Scalable syntheses of three-dimensional graphene nanoribbon aerogels from bacterial cellulose for supercapacitors.

Three-dimensional (3D) carbon aerogels with well-defined structures, e.g. high specific surface area (SSA), appropriate pore size distribution, good electrical conductivity and ideal building blocks, have been regarded as promising electrode materials or substrates for incorporation with pseudocapacitive materials for energy storage and conversion applications. Herein, we report a simple and scalable sonochemical method followed by a chemical activation process to transform bacterial cellulose-derived carbon nanofiber aerogels (CNFAs) into 3D graphene nanoribbon aerogels (GNRAs) for supercapacitors. Benefiting from a high SSA, reasonable pore size distribution and good conductivity, the GNRA electrode demonstrates a long cyclability, good rate capability and high charge storage performance for supercapacitors, yielding more than 1.5 times (three-electrode cell) and 2.6 times (two-electrode cell) the gravimetric capacitance of the CNFA electrode. In addition, a hybrid Ni-Co layered double hydroxides (LDHs)@GNRAs electrode achieves an impressive gravimetric capacitance of 968 F g-1 (based on the mass of the active material) at a current density of 1 A g-1. Moreover, an asymmetric supercapacitor device with a remarkable energy density of 29.87 Wh kg-1, wide working voltage windows of 1.6 V and good cycling stability (63.5% retention after 10 000 cycles) is achieved by using the GNRA as an anode and the Ni-Co LDHs@GNRAs as a cathode.

Mesh-Like Carbon Nanosheets with High-Level Nitrogen Doping for High-Energy Dual-Carbon Lithium-Ion Capacitors.

Li-ion capacitors (LICs) have demonstrated great potential for bridging the gap between lithium-ion batteries and supercapacitors in electrochemical energy storage area. The main challenge for current LICs (contain a battery-type anode as well as a capacitor-type cathode) lies in circumventing the mismatched electrode kinetics and cycle degradation. Herein, a mesh-like nitrogen (N)-doped carbon nanosheets with multiscale pore structure is adopted as both cathode and anode for a dual-carbon type of symmetric LICs to alleviate the above mentioned problems via a facile and green synthesis approach. With rational design, this dual-carbon LICs exhibits a broad high working voltage window (0-4.5 V), an ultrahigh energy density of 218.4 Wh kg - 1 electrodes ( 229.8 Wh L - 1 electrodes ), the highest power density of 22.5 kW kg - 1 electrodes ( 23.7 kW L - 1 electrodes ) even under an ultrahigh energy density of 97.5 Wh kg - 1 electrodes ( 102.6 Wh L - 1 electrodes ), as well as reasonably good cycling stability with capacity retention of 84.5% (only 0.0016% capacity loss per cycle) within 10 000 cycles under a high current density of 5 A g-1 . This study provides an efficient method and option for the development of high performance LIC devices.

Vertically aligned cobalt oxide nanowires on graphene networks for high-performance lithium storage.

Despite various electrochemically active materials, such as metals, metal oxides and sulfides, which have been widely utilized for lithium storage, these materials still encounter unsatisfied electrochemical performances including low reversible capacity, slow charge-discharge capability and poor cycle performance. Here, we demonstrate a simple approach to fabricate one-dimensional CoO nanowires vertically aligned on a 3D graphene network (denoted as a 3D CoO/graphene network) via a wet chemistry process. The resulting CoO/graphene network possesses an interconnected graphene network, hierarchical pores and a carpet-like structure. This unique network can (1) facilitate the easy access of the electrolyte, (2) prevent the aggregation of CoO nanowires, (3) accommodate the volume change of CoO during the cycle processes, (4) maintain a high electrical conductivity for the overall electrode and (5) give rise to a high content of CoO in the composite (∼92 wt%). As a result, the 3D CoO/graphene network can be directly used as an anode material without any binder or conductive additives for lithium storage, and it exhibits a high capacity of 857 mAh g(-1), an excellent rate capability and good cycle performance. We believe that such a simple but efficient protocol will provide a new pathway for the fabrication of various 3D metal or metal oxide-graphene networks for wide applications in such fields as energy storage, sensors and catalysts.

