Transition metal phosphides hold great potential as anode materials owing to their high theoretical capacity and modest plateau, while the unstable structure and unsatisfactory reaction kinetics ...limited their practical applications. Herein, a flower-like Ni2P/CoP@rGO heterostructures is rationally designed and used as the anode for lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). The Ni2P/CoP@rGO heterostructures possesses abundant heterointerfaces, plentiful vacancies and high specific surfaces to improve Li-ion/Na-ion transport kinetics and increase reaction active sites. The introduction of graphene enhances structural stability and accelerates the charge transfer rate. Therefore, the Ni2P/CoP@rGO delivers an ultrahigh capacity of 196.4 mAh g−1 at 10 A g−1 after 5000 cycles for LIBs, and 103.7 mAh g−1 at 3 A g−1 after 800 cycles for SIBs. Meanwhile, the Ni2P/CoP@rGO-based Li-ion full cell can exhibit ultra-stable electrochemical performance (240.2 mAh g−1 after 40 cycles at 50 mA g−1). Furthermore, in-situ X-ray diffraction (XRD) and ex-situ characterization reveal the Li-ion/Na-ion conversion behavior within the Ni2P/CoP@rGO. This work demonstrates that rationally designing heterostructure materials is a feasible strategy for achieving high-performance energy storage.
•The Ni2P/CoP@rGO heterostructure possesses fast reaction kinetics.•Graphene alleviates volume expansion and improves conductivity.•The reaction mechanism of Ni2P/CoP@rGO is analyzed by in-situ XRD.•The Ni2P/CoP@rGO exhibits excellent electrochemical performance in LIB/SIB.
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•v-CoSe2/CoP with heterogeneous interfaces and rich anionic vacancies is fabricated.•The v-CoSe2/CoP displays a unique honeycomb-like structure.•The heterostructure and Se- and ...P-vacancies can boost charge transfer kinetics.•An asymmetric SC is assembled by using v-CoSe2/CoP as cathode and AC as anode.•Combination of heterostructure with defect engineering might be a feasible strategy.
CoSe2/CoP with rich Se- and P-vacancies and heterogeneous interfaces (v-CoSe2/CoP) is grown on the surface of nickel foam via a two-step strategy: electrodeposition and NaBH4 reduction, which can be used as the cathode material in asymmetric supercapacitors. The SEM characterization reveals the honeycomb-like structure of the v-CoSe2/CoP, and the results of EPR, XPS and HRTEM reveal the existence of anionic vacancies and heterogeneous interfaces in the v-CoSe2/CoP. The as-fabricated v-CoSe2/CoP exhibits high specific capacitance (3206 mF cm−2 at 1.0 mA cm−2) and cyclic stability (91 % capacitance retention after 2000 cycles). An asymmetric supercapacitor is assembled by using the v-CoSe2/CoP and activated carbon (AC) as cathode and anode materials, respectively, which displays a high energy density of 40.6 Wh kg−1 at the power density of 211.5 W kg−1. The outstanding electrochemical performances of the v-CoSe2/CoP might be ascribed to the synergistic effects of Se- and P-vacancies and the heterogeneous interfaces in the v-CoSe2/CoP.
Hollow nanostructures with mesoporous shells are attractive for their advantageous structure‐dependent high‐efficiency electrochemical catalytic performances. In this work, a novel nanostructure of ...Fe‐doped CoP hollow triangle plate arrays (Fe–CoP HTPAs) with unique mesoporous shells is designed and synthesized through a room‐temperature postsynthetic ligand exchange reaction followed by a facile phosphorization treatment. The mild postsynthetic ligand exchange reaction of the presynthesized ZIF‐67 TPAs with K4Fe(CN)6 in an aqueous solution at room temperature is of critical importance in achieving the final hollow nanostructure, which results in the production of CoFe(II)‐PBA HTPAs that not only determine the formation of the interior voids in the nanostructure, but also provide the doping of Fe atoms to the CoP lattice. As expected, the as‐prepared mesoporous Fe–CoP HTPAs exhibit pronounced activity for water splitting owing to the advantages of abundant active reaction sites, short electron and ion pathways, and favorable hydrogen adsorption free energy (ΔGH*). For the hydrogen and oxygen evolution reactions with the Fe–CoP HTPAs in alkaline medium, the low overpotentials of 98 and 230 mV are observed, respectively, and the required cell voltage toward overall water splitting is only as low as 1.59 V for the driving current density of 10 mA cm−2.
