancer (NSCLC), but only a portion of patients respond to ICIs. It is crucial to screen the beneficiaries of immunotherapy through biomarkers accurately. Methods: Several datasets were used to explore the predictive value for immunotherapy and immune relevance of guanylate binding protein 5 (GBP5) in NSCLC, including the GSE126044 dataset, The Cancer Genome Atlas (TCGA) dataset, Clinical Proteomic Tumor Analysis Consortium (CPTAC) dataset, the Kaplan-Meier plotter dataset, the HLuA150CS02 cohort, and the HLugS120CS01 cohort. Results: GBP5 was upregulated in tumor tissues but associated with a good prognosis in NSCLC. Moreover, our findings demonstrated that GBP5 was strongly correlated with the expression of many immune-related genes, TIIC levels, and PD-L1 expression based on RNA-seq data onto online databases and validation of the NSCLC tissue microarray using IHC staining. Moreover, pan-cancer analysis has shown that GBP5 was a factor in identifying immuno-hot tumors, except for a few tumor types. Conclusion: In summary, our current research suggests that GBP5 expression is a potential biomarker for predicting the outcome of NSCLC patients treated with ICIs. More research with large-scale samples is needed to determine their value as biomarkers of ICIs benefit.

9.
Front Genet ; 13: 969723, 2022.
Article in English | MEDLINE | ID: mdl-36159996

ABSTRACT

With continued advances in cancer research, the crucial role of the tumor microenvironment (TME) in regulating tumor progression and influencing immunotherapy outcomes has been realized over the years. A series of studies devoted to enhancing the response to immunotherapies through exploring efficient predictive biomarkers and new combination approaches. The microfluidic technology not only promoted the development of multi-omics analyses but also enabled the recapitulation of TME in vitro microfluidic system, which made these devices attractive across studies for optimization of immunotherapy. Here, we reviewed the application of microfluidic systems in modeling TME and the potential of these devices in predicting and monitoring immunotherapy effects.

10.
Front Plant Sci ; 13: 941231, 2022.
Article in English | MEDLINE | ID: mdl-35937364

ABSTRACT

Dendrobium officinale is both a traditional herbal medicine and a plant of high ornamental and medicinal value. Alkaloids, especially terpenoid indole alkaloids (TIAs), with pharmacological activities are present in the tissues of D. officinale. A number of genes involved in alkaloid biosynthetic pathways have been identified. However, the regulatory mechanisms underlying the precursor and methyl jasmonate (MeJA)-induced accumulation of alkaloids in D. officinale are poorly understood. In this study, we collected D. officinale protocorm-like bodies (PLBs) and treated them with TIA precursors (tryptophan and secologanin) and MeJA for 0 (T0), 4 (T4) and 24 h (T24); we also established control samples (C4 and C24). Then, we measured the total alkaloid content of the PLBs and performed transcriptome sequencing using the Illumina HiSeq 2,500 system. The total alkaloid content increased significantly after 4 h of treatment. Go and KEGG analysis suggested that genes from the TIA, isoquinoline alkaloid, tropane alkaloid and jasmonate (JA) biosynthetic pathways were significantly enriched. Weighted gene coexpression network analysis (WGCNA) uncovered brown module related to alkaloid content. Six and seven genes related to alkaloid and JA bisosynthetic pathways, respectively, might encode the key enzymes involved in alkaloid biosynthesis of D. officinale. Moreover, 13 transcription factors (TFs), which mostly belong to AP2/ERF, WRKY, and MYB gene families, were predicted to regulate alkaloid biosynthesis. Our data provide insight for studying the regulatory mechanism underlying TIA precursor and MeJA-induced accumulation of three types of alkaloids in D. officinale.