Building 3D structures of vanadium pentoxide nanosheets and application as electrodes in supercapacitors.

Various two-dimensional (2D) materials have recently attracted great attention owing to their unique properties and wide application potential in electronics, catalysis, energy storage, and conversion. However, large-scale production of ultrathin sheets and functional nanosheets remains a scientific and engineering challenge. Here we demonstrate an efficient approach for large-scale production of V2O5 nanosheets having a thickness of 4 nm and utilization as building blocks for constructing 3D architectures via a freeze-drying process. The resulting highly flexible V2O5 structures possess a surface area of 133 m(2) g(-1), ultrathin walls, and multilevel pores. Such unique features are favorable for providing easy access of the electrolyte to the structure when they are used as a supercapacitor electrode, and they also provide a large electroactive surface that advantageous in energy storage applications. As a consequence, a high specific capacitance of 451 F g(-1) is achieved in a neutral aqueous Na2SO4 electrolyte as the 3D architectures are utilized for energy storage. Remarkably, the capacitance retention after 4000 cycles is more than 90%, and the energy density is up to 107 W·h·kg(-1) at a high power density of 9.4 kW kg(-1).

Direct laser-patterned micro-supercapacitors from paintable MoS2 films.

Micrometer-sized electrochemical capacitors have recently attracted attention due to their possible applications in micro-electronic devices. Here, a new approach to large-scale fabrication of high-capacitance, two-dimensional MoS2 film-based micro-supercapacitors is demonstrated via simple and low-cost spray painting of MoS2 nanosheets on Si/SiO2 chip and subsequent laser patterning. The obtained micro-supercapacitors are well defined by ten interdigitated electrodes (five electrodes per polarity) with 4.5 mm length, 820 µm wide for each electrode, 200 µm spacing between two electrodes and the thickness of electrode is ∼0.45 µm. The optimum MoS2 -based micro-supercapacitor exhibits excellent electrochemical performance for energy storage with aqueous electrolytes, with a high area capacitance of 8 mF cm(-2) (volumetric capacitance of 178 F cm(-3) ) and excellent cyclic performance, superior to reported graphene-based micro-supercapacitors. This strategy could provide a good opportunity to develop various micro-/nanosized energy storage devices to satisfy the requirements of portable, flexible, and transparent micro-electronic devices.

Manipulating hydrogen and coordination bond chemistry for reversible zinc metal anodes.

Aqueous zinc ion hybrid capacitors (ZHCs) are promising as electrochemical energy storage devices due to their safety and cost-effectiveness. However, the practical application of aqueous ZHCs is impeded by zinc dendrite growth and side reactions induced by H2O during long-term cycling. Herein, an organic small molecule, dimethyl sulfoxide (DMSO), is elaborately introduced into 2 M ZnSO4 electrolyte to simultaneously overcome these challenges. As convincingly evidenced by experimental and theoretical results, the DMSO reconstructs the Zn[(H2O)6]2+ structure and original hydrogen bond networks at the molecular level. By forming coordination bonds with Zn2+ and hydrogen bonds with H2O due to the stronger electron donating ability of oxygen in molecule, DMSO establishes a Zn2+ solvation shell structure that inhibits H2O decomposition and dendrite growth. As a proof of concept, the implementation of this hybrid electrolyte in a Zn||Cu asymmetrical cell results in a high Coulombic efficiency (CE) of over 99.8% for 568 cycles at a current density of 2 mA cm-2. Furthermore, the full cells using this hybrid electrolyte coupled with activated carbon (AC) cathode can operate for over 30,000 cycles. These results suggest that reconstructing the solvation structure and hydrogen bond networks guide the design of electrolytes for the development of high-performance aqueous ZHCs.

Artificial bi-functional layers promoting Zn2+ desolvation and homogeneous deposition for reversible zinc metal anodes.