A room‐temperature postsynthetic ligand exchange reaction followed by a facile phosphorization treatment is demonstrated to construct Fe‐doped CoP hollow triangle plate arrays with unique mesoporous shells aiming at achieving an active, stable, and low‐cost electrocatalyst toward overall water splitting.
Mechanisms of Autophagy Initiation Hurley, James H; Young, Lindsey N
Annual review of biochemistry,
06/2017, Letnik:
86, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Autophagy is the process of cellular self-eating by a double-membrane organelle, the autophagosome. A range of signaling processes converge on two protein complexes to initiate autophagy: the ULK1 ...(unc51-like autophagy activating kinase 1) protein kinase complex and the PI3KC3-C1 (class III phosphatidylinositol 3-kinase complex I) lipid kinase complex. Some 90% of the mass of these large protein complexes consists of noncatalytic domains and subunits, and the ULK1 complex has essential noncatalytic activities. Structural studies of these complexes have shed increasing light on the regulation of their catalytic and noncatalytic activities in autophagy initiation. The autophagosome is thought to nucleate from vesicles containing the integral membrane protein Atg9 (autophagy-related 9), COPII (coat protein complex II) vesicles, and possibly other sources. In the wake of reconstitution and super-resolution imaging studies, we are beginning to understand how the ULK1 and PI3KC3-C1 complexes might coordinate the nucleation and fusion of Atg9 and COPII vesicles at the start of autophagosome biogenesis.
CoP nanoparticle-loaded N-doped graphitic C3N4 nanosheets (CoP/N-g-C3N4) were fabricated via a facile three-step method to degrade pharmaceuticals and personal care products (PPCPs) via a ...visible-light-driven (VLD) peroxymonosulfate (PMS) activation system. 2 ppm carbamazepine (CBZ) can be removed completely within 10 min by the VLD-PMS system with a kinetic constant of k = 0.29128 min−1, as 25.8 times compared to that under dark conditions (k = 0.01128 min−1). The experimental and theoretical results showed that the doped graphitic N atoms could modulate the electronic properties of the g-C3N4 nanosheets. Subsequently, the Density Functional Theory (DFT) explained that CoP showed preference to bonding with the nitrogen atoms involved in the newly formed N˭N bond, and the Co‒N bond dramatically enhanced the transfer of photo-generated electrons from the N-g-C3N4 nanosheets. Electron paramagnetic resonance (EPR) tests show that singlet oxygen (1O2) plays a leading role in this case. Moreover, PMS molecules are also tended to be absorbed onto the electron-deficient carbon atoms near the newly formed N˭N bonds for PMS reduction, synergistically enhancing the degradation efficiency for CBZ and benzophenone-3 (BZP). The newly established VLD-PMS activation system was shown to treat the actual sewage in Hong Kong sewage treatment plants (STPs) very well. This work supplements the fundamental theory of radical and non-radical pathways in the sulfate radical (SO4•-)-based advanced oxidation process (SR-AOP) for environmental cleanup purposes.
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•Graphitic N atoms doping modulates the electronic properties of g-C3N4 nanosheets.•1O2 is the predominant ROS over the CoP/N-g-C3N4 nanosheets.•The electrons transferring via Co‒N bond dramatically promote the degradation.•CoP/N-g-C3N4 show convincible potential for the purification of actual sewage.