11.
Front Immunol ; 13: 900119, 2022.
Article in English | MEDLINE | ID: mdl-35812375

ABSTRACT

Background: Cancer of unknown primary (CUP) is heterogeneous and has a wide variety of clinical presentations and a poor prognosis in most patients, with a median overall survival of only 6 months. The development of molecular profiling contributes to precision therapy, and targeted drugs and immune checkpoint inhibitors (ICIs) greatly promote individualized treatment. Case presentation: Here, we reported a case of an unfavorable subset of CUP who had a long time of survival after the immunotherapy-prominent comprehensive treatment. A 48-year-old man presented with back pain and a cough. A diagnostic work-up showed bone marrow, multiple bones, and lymph node metastasis. Lymph node pathology implies metastatic poorly differentiated cancer. Next-generation sequencing (NGS) showed no special targets, but the tumor proportion score (TPS) of programmed death-ligand 1 (PD-L1) was 80% and the tumor mutation burden (TMB) was 16.7 per million bases. After two cycles of pembrolizumab 200 mg D1 plus nanoparticle albumin-bound (nab)-paclitaxel 200 mg D1&8 (q3w), PET-CT and bone marrow aspiration cytology showed a complete response (CR). Subsequently, pembrolizumab alone was used for three months. The left inguinal lymph nodes showed new metastasis. After two cycles of the combination treatment of pembrolizumab and (nab)-paclitaxel, a partial response (PR) was achieved. After seven months, retroperitoneal lymph nodes showed new metastasis, and the sequential treatment with radiotherapy and pembrolizumab exhibited encouraging efficacy. To date, the patient has survived nearly 40 months with the combination therapy. Conclusions: The ICI-prominent comprehensive treatment provided clinical benefit for the reported case of CUP. Thus, CUP patients with markers of benefiting from immunotherapy should be actively treated with immunotherapy to improve their prognosis.


Subject(s)
Neoplasms, Unknown Primary , Humans , Immunotherapy , Male , Middle Aged , Neoplasms, Unknown Primary/therapy , Paclitaxel , Positron Emission Tomography Computed Tomography , Prognosis
12.
Front Plant Sci ; 13: 943788, 2022.
Article in English | MEDLINE | ID: mdl-35898219

ABSTRACT

Dendrobium officinale Kimura et Migo is a famous Chinese herb. D. officinale grows on rocks where the available phosphorus is low. The SPX family plays a critical role in maintaining Pi homeostasis in plants. In this paper, 9 SPX family genes were identified in the genome of D. officinale. Bioinformatics and qRT-PCR analysis showed that DoSPXs were involved in response to -Pi stress and had different expression patterns. DoSPX4, which had a unique expression pattern, was clustered with AtSPX4 and OsSPX4. Under -Pi treatment, the expression level of DoSPX4 reached a peak on 5 d in roots, while showing a downward trend in the aboveground parts. DoSPX4 was located on the cell membrane. Overexpression DoSPX4 promoted Pi content in the stem and the expression level of NtPHT1/2 in Nicotiana tabacum. The results of Yeast two-hybrid showed that DoSPX4 could interact with Phosphate High-Affinity Response factor (DoPHR2). These results highlight the role of DoSPX4 in response to low phosphorus, which provides a theoretical basis for further study on the response mechanism of -Pi in D. officinale.

14.
J Oncol ; 2022: 3224373, 2022.
Article in English | MEDLINE | ID: mdl-35242187

ABSTRACT

OBJECTIVE: To investigate the regulatory effect of ZEB1 on PD-L1 expression and the pharmacodynamic effects of Biochanin A on the malignant biological behaviors of colorectal cancer (CRC). METHODS: The correlation between epithelial-mesenchymal transition (EMT) score and features of the tumor microenvironment (TME) was investigated using the Cancer Genome Atlas (TCGA) dataset. The correlation between ZEB1 and PD-L1 expression was validated using immunohistochemistry (IHC) staining, and the regulatory effect of ZEB1 on PD-L1 expression was explored by in vitro assays. Moreover, the pharmacodynamic effects of Biochanin A on ZEB1 and PD-L1 expression, as well as malignant biological behaviors of CRC cells, were evaluated by in vitro and in vivo assays. RESULTS: EMT score was positively correlated with a majority of immunostimulators, immune checkpoints, activities of antitumor immunity cycles, and infiltration levels of most immune cells in the TCGA dataset. In addition, ZEB1 was correlated with and positively regulated PD-L1 expression in CRC. Besides, Biochanin A, an inhibitor for the ZEB1/PD-L1 axis, notably inhibited ZEB1-mediated aggressiveness and PD-L1 expression of CRC cells. Moreover, Biochanin A also exerted a tumor-inhibitory role in vivo in the CRC mouse model. CONCLUSION: Overall, we found that ZEB1 is a main regulator of PD-L1 expression in CRC. In addition, we also identified Biochanin A as a novel inhibitor for the ZEB1/PD-L1 axis, which could inhibit tumor progression and immune escape.