Rechargeable aqueous zinc-ion hybrid supercapacitors (ZHSs) are drawing extensive attention because of their cost-effectiveness and diminished safety hazards. Nevertheless, large-scale application of ZHSs has been hindered by the severe side reactions and rampant dendrites growth on the surface of Zn metal anodes. Herein, we propose a three-dimensional organic-inorganic composite frame material as an artificial bi-functional layer coated on the zinc foil, featuring nitrogenous functional groups with zincophilicity (abbreviated as NCFM@Zn). The nitrogen (N) site's strong adsorption capacity and synergistic effect of the sub-nanopore size promote rapid desolvation of zinc ions and reduce side reactions, while also prolonging galvanized nucleation's Sand's time and allowing for even nucleation. Moreover, the uniform distribution of N on the layer results in homogeneous zinc ions flux and supports consistent zinc plating while inhibiting dendrites generation. As a result of this unique artificial bi-functional layer, symmetric Zn cells can survive 2500 h at 2.5 mA cm-2. High-areal-capacity zinc||activated carbon hybrid supercapacitors also demonstrate 20,000 cycles at high Coulombic efficiency, thus highlighting the utter convenience and potential of this strategy for modifying rechargeable metal hybrid supercapacitor surfaces.

Unlocking Zinc-Ion Energy Storage Performance of Onion-Like Carbon by Promoting Heteroatom Doping Strategy.

Onion-like carbon (OLC) is one kind of a quasi-nanosphere with a concentric graphite shell structure and abundant mesopores, which is appropriate for a high rate of charging/discharging and long-lifespan cycling. However, the moderate specific surface area seriously impeded its capacitance performance in comparison with activated carbon and porous carbon. Herein, we have unlocked the Zn ion storage performance of OLC material through introducing N and P dopants. Benefitting from the fabricated N,P-OLC with a fully accessible external surface area for ion adsorption, high proportion of mesopores for fast ion migration, and synergistic effect of N and P co-doping in a carbon matrix favoring chemical adsorption of Zn2+ ions, when applied as a cathode electrode for Zn ion hybrid supercapacitors (ZHSCs), such a device can deliver a high specific capacitance of 420.3 F g-1 (184.5 mA h g-1) at 0.5 A g-1, an outstanding capacitance retention capability of 262.7 F g-1 even at 20 A g-1 (∼63% capacitance retention), a high energy density of 149.5 W h kg-1, and a high power density of 26.7 kW kg-1. Furthermore, this N,P-OLC material can in situ tightly integrate with a carbon cloth (CC) or carbon fiber to construct a freestanding and flexible electrode. The fabricated Zn//N,P-OLC@CC device achieved a high energy density of 85.3 mW h cm-2, a high power density of 24.3 W cm-2, and a long-term cycling lifespan (77.8% after 50 000 cycles). At last, the assembled quasi-solid-state fiber-shaped ZHSCs also present excellent flexibility and practicality. Our study exhibits that OLC can act as a promising carbon electrode for ZHSCs.

Frequency and clinical impact of WT1 mutations in the context of CEBPA-mutated acute myeloid leukemia.

INTRODUCTION: Several studies have confirmed that mutations in the Wilms tumor 1 (WT1) gene occur in adult acute myeloid leukemia (AML). However, few data are available regarding the incidence of WT1 mutations in CEBPAmut AML and their impact. METHODS: We retrospectively analyzed the frequency and clinical impact of WT1 mutations in 220 newly diagnosed AML patients with CEBPA mutations(CEBPAmut). Chromosome karyotype analysis was performed by R or G banding method and further confirmed either by fluorescence in situ hybridization (FISH) and/or by multiple reverse transcription polymerase chain reaction (multiple RT-PCR). Mutations were detected with a panel of 112mutational genes using next-generation sequencing (NGS). RESULTS: Overall, 30 WT1 mutations were detected in 29 of the 220 CEBPAmut AML patients (13.18%) screened. These mutations clustered overwhelmingly in exon 7 (n=16). WT1 mutations were found to be significantly more frequent in AML patients with double-mutated CEBPA (CEBPAdm) than in AML patients with single-mutated CEBPA (17.36%vs. 8.08%, P = 0.043). Among WT1-mutated patients, the most common co-mutation was FLT3-ITD (n = 7, 24.14%), followed by NRAS (n = 5, 17.24%), CSF3R (n = 4, 13.79%), GATA2 (n = 4, 13.79%), and KIT (n = 4, 13.79%). The most frequent functional pathway was signaling pathways inas many as 62.07% of cases. Notably,the concomitant mutations in epigenetic regulatorswere inversely correlated with WT1 mutations(P = 0.003). CEBPAdm AML patients with WT1 mutations had inferior relapse-free survival, event-free survival and overall survival compared with patients CEBPAdm AML without WT1 mutations (P = 0.002, 0.004, and 0.010, respectively). CONCLUSION: Our data showed that WT1 mutations are frequently identified in CEBPAmut AML, especially in CEBPAdm AML. CEBPAmut AML patients with WT1 mutations show distinct spectrum of comutations. In the context of CEBPAdm AML, WT1 mutations predict a poor prognosis.