Concentrating photovoltaic thermal (CPVT) collectors and systems are very popular in both domestic and industrial solar energy applications. CPVT collectors provides incomparably greater thermal and ...electrical outputs compared to stand alone PV or hybrid PVT systems as incoming solar energy is maximised inside the unit via energy-efficient concentrators. Within the scope of this paper, a comprehensive review on CPVT collectors and systems is proposed. For an easier assessment of the findings through state-of-the-art analyses on CPVT collectors, the review is presented in a thematic way. Historical overview of the technology is followed by the detailed description of a CPVT collector with main system elements and thermodynamic performance definitions. The review also covers thermal and electrical performance analysis of CPVT collectors using water or air as working fluid, analytical, numerical, simulation and experimental works for performance evaluation of different design configurations of CPVT systems and qualitative analysis of electrical and thermal energy generation. The impacts of concentrator type and concentration ratio on system efficiency, operating temperature and coefficient of performance (COP) are analysed in detail. It is observed from the findings that CPVT collectors are promising devices in market, and they have a good potential to be competitive with conventional power generation systems in the near future.
An efficient and low‐cost electrocatalyst for reversible oxygen electrocatalysis is crucial for improving the performance of rechargeable metal−air batteries. Herein, a novel oxygen vacancy–rich 2D ...porous In‐doped CoO/CoP heterostructure (In‐CoO/CoP FNS) is designed and developed by a facile free radicals–induced strategy as an effective bifunctional electrocatalyst for rechargeable Zn–air batteries. The electron spin resonance and X‐ray absorption near edge spectroscopy provide clear evidence that abundant oxygen vacancies are formed in the interface of In‐CoO/CoP FNS. Owing to abundant oxygen vacancies, porous heterostructure, and multiple components, In‐CoO/CoP FNS exhibits excellent oxygen reduction reaction activity with a positive half‐wave potential of 0.81 V and superior oxygen evolution reaction activity with a low overpotential of 365 mV at 10 mA cm−2. Moreover, a home‐made Zn–air battery with In‐CoO/CoP FNS as an air cathode delivers a large power density of 139.4 mW cm−2, a high energy density of 938 Wh kgZn−1, and can be steadily cycled over 130 h at 10 mA cm−2, demonstrating great application potential in rechargeable metal–air batteries.
A novel In‐doped CoO/CoP heterostructure with abundant oxygen vacancies is synthesized for the first time via a facile free radicals–induced strategy. Benefitting from the unique composition/structure‐dependent merits, the newly developed catalyst exhibits remarkably improved electrocatalytic performance for both the oxygen reduction reaction and oxygen evolution reaction, as well as potential practicability in rechargeable Zn–air batteries.
A novel strategy of boosting electrochemical performance of hybrid supercapacitor cathode based on interface engineering by fabrication of Schottky-type conjunction is proposed. The electrode is ...composed of binder free 3D CoP nanoflowers decorated by CeO2 nanoparticles, which was directly grown on nickel foam, forming a conjunction interface. Compared to CoP, the CeO2@CoP electrode exhibits remarkable enhanced electrochemical performance. The significantly boosted performance can be attributed to the CeO2@CoP interface, which promotes electrons migration from CoP to CeO2 and eventually forms positive holes on CoP. These positive holes can easily capture more OH−, creating more active sites for redox process. Furthermore, a hybrid supercapacitor full cell composed of CeO2@CoP and activated carbon was assembled, which exhibits outstanding energy storage performance with a specific capacity of 486.5 mC cm−2 at 1 mA cm−2 and outstanding cycle stability of 89% after 5000 cycles. The energy density is 55.4 Wh kg−1 at a power density of 955.9 W kg−1. This work not only demonstrates that CeO2 is an attractive additive for supercapacitor electrodes, but also provides an experimental/theoretical understanding of the enhanced electrochemical performance by electrons migration process on CeO2@CoP interfaces, which is important for the design of supercapacitors.
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•A novel strategy of boosting performance of CeO2@CoP supercapacitor electrodes based on Schottky-type conjunction interface engineering was presented.•The CeO2@CoP/NF electrode exhibits boosting electrochemical properties of excellent specific capacity and outstanding rate capability.•The electrons transfer from CoP(112) to CeO2(111) surface was calculated by DFT calculation.
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