15.
Phytochemistry ; 190: 112847, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34237478

ABSTRACT

Liverworts (Marchantiophyta) are among the earliest diverging lineages of extant land plants. Among their unique features, most liverworts contain membrane-bound oil bodies, organelles that accumulate diverse secondary metabolites, especially terpenoids. In contrast to the rich information on liverwort terpenoid chemistry, little is known about their biosynthesis. Recently, terpenoid biosynthesis was studied in a model thalloid species Marchantiapolymorpha, in which sesquiterpenes and monoterpenes are biosynthesized by a new type of terpene synthases termed microbial terpene synthase-like (MTPSL) proteins. Here we study terpenoid biosynthesis in a leafy liverwort Radula lindenbergiana. Vegetative plants of R.lindenbergiana were found to contain a mixture of sesquiterpenes, with (E,E)-α-farnesene/ß-curcumene and (Z)-ß-bisabolene being the most abundant constituents. From the analysis of the R. lindenbergiana transcriptome, five full-length MTPSL genes were identified. They were designated RlMTPSL1-5, respectively. Recombinant RlMTPSL proteins were produced in Escherichia coli and tested for sesquiterpene synthase activities using farnesyl diphosphate (FPP) as substrate. All except RlMTPSL5 were demonstrated to catalyze the formation of different sesquiterpenes. RlMTPSL1 produced multiple sesquiterpenes with eremophilene and an unidentified sesquiterpene as major products. The major products of RlMTPSL2 and RlMTPSL3 were ß-elemene and an unidentified sesquiterpene, respectively. RlMTPSL4 was also a multi-product sesquiterpene synthase with an unidentified sesquiterpene being the major product. Homology-based structural modeling was performed to understand the structural basis underlying different product profiles of the RlMTPSLs proteins. Most of the sesquiterpene products of the four active RlMTPSLs were also detected in R. lindenbergiana plants. Expression levels of the four RlMTPSL genes encoding active enzymes in vegetative plants were compared. In phylogenetic analysis, RlMTPSL genes were found to cluster together, indicating lineage-specific expansion of MTPSL genes in lineages leading to R.lindenbergiana and M. polymorpha. This study strengthens evidence for the contribution of MTPSL genes to terpenoid biosynthesis in liverworts.


Subject(s)
Alkyl and Aryl Transferases , Hepatophyta , Sesquiterpenes , Alkyl and Aryl Transferases/genetics , Phylogeny , Terpenes , Transcriptome
16.
Front Genet ; 12: 661296, 2021.
Article in English | MEDLINE | ID: mdl-33968137

ABSTRACT

Dendrobium officinale is a kind of traditional Chinese herbal medicine. Its flowers could be used as health care tea for its aroma flavor and medicinal value. Most recent studies demonstrated that terpenoids are the main components of the aromatic compounds in the flowers, but the biosynthesis of terpenoids is poorly understood in D. officinale. In the experiment, the flowers from two cultivars of D. officinale with different smells were collected. The transcriptome analysis and combined volatile terpenoids determination were performed to identify the genes related to the biosynthesis of the terpenoids. The results showed that the different products of volatile terpenoids are α-thujene, linalool, α-terpineol, α-phellandrene, γ-muurolene, α-patchoulene, and δ-elemene in two cultivar flowers. The transcriptome analysis detected 25,484 genes in the flowers. And 18,650 differentially expressed genes were identified between the two cultivars. Of these genes, 253 genes were mapped to the terpenoid metabolism pathway. Among these genes, 13 terpene synthase (TPS) genes may have correlations with AP2/ERF, WRKY, MYB, bHLH, and bZIP transcription factors by weighted gene co-expression network analysis (WGCNA). The transcription factors have regulatory effects on TPS genes. These results may provide ideas for the terpenoid biosynthesis and regulatory network of D. officinale flowers.

17.
PeerJ ; 8: e9781, 2020.
Article in English | MEDLINE | ID: mdl-32953268

ABSTRACT

MYB transcription factors play important roles in different plant biological processes during plant growth, development and stress response. In this study, 101 (DoMYB1-101) and 99 (PaMYB1-99) R2R3-MYB genes were identified in the genomes of Dendrobium officinale and Phalaenopsis aphrodite, respectively. To classify the isolated candidate genes, the R2R3-MYB genes from A. thaliana were selected as references. As a result, all identified DoMYB and PaMYB genes were classified into 22 subfamilies. Phylogenetic analysis revealed that S21 had the largest number of members of all the subfamilies. The numbers of introns, exons and conserved sequences in all of the identified genes are different. In addition, 20 DoMYB genes from six subfamilies were selected for further analysis of tissue-specific expression and responses to various abiotic stresses treatments. The results showed that all of the DoMYB genes in S4 and S19 subfamilies exhibited the highest relative expression levels in flowers. And five DoMYB genes including DoMYB31, DoMYB40, DoMYB49, DoMYB52 and DoMYB54, responded to the stress response. These results may provide useful information for further studies of the R2R3-MYB gene family.