Companion gene mutations and their clinical significance in AML with double or single mutant CEBPA.

INTRODUCTION: We report the co-mutations in AML with CEBPAsm or CEBPAdm and their clinical features in a large cohort (n = 302) of CEBPAmut AML patients. MATERIALS AND METHODS: We retrospectively sequenced 112 genes in 302 patients with CEBPAmut using NGS, and studied the spectrum and clinical impact of co-mutations in CEBPAdm and CEBPAsm. RESULTS: ① The average number of mutations in CEBPAsm and CEBPAdm AML was comparable, but not significant (P = 0.17). ② CEBPAdm patients exhibited more mutations in CSF3R (P = 0.037), GATA2 (P = 0.022), and WT1 (P = 0.046). In contrast, CEBPAsm patients more frequently harbored mutations in NPM1 (P = 0.000), FLT3-ITD (P = 0.025) and NOTCH2 (P = 0.043), as well as mutations in signaling pathways and spliceosomes (P = 0.064, P = 0.027, respectively). ③ Patients with CEBPAsm/TET2mut or CEBPAsm /GATA2mut had higher platelet counts (both P = 0.011), while patients with CEBPAdm /TET2mut had significantly higher hemoglobin levels (P = 0.009). The CR rate of patients with FLT3-ITD mutations was significantly lower in the CEBPAsm group than the CEBPAdm group (P = 0.028). CONCLUSIONS: CEBPAsm and CEBPAdm AML are each associated with their own complex co-mutation cluster. Some co-mutations influence the clinical features and CR rate differently in patients with different CEBPA mutational status.

Molecular genetic and clinical characterization of acute myeloid leukemia with trisomy 8 as the sole chromosome abnormality.

INTRODUCTION: The aim of the study was to determine molecular genetic and clinical characterization of acute myeloid leukemia (AML) with trisomy 8 as the sole chromosome abnormality, a recurrent but rare chromosomal abnormality in AML. METHODS: Interphase fluorescence in situ hybridization, reverse transcriptase-quantitative polymerase chain reaction for gene rearrangement and next-generation sequencing (NGS) were performed on sole trisomy 8 AML patients. RESULTS: A total of 35 AML patients with trisomy 8 as the sole chromosome abnormality were screened. The most frequently mutated genes were DNMT3A(37.1%), RUNX1(28.6%), FLT3-ITD(28.6%), IDH2(22.9%), NPM1(17.1%), and ASXL1 (14.3%). The sole +8 AML patients exhibited more mutations in RUNX1 (28.6% vs. 4.8%, P = 0.001) and ASXL1 (14.3% vs. 4.8%, P = 0.039) by comparing with normal karyotype AML (NK AML) patients(n = 63). The sole +8 AML patients(n = 35) with RUNX1 or IDH2 mutations showed significantly lower WBC counts, while FLT3-ITD showed higher white blood cell (WBC) counts as compared to the corresponding wild-type groups. Total of 45.7% patients achieved complete remission (CR) after the first induction therapy. The CR rate of patients with FLT3-ITD or IDH1 mutation was significantly lower than that in the corresponding wild-type cases (P = 0.047, 0.005, respectively). The median overall survival (OS) and disease-free survival (PFS) were 18.0 (95% CI: 10.8-25.2) and 10 (95% CI: 6.7-13.3) months, respectively. FLT3-ITD mutations and allogeneic hematopoietic stem cell transplantation (allo-HSCT) were independent prognostic markers for OS in multivariable analysis. CONCLUSION: The results suggest a possible association between trisomy 8 and additional mutations that may influence clinical feature and prognosis.