18.
Chemistry ; 26(60): 13652-13658, 2020 Oct 27.
Article in English | MEDLINE | ID: mdl-32598040

ABSTRACT

Binary transition-metal oxides (BTMOs) with hierarchical micro-nano-structures have attracted great interest as potential anode materials for lithium-ion batteries (LIBs). Herein, we report the fabrication of hierarchical cauliflower-like CoFe2 O4 (cl-CoFe2 O4 ) via a facile room-temperature co-precipitation method followed by post-synthetic annealing. The obtained cauliflower structure is constructed by the assembly of microrods, which themselves are composed of small nanoparticles. Such hierarchical micro-nano-structure can promote fast ion transport and stable electrode-electrolyte interfaces. As a result, the cl-CoFe2 O4 can deliver a high specific capacity (1019.9 mAh g-1 at 0.1 A g-1 ), excellent rate capability (626.0 mAh g-1 at 5 A g-1 ), and good cyclability (675.4 mAh g-1 at 4 A g-1 for over 400 cycles) as an anode material for LIBs. Even at low temperatures of 0 °C and -25 °C, the cl-CoFe2 O4 anode can deliver high capacities of 907.5 and 664.5 mAh g-1 at 100 mA g-1 , respectively, indicating its wide operating temperature. More importantly, the full-cell assembled with a commercial LiFePO4 cathode exhibits a high rate performance (214.2 mAh g-1 at 5000 mA g-1 ) and an impressive cycling performance (612.7 mAh g-1 over 140 cycles at 300 mA g-1 ) in the voltage range of 0.5-3.6 V. Kinetic analysis reveals that the electrochemical performance of cl-CoFe2 O4 is dominated by pseudocapacitive behavior, leading to fast Li+ insertion/extraction and good cycling life.

19.
ACS Appl Mater Interfaces ; 11(51): 47886-47893, 2019 Dec 26.
Article in English | MEDLINE | ID: mdl-31797668

ABSTRACT

The intrinsic charge-transfer property bears the primary responsibility for the sluggish redox kinetics of the common electrode materials, especially operated at low temperatures. Herein, we report the crafting of homogeneously confined Fe7Se8 nanoparticles with a well-defined graphitic carbon matrix that demonstrate a highly efficient charge-transfer system in a designed natural coral-like structure (cl-Fe7Se8@C). Notably, the intricate architecture as well as highly conductive peculiarity of C concurrently satisfy the demands of achieving fast ionic/electrical conductivities for both Li/Na-ion batteries in a wide temperature range. For example, when cl-Fe7Se8@C is employed as the anode material to assemble full batteries with the cathode of Na3V2(PO4)2O2F (NVPOF), decent capacities of 323.1 and 175.9 mA h g-1 can be acquired at temperatures of 25 and -25 °C, respectively. This work is significant for further developing potential anode materials for advanced energy storage and conversion under low-temperature conditions.

20.
Chemistry ; 25(66): 15173-15181, 2019 Nov 27.
Article in English | MEDLINE | ID: mdl-31544301

ABSTRACT

Owing to low ion/electron conductivity and large volume change, transitional metal dichalcogenides (TMDs) suffer from inferior cycle stability and rate capability when used as the anode of lithium-ion batteries (LIBs). To overcome these disadvantages, amorphous molybdenum sulfide (MoSx ) nanospheres were prepared and coated with an ultrathin carbon layer through a simple one-pot reaction. Combining X-ray photoelectron spectroscopy (XPS) with theoretical calculations, MoSx was confirmed as having a special chain molecular structure with two forms of S bonding (S2- and S2 2- ), the optimal adsorption sites of Li+ were located at S2 2- . As a result, the MoSx electrode exhibits superior cycle and rate capacities compared with crystalline 2H-MoS2 (e.g., delivering a high capacity of 612.4 mAh g-1 after 500 cycles at 1 A g-1 ). This is mainly attributed to more exposed active S2 2- sites for Li storage, more Li+ transfer pathways for improved ion conductivity, and suppressed electrode structure pulverization of MoSx derived from the inherent chain-like molecular structure. Quantitative charge storage analysis further demonstrates the improved pseudocapacitive contribution of amorphous MoSx induced by fast reaction kinetics. Moreover, the morphology contrast after cycling demonstrates the dispersion of active materials is more uniform for MoSx than 2H-MoS2 , suggesting the MoSx can well accommodate the volume stress of the electrode during discharging. Through regulating the molecular structure, this work provides an effective targeted strategy to overcome the intrinsic issues of TMDs for high-performance LIBs.